linux/mm/mm_init.c

2693 lines
75 KiB

mm: adjust vm_committed_as_batch according to vm overcommit policy When checking a performance change for will-it-scale scalability mmap test [1], we found very high lock contention for spinlock of percpu counter 'vm_committed_as': 94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave 48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap; 45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap; Actually this heavy lock contention is not always necessary. The 'vm_committed_as' needs to be very precise when the strict OVERCOMMIT_NEVER policy is set, which requires a rather small batch number for the percpu counter. So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and lift it to 64X for OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Also add a sysctl handler to adjust it when the policy is reconfigured. Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T desktop, and 2097%(20X) on a 4S/72C/144T server. We tested with test platforms in 0day (server, desktop and laptop), and 80%+ platforms shows improvements with that test. And whether it shows improvements depends on if the test mmap size is bigger than the batch number computed. And if the lift is 16X, 1/3 of the platforms will show improvements, though it should help the mmap/unmap usage generally, as Michal Hocko mentioned: : I believe that there are non-synthetic worklaods which would benefit from : a larger batch. E.g. large in memory databases which do large mmaps : during startups from multiple threads. [1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/ Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Qian Cai <cai@lca.pw> Cc: Kees Cook <keescook@chromium.org> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: kernel test robot <rong.a.chen@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1589611660-89854-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1592725000-73486-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1594389708-60781-5-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-06 23:23:15 -07:00
mm: report per-page metadata information Today, we do not have any observability of per-page metadata and how much it takes away from the machine capacity. Thus, we want to describe the amount of memory that is going towards per-page metadata, which can vary depending on build configuration, machine architecture, and system use. This patch adds 2 fields to /proc/vmstat that can used as shown below: Accounting per-page metadata allocated by boot-allocator: /proc/vmstat:nr_memmap_boot * PAGE_SIZE Accounting per-page metadata allocated by buddy-allocator: /proc/vmstat:nr_memmap * PAGE_SIZE Accounting total Perpage metadata allocated on the machine: (/proc/vmstat:nr_memmap_boot + /proc/vmstat:nr_memmap) * PAGE_SIZE Utility for userspace: Observability: Describe the amount of memory overhead that is going to per-page metadata on the system at any given time since this overhead is not currently observable. Debugging: Tracking the changes or absolute value in struct pages can help detect anomalies as they can be correlated with other metrics in the machine (e.g., memtotal, number of huge pages, etc). page_ext overheads: Some kernel features such as page_owner page_table_check that use page_ext can be optionally enabled via kernel parameters. Having the total per-page metadata information helps users precisely measure impact. Furthermore, page-metadata metrics will reflect the amount of struct pages reliquished (or overhead reduced) when hugetlbfs pages are reserved which will vary depending on whether hugetlb vmemmap optimization is enabled or not. For background and results see: lore.kernel.org/all/20240220214558.3377482-1-souravpanda@google.com Link: https://lkml.kernel.org/r/20240605222751.1406125-1-souravpanda@google.com Signed-off-by: Sourav Panda <souravpanda@google.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Chen Linxuan <chenlinxuan@uniontech.com> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ivan Babrou <ivan@cloudflare.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Shakeel Butt <shakeelb@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tomas Mudrunka <tomas.mudrunka@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Xu <weixugc@google.com> Cc: Yang Yang <yang.yang29@zte.com.cn> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-05 22:27:51 +00:00
kexec: add Kexec HandOver (KHO) generation helpers Add the infrastructure to generate Kexec HandOver metadata. Kexec HandOver is a mechanism that allows Linux to preserve state - arbitrary properties as well as memory locations - across kexec. It does so using 2 concepts: 1) KHO FDT - Every KHO kexec carries a KHO specific flattened device tree blob that describes preserved memory regions. Device drivers can register to KHO to serialize and preserve their states before kexec. 2) Scratch Regions - CMA regions that we allocate in the first kernel. CMA gives us the guarantee that no handover pages land in those regions, because handover pages must be at a static physical memory location. We use these regions as the place to load future kexec images so that they won't collide with any handover data. Link: https://lkml.kernel.org/r/20250509074635.3187114-5-changyuanl@google.com Signed-off-by: Alexander Graf <graf@amazon.com> Co-developed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Co-developed-by: Pratyush Yadav <ptyadav@amazon.de> Signed-off-by: Pratyush Yadav <ptyadav@amazon.de> Co-developed-by: Changyuan Lyu <changyuanl@google.com> Signed-off-by: Changyuan Lyu <changyuanl@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anthony Yznaga <anthony.yznaga@oracle.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ashish Kalra <ashish.kalra@amd.com> Cc: Ben Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Gowans <jgowans@amazon.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rob Herring <robh@kernel.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Lendacky <thomas.lendacky@amd.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-09 00:46:22 -07:00
mm/hugetlb: convert cmdline parameters from setup to early Convert the cmdline parameters (hugepagesz, hugepages, default_hugepagesz and hugetlb_free_vmemmap) to early parameters. Since parse_early_param might run before MMU setups on some platforms (powerpc), validation of huge page sizes as specified in command line parameters would fail. So instead, for the hstate-related values, just record the them and parse them on demand, from hugetlb_bootmem_alloc. The allocation of hugetlb bootmem pages is now done in hugetlb_bootmem_alloc, which is called explicitly at the start of mm_core_init(). core_initcall would be too late, as that happens with memblock already torn down. This change will allow earlier allocation and initialization of bootmem hugetlb pages later on. No functional change intended. Link: https://lkml.kernel.org/r/20250228182928.2645936-8-fvdl@google.com Signed-off-by: Frank van der Linden <fvdl@google.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-28 18:29:08 +00:00
mm: split out mm_init and memblock declarations from internal.h Patch series "mm: split a couple of headers from internal.h", v2. mm/internal.h becomes more and more bloated. Split declarations related to mm_init, memblock, vmalloc and sparse into new headers. This patch (of 3): mm/internal.h becomes more and more bloated. Move declarations for related to mm/mm_init.c and mm/memblock.c to a new mm/mm_init.h header. No functional changes. [rppt@kernel.org: split stubfs from internal.h to mm_init.h] Link: https://lore.kernel.org/alJd1BLypyK9Mpaw@kernel.org Link: https://lore.kernel.org/20260709-internal-h-v2-0-695631425968@kernel.org Link: https://lore.kernel.org/20260709-internal-h-v2-1-695631425968@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Muchun Song <muchun.song@linux.dev> Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Lorenzo Stoakes <ljs@kernel.org> Acked-by: Pratyush Yadav <pratyush@kernel.org> Acked-by: SJ Park <sj@kernel.org> Cc: Alexander Graf <graf@amazon.com> Cc: Alexander Potapenko <glider@google.com> Cc: Brendan Jackman <jackmanb@google.com> Cc: Brendan Jackman <brendan.jackman@linux.dev> Cc: Dennis Zhou <dennis@kernel.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Marco Elver <elver@google.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-07-09 13:00:03 +03:00
arch, mm: set max_mapnr when allocating memory map for FLATMEM max_mapnr is essentially the size of the memory map for systems that use FLATMEM. There is no reason to calculate it in each and every architecture when it's anyway calculated in alloc_node_mem_map(). Drop setting of max_mapnr from architecture code and set it once in alloc_node_mem_map(). While on it, move definition of mem_map and max_mapnr to mm/mm_init.c so there won't be two copies for MMU and !MMU variants. Link: https://lkml.kernel.org/r/20250313135003.836600-10-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86] Tested-by: Mark Brown <broonie@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Guo Ren (csky) <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russel King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-13 15:49:59 +02:00
arch, mm: set high_memory in free_area_init() high_memory defines upper bound on the directly mapped memory. This bound is defined by the beginning of ZONE_HIGHMEM when a system has high memory and by the end of memory otherwise. All this is known to generic memory management initialization code that can set high_memory while initializing core mm structures. Add a generic calculation of high_memory to free_area_init() and remove per-architecture calculation except for the architectures that set and use high_memory earlier than that. Link: https://lkml.kernel.org/r/20250313135003.836600-11-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86] Tested-by: Mark Brown <broonie@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Guo Ren (csky) <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russel King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-13 15:50:00 +02:00
mm: rename my_zero_pfn() to zero_pfn() my_zero_pfn() is a silly name. Rename zero_pfn variable to zero_page_pfn and my_zero_pfn() function to zero_pfn(). While on it, move extern declarations of zero_page_pfn outside the functions that use it and add a comment about what ZERO_PAGE is. Link: https://lkml.kernel.org/r/20260211103141.3215197-3-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-11 12:31:39 +02:00
mm: don't special case !MMU for is_zero_pfn() and my_zero_pfn() Patch series "arch, mm: consolidate empty_zero_page", v3. These patches cleanup handling of ZERO_PAGE() and zero_pfn. This patch (of 4): nommu architectures have empty_zero_page and define ZERO_PAGE() and although they don't really use it to populate page tables, there is no reason to hardwire !MMU implementation of is_zero_pfn() and my_zero_pfn() to 0. Drop #ifdef CONFIG_MMU around implementations of is_zero_pfn() and my_zero_pfn() and remove !MMU version. While on it, make zero_pfn __ro_after_init. Link: https://lkml.kernel.org/r/20260211103141.3215197-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20260211103141.3215197-2-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-11 12:31:38 +02:00
arch, mm: consolidate empty_zero_page Reduce 22 declarations of empty_zero_page to 3 and 23 declarations of ZERO_PAGE() to 4. Every architecture defines empty_zero_page that way or another, but for the most of them it is always a page aligned page in BSS and most definitions of ZERO_PAGE do virt_to_page(empty_zero_page). Move Linus vetted x86 definition of empty_zero_page and ZERO_PAGE() to the core MM and drop these definitions in architectures that do not implement colored zero page (MIPS and s390). ZERO_PAGE() remains a macro because turning it to a wrapper for a static inline causes severe pain in header dependencies. For the most part the change is mechanical, with these being noteworthy: * alpha: aliased empty_zero_page with ZERO_PGE that was also used for boot parameters. Switching to a generic empty_zero_page removes the aliasing and keeps ZERO_PGE for boot parameters only * arm64: uses __pa_symbol() in ZERO_PAGE() so that definition of ZERO_PAGE() is kept intact. * m68k/parisc/um: allocated empty_zero_page from memblock, although they do not support zero page coloring and having it in BSS will work fine. * sparc64 can have empty_zero_page in BSS rather allocate it, but it can't use virt_to_page() for BSS. Keep it's definition of ZERO_PAGE() but instead of allocating it, make mem_map_zero point to empty_zero_page. * sh: used empty_zero_page for boot parameters at the very early boot. Rename the parameters page to boot_params_page and let sh use the generic empty_zero_page. * hexagon: had an amusing comment about empty_zero_page /* A handy thing to have if one has the RAM. Declared in head.S */ that unfortunately had to go :) Link: https://lkml.kernel.org/r/20260211103141.3215197-4-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Helge Deller <deller@gmx.de> [parisc] Tested-by: Helge Deller <deller@gmx.de> [parisc] Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Magnus Lindholm <linmag7@gmail.com> [alpha] Acked-by: Dinh Nguyen <dinguyen@kernel.org> [nios2] Acked-by: Andreas Larsson <andreas@gaisler.com> [sparc] Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: David S. Miller <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-11 12:31:40 +02:00
arch, mm: consolidate empty_zero_page Reduce 22 declarations of empty_zero_page to 3 and 23 declarations of ZERO_PAGE() to 4. Every architecture defines empty_zero_page that way or another, but for the most of them it is always a page aligned page in BSS and most definitions of ZERO_PAGE do virt_to_page(empty_zero_page). Move Linus vetted x86 definition of empty_zero_page and ZERO_PAGE() to the core MM and drop these definitions in architectures that do not implement colored zero page (MIPS and s390). ZERO_PAGE() remains a macro because turning it to a wrapper for a static inline causes severe pain in header dependencies. For the most part the change is mechanical, with these being noteworthy: * alpha: aliased empty_zero_page with ZERO_PGE that was also used for boot parameters. Switching to a generic empty_zero_page removes the aliasing and keeps ZERO_PGE for boot parameters only * arm64: uses __pa_symbol() in ZERO_PAGE() so that definition of ZERO_PAGE() is kept intact. * m68k/parisc/um: allocated empty_zero_page from memblock, although they do not support zero page coloring and having it in BSS will work fine. * sparc64 can have empty_zero_page in BSS rather allocate it, but it can't use virt_to_page() for BSS. Keep it's definition of ZERO_PAGE() but instead of allocating it, make mem_map_zero point to empty_zero_page. * sh: used empty_zero_page for boot parameters at the very early boot. Rename the parameters page to boot_params_page and let sh use the generic empty_zero_page. * hexagon: had an amusing comment about empty_zero_page /* A handy thing to have if one has the RAM. Declared in head.S */ that unfortunately had to go :) Link: https://lkml.kernel.org/r/20260211103141.3215197-4-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Helge Deller <deller@gmx.de> [parisc] Tested-by: Helge Deller <deller@gmx.de> [parisc] Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Magnus Lindholm <linmag7@gmail.com> [alpha] Acked-by: Dinh Nguyen <dinguyen@kernel.org> [nios2] Acked-by: Andreas Larsson <andreas@gaisler.com> [sparc] Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: David S. Miller <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-11 12:31:40 +02:00
mm: cache struct page for empty_zero_page and return it from ZERO_PAGE() For most architectures every invocation of ZERO_PAGE() does virt_to_page(empty_zero_page). But empty_zero_page is in BSS and it is enough to get its struct page once at initialization time and then use it whenever a zero page should be accessed. Add yet another __zero_page variable that will be initialized as virt_to_page(empty_zero_page) for most architectures in a weak arch_setup_zero_pages() function. For architectures that use colored zero pages (MIPS and s390) rename their setup_zero_pages() to arch_setup_zero_pages() and make it global rather than static. For architectures that cannot use virt_to_page() for BSS (arm64 and sparc64) add override of arch_setup_zero_pages(). Link: https://lkml.kernel.org/r/20260211103141.3215197-5-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-11 12:31:41 +02:00
arch, mm: consolidate empty_zero_page Reduce 22 declarations of empty_zero_page to 3 and 23 declarations of ZERO_PAGE() to 4. Every architecture defines empty_zero_page that way or another, but for the most of them it is always a page aligned page in BSS and most definitions of ZERO_PAGE do virt_to_page(empty_zero_page). Move Linus vetted x86 definition of empty_zero_page and ZERO_PAGE() to the core MM and drop these definitions in architectures that do not implement colored zero page (MIPS and s390). ZERO_PAGE() remains a macro because turning it to a wrapper for a static inline causes severe pain in header dependencies. For the most part the change is mechanical, with these being noteworthy: * alpha: aliased empty_zero_page with ZERO_PGE that was also used for boot parameters. Switching to a generic empty_zero_page removes the aliasing and keeps ZERO_PGE for boot parameters only * arm64: uses __pa_symbol() in ZERO_PAGE() so that definition of ZERO_PAGE() is kept intact. * m68k/parisc/um: allocated empty_zero_page from memblock, although they do not support zero page coloring and having it in BSS will work fine. * sparc64 can have empty_zero_page in BSS rather allocate it, but it can't use virt_to_page() for BSS. Keep it's definition of ZERO_PAGE() but instead of allocating it, make mem_map_zero point to empty_zero_page. * sh: used empty_zero_page for boot parameters at the very early boot. Rename the parameters page to boot_params_page and let sh use the generic empty_zero_page. * hexagon: had an amusing comment about empty_zero_page /* A handy thing to have if one has the RAM. Declared in head.S */ that unfortunately had to go :) Link: https://lkml.kernel.org/r/20260211103141.3215197-4-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Helge Deller <deller@gmx.de> [parisc] Tested-by: Helge Deller <deller@gmx.de> [parisc] Reviewed-by: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Magnus Lindholm <linmag7@gmail.com> [alpha] Acked-by: Dinh Nguyen <dinguyen@kernel.org> [nios2] Acked-by: Andreas Larsson <andreas@gaisler.com> [sparc] Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: David S. Miller <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-11 12:31:40 +02:00
alloc_tag: support for page allocation tag compression Implement support for storing page allocation tag references directly in the page flags instead of page extensions. sysctl.vm.mem_profiling boot parameter it extended to provide a way for a user to request this mode. Enabling compression eliminates memory overhead caused by page_ext and results in better performance for page allocations. However this mode will not work if the number of available page flag bits is insufficient to address all kernel allocations. Such condition can happen during boot or when loading a module. If this condition is detected, memory allocation profiling gets disabled with an appropriate warning. By default compression mode is disabled. Link: https://lkml.kernel.org/r/20241023170759.999909-7-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: Daniel Gomez <da.gomez@samsung.com> Cc: David Hildenbrand <david@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: David Rientjes <rientjes@google.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Minchan Kim <minchan@google.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Petr Pavlu <petr.pavlu@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Sourav Panda <souravpanda@google.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Huth <thuth@redhat.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xiongwei Song <xiongwei.song@windriver.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-23 10:07:59 -07:00
mm: multi-gen LRU: groundwork Evictable pages are divided into multiple generations for each lruvec. The youngest generation number is stored in lrugen->max_seq for both anon and file types as they are aged on an equal footing. The oldest generation numbers are stored in lrugen->min_seq[] separately for anon and file types as clean file pages can be evicted regardless of swap constraints. These three variables are monotonically increasing. Generation numbers are truncated into order_base_2(MAX_NR_GENS+1) bits in order to fit into the gen counter in folio->flags. Each truncated generation number is an index to lrugen->lists[]. The sliding window technique is used to track at least MIN_NR_GENS and at most MAX_NR_GENS generations. The gen counter stores a value within [1, MAX_NR_GENS] while a page is on one of lrugen->lists[]. Otherwise it stores 0. There are two conceptually independent procedures: "the aging", which produces young generations, and "the eviction", which consumes old generations. They form a closed-loop system, i.e., "the page reclaim". Both procedures can be invoked from userspace for the purposes of working set estimation and proactive reclaim. These techniques are commonly used to optimize job scheduling (bin packing) in data centers [1][2]. To avoid confusion, the terms "hot" and "cold" will be applied to the multi-gen LRU, as a new convention; the terms "active" and "inactive" will be applied to the active/inactive LRU, as usual. The protection of hot pages and the selection of cold pages are based on page access channels and patterns. There are two access channels: one through page tables and the other through file descriptors. The protection of the former channel is by design stronger because: 1. The uncertainty in determining the access patterns of the former channel is higher due to the approximation of the accessed bit. 2. The cost of evicting the former channel is higher due to the TLB flushes required and the likelihood of encountering the dirty bit. 3. The penalty of underprotecting the former channel is higher because applications usually do not prepare themselves for major page faults like they do for blocked I/O. E.g., GUI applications commonly use dedicated I/O threads to avoid blocking rendering threads. There are also two access patterns: one with temporal locality and the other without. For the reasons listed above, the former channel is assumed to follow the former pattern unless VM_SEQ_READ or VM_RAND_READ is present; the latter channel is assumed to follow the latter pattern unless outlying refaults have been observed [3][4]. The next patch will address the "outlying refaults". Three macros, i.e., LRU_REFS_WIDTH, LRU_REFS_PGOFF and LRU_REFS_MASK, used later are added in this patch to make the entire patchset less diffy. A page is added to the youngest generation on faulting. The aging needs to check the accessed bit at least twice before handing this page over to the eviction. The first check takes care of the accessed bit set on the initial fault; the second check makes sure this page has not been used since then. This protocol, AKA second chance, requires a minimum of two generations, hence MIN_NR_GENS. [1] https://dl.acm.org/doi/10.1145/3297858.3304053 [2] https://dl.acm.org/doi/10.1145/3503222.3507731 [3] https://lwn.net/Articles/495543/ [4] https://lwn.net/Articles/815342/ Link: https://lkml.kernel.org/r/20220918080010.2920238-6-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Acked-by: Brian Geffon <bgeffon@google.com> Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name> Acked-by: Steven Barrett <steven@liquorix.net> Acked-by: Suleiman Souhlal <suleiman@google.com> Tested-by: Daniel Byrne <djbyrne@mtu.edu> Tested-by: Donald Carr <d@chaos-reins.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru> Tested-by: Shuang Zhai <szhai2@cs.rochester.edu> Tested-by: Sofia Trinh <sofia.trinh@edi.works> Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Barry Song <baohua@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Larabel <Michael@MichaelLarabel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-18 02:00:02 -06:00
mm: multi-gen LRU: groundwork Evictable pages are divided into multiple generations for each lruvec. The youngest generation number is stored in lrugen->max_seq for both anon and file types as they are aged on an equal footing. The oldest generation numbers are stored in lrugen->min_seq[] separately for anon and file types as clean file pages can be evicted regardless of swap constraints. These three variables are monotonically increasing. Generation numbers are truncated into order_base_2(MAX_NR_GENS+1) bits in order to fit into the gen counter in folio->flags. Each truncated generation number is an index to lrugen->lists[]. The sliding window technique is used to track at least MIN_NR_GENS and at most MAX_NR_GENS generations. The gen counter stores a value within [1, MAX_NR_GENS] while a page is on one of lrugen->lists[]. Otherwise it stores 0. There are two conceptually independent procedures: "the aging", which produces young generations, and "the eviction", which consumes old generations. They form a closed-loop system, i.e., "the page reclaim". Both procedures can be invoked from userspace for the purposes of working set estimation and proactive reclaim. These techniques are commonly used to optimize job scheduling (bin packing) in data centers [1][2]. To avoid confusion, the terms "hot" and "cold" will be applied to the multi-gen LRU, as a new convention; the terms "active" and "inactive" will be applied to the active/inactive LRU, as usual. The protection of hot pages and the selection of cold pages are based on page access channels and patterns. There are two access channels: one through page tables and the other through file descriptors. The protection of the former channel is by design stronger because: 1. The uncertainty in determining the access patterns of the former channel is higher due to the approximation of the accessed bit. 2. The cost of evicting the former channel is higher due to the TLB flushes required and the likelihood of encountering the dirty bit. 3. The penalty of underprotecting the former channel is higher because applications usually do not prepare themselves for major page faults like they do for blocked I/O. E.g., GUI applications commonly use dedicated I/O threads to avoid blocking rendering threads. There are also two access patterns: one with temporal locality and the other without. For the reasons listed above, the former channel is assumed to follow the former pattern unless VM_SEQ_READ or VM_RAND_READ is present; the latter channel is assumed to follow the latter pattern unless outlying refaults have been observed [3][4]. The next patch will address the "outlying refaults". Three macros, i.e., LRU_REFS_WIDTH, LRU_REFS_PGOFF and LRU_REFS_MASK, used later are added in this patch to make the entire patchset less diffy. A page is added to the youngest generation on faulting. The aging needs to check the accessed bit at least twice before handing this page over to the eviction. The first check takes care of the accessed bit set on the initial fault; the second check makes sure this page has not been used since then. This protocol, AKA second chance, requires a minimum of two generations, hence MIN_NR_GENS. [1] https://dl.acm.org/doi/10.1145/3297858.3304053 [2] https://dl.acm.org/doi/10.1145/3503222.3507731 [3] https://lwn.net/Articles/495543/ [4] https://lwn.net/Articles/815342/ Link: https://lkml.kernel.org/r/20220918080010.2920238-6-yuzhao@google.com Signed-off-by: Yu Zhao <yuzhao@google.com> Acked-by: Brian Geffon <bgeffon@google.com> Acked-by: Jan Alexander Steffens (heftig) <heftig@archlinux.org> Acked-by: Oleksandr Natalenko <oleksandr@natalenko.name> Acked-by: Steven Barrett <steven@liquorix.net> Acked-by: Suleiman Souhlal <suleiman@google.com> Tested-by: Daniel Byrne <djbyrne@mtu.edu> Tested-by: Donald Carr <d@chaos-reins.com> Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com> Tested-by: Konstantin Kharlamov <Hi-Angel@yandex.ru> Tested-by: Shuang Zhai <szhai2@cs.rochester.edu> Tested-by: Sofia Trinh <sofia.trinh@edi.works> Tested-by: Vaibhav Jain <vaibhav@linux.ibm.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Barry Song <baohua@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Larabel <Michael@MichaelLarabel.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-18 02:00:02 -06:00
mm: adjust vm_committed_as_batch according to vm overcommit policy When checking a performance change for will-it-scale scalability mmap test [1], we found very high lock contention for spinlock of percpu counter 'vm_committed_as': 94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave 48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap; 45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap; Actually this heavy lock contention is not always necessary. The 'vm_committed_as' needs to be very precise when the strict OVERCOMMIT_NEVER policy is set, which requires a rather small batch number for the percpu counter. So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and lift it to 64X for OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Also add a sysctl handler to adjust it when the policy is reconfigured. Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T desktop, and 2097%(20X) on a 4S/72C/144T server. We tested with test platforms in 0day (server, desktop and laptop), and 80%+ platforms shows improvements with that test. And whether it shows improvements depends on if the test mmap size is bigger than the batch number computed. And if the lift is 16X, 1/3 of the platforms will show improvements, though it should help the mmap/unmap usage generally, as Michal Hocko mentioned: : I believe that there are non-synthetic worklaods which would benefit from : a larger batch. E.g. large in memory databases which do large mmaps : during startups from multiple threads. [1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/ Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Qian Cai <cai@lca.pw> Cc: Kees Cook <keescook@chromium.org> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: kernel test robot <rong.a.chen@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1589611660-89854-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1592725000-73486-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1594389708-60781-5-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-06 23:23:15 -07:00
mm: adjust vm_committed_as_batch according to vm overcommit policy When checking a performance change for will-it-scale scalability mmap test [1], we found very high lock contention for spinlock of percpu counter 'vm_committed_as': 94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave 48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap; 45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap; Actually this heavy lock contention is not always necessary. The 'vm_committed_as' needs to be very precise when the strict OVERCOMMIT_NEVER policy is set, which requires a rather small batch number for the percpu counter. So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and lift it to 64X for OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Also add a sysctl handler to adjust it when the policy is reconfigured. Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T desktop, and 2097%(20X) on a 4S/72C/144T server. We tested with test platforms in 0day (server, desktop and laptop), and 80%+ platforms shows improvements with that test. And whether it shows improvements depends on if the test mmap size is bigger than the batch number computed. And if the lift is 16X, 1/3 of the platforms will show improvements, though it should help the mmap/unmap usage generally, as Michal Hocko mentioned: : I believe that there are non-synthetic worklaods which would benefit from : a larger batch. E.g. large in memory databases which do large mmaps : during startups from multiple threads. [1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/ Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Qian Cai <cai@lca.pw> Cc: Kees Cook <keescook@chromium.org> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: kernel test robot <rong.a.chen@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1589611660-89854-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1592725000-73486-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1594389708-60781-5-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-06 23:23:15 -07:00
mm: adjust vm_committed_as_batch according to vm overcommit policy When checking a performance change for will-it-scale scalability mmap test [1], we found very high lock contention for spinlock of percpu counter 'vm_committed_as': 94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave 48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap; 45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap; Actually this heavy lock contention is not always necessary. The 'vm_committed_as' needs to be very precise when the strict OVERCOMMIT_NEVER policy is set, which requires a rather small batch number for the percpu counter. So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and lift it to 64X for OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Also add a sysctl handler to adjust it when the policy is reconfigured. Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T desktop, and 2097%(20X) on a 4S/72C/144T server. We tested with test platforms in 0day (server, desktop and laptop), and 80%+ platforms shows improvements with that test. And whether it shows improvements depends on if the test mmap size is bigger than the batch number computed. And if the lift is 16X, 1/3 of the platforms will show improvements, though it should help the mmap/unmap usage generally, as Michal Hocko mentioned: : I believe that there are non-synthetic worklaods which would benefit from : a larger batch. E.g. large in memory databases which do large mmaps : during startups from multiple threads. [1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/ Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Qian Cai <cai@lca.pw> Cc: Kees Cook <keescook@chromium.org> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: kernel test robot <rong.a.chen@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1589611660-89854-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1592725000-73486-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1594389708-60781-5-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-06 23:23:15 -07:00
mm: adjust vm_committed_as_batch according to vm overcommit policy When checking a performance change for will-it-scale scalability mmap test [1], we found very high lock contention for spinlock of percpu counter 'vm_committed_as': 94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave 48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap; 45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap; Actually this heavy lock contention is not always necessary. The 'vm_committed_as' needs to be very precise when the strict OVERCOMMIT_NEVER policy is set, which requires a rather small batch number for the percpu counter. So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and lift it to 64X for OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Also add a sysctl handler to adjust it when the policy is reconfigured. Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T desktop, and 2097%(20X) on a 4S/72C/144T server. We tested with test platforms in 0day (server, desktop and laptop), and 80%+ platforms shows improvements with that test. And whether it shows improvements depends on if the test mmap size is bigger than the batch number computed. And if the lift is 16X, 1/3 of the platforms will show improvements, though it should help the mmap/unmap usage generally, as Michal Hocko mentioned: : I believe that there are non-synthetic worklaods which would benefit from : a larger batch. E.g. large in memory databases which do large mmaps : during startups from multiple threads. [1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/ Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Qian Cai <cai@lca.pw> Cc: Kees Cook <keescook@chromium.org> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: kernel test robot <rong.a.chen@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1589611660-89854-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1592725000-73486-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1594389708-60781-5-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-06 23:23:15 -07:00
mm: adjust vm_committed_as_batch according to vm overcommit policy When checking a performance change for will-it-scale scalability mmap test [1], we found very high lock contention for spinlock of percpu counter 'vm_committed_as': 94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave 48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap; 45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap; Actually this heavy lock contention is not always necessary. The 'vm_committed_as' needs to be very precise when the strict OVERCOMMIT_NEVER policy is set, which requires a rather small batch number for the percpu counter. So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and lift it to 64X for OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Also add a sysctl handler to adjust it when the policy is reconfigured. Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T desktop, and 2097%(20X) on a 4S/72C/144T server. We tested with test platforms in 0day (server, desktop and laptop), and 80%+ platforms shows improvements with that test. And whether it shows improvements depends on if the test mmap size is bigger than the batch number computed. And if the lift is 16X, 1/3 of the platforms will show improvements, though it should help the mmap/unmap usage generally, as Michal Hocko mentioned: : I believe that there are non-synthetic worklaods which would benefit from : a larger batch. E.g. large in memory databases which do large mmaps : during startups from multiple threads. [1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/ Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Qian Cai <cai@lca.pw> Cc: Kees Cook <keescook@chromium.org> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: kernel test robot <rong.a.chen@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1589611660-89854-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1592725000-73486-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1594389708-60781-5-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-06 23:23:15 -07:00
mm: adjust vm_committed_as_batch according to vm overcommit policy When checking a performance change for will-it-scale scalability mmap test [1], we found very high lock contention for spinlock of percpu counter 'vm_committed_as': 94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave 48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap; 45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap; Actually this heavy lock contention is not always necessary. The 'vm_committed_as' needs to be very precise when the strict OVERCOMMIT_NEVER policy is set, which requires a rather small batch number for the percpu counter. So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and lift it to 64X for OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Also add a sysctl handler to adjust it when the policy is reconfigured. Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T desktop, and 2097%(20X) on a 4S/72C/144T server. We tested with test platforms in 0day (server, desktop and laptop), and 80%+ platforms shows improvements with that test. And whether it shows improvements depends on if the test mmap size is bigger than the batch number computed. And if the lift is 16X, 1/3 of the platforms will show improvements, though it should help the mmap/unmap usage generally, as Michal Hocko mentioned: : I believe that there are non-synthetic worklaods which would benefit from : a larger batch. E.g. large in memory databases which do large mmaps : during startups from multiple threads. [1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/ Signed-off-by: Feng Tang <feng.tang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Qian Cai <cai@lca.pw> Cc: Kees Cook <keescook@chromium.org> Cc: Andi Kleen <andi.kleen@intel.com> Cc: Tim Chen <tim.c.chen@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Huang Ying <ying.huang@intel.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: kernel test robot <rong.a.chen@intel.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/1589611660-89854-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1592725000-73486-4-git-send-email-feng.tang@intel.com Link: http://lkml.kernel.org/r/1594389708-60781-5-git-send-email-feng.tang@intel.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-06 23:23:15 -07:00
mm: hugetlb: skip initialization of gigantic tail struct pages if freed by HVO The new boot flow when it comes to initialization of gigantic pages is as follows: - At boot time, for a gigantic page during __alloc_bootmem_hugepage, the region after the first struct page is marked as noinit. - This results in only the first struct page to be initialized in reserve_bootmem_region. As the tail struct pages are not initialized at this point, there can be a significant saving in boot time if HVO succeeds later on. - Later on in the boot, the head page is prepped and the first HUGETLB_VMEMMAP_RESERVE_SIZE / sizeof(struct page) - 1 tail struct pages are initialized. - HVO is attempted. If it is not successful, then the rest of the tail struct pages are initialized. If it is successful, no more tail struct pages need to be initialized saving significant boot time. The WARN_ON for increased ref count in gather_bootmem_prealloc was changed to a VM_BUG_ON. This is OK as there should be no speculative references this early in boot process. The VM_BUG_ON's are there just in case such code is introduced. [akpm@linux-foundation.org: make it nicer for 80 cols] Link: https://lkml.kernel.org/r/20230913105401.519709-5-usama.arif@bytedance.com Signed-off-by: Usama Arif <usama.arif@bytedance.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Fam Zheng <fam.zheng@bytedance.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Punit Agrawal <punit.agrawal@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-13 11:54:01 +01:00
mm/mm_init: fix pageblock migratetype for ZONE_DEVICE compound pages The memmap_init_zone_device() function only initializes the migratetype of the first pageblock of a compound page. If the compound page size exceeds pageblock_nr_pages (e.g., 1GB hugepages with 2MB pageblocks), subsequent pageblocks in the compound page remain uninitialized. Move the migratetype initialization out of __init_zone_device_page() and into a separate pageblock_migratetype_init_range() function. This iterates over the entire PFN range of the memory, ensuring that all pageblocks are correctly initialized. Also remove the stale confusing comment about MEMINIT_HOTPLUG above the migratetype setting since it is an obsolete relic from commit 966cf44f637e ("mm: defer ZONE_DEVICE page initialization to the point where we init pgmap") and no longer makes sense here. Link: https://lore.kernel.org/20260428081855.1249045-6-songmuchun@bytedance.com Fixes: c4386bd8ee3a ("mm/memremap: add ZONE_DEVICE support for compound pages") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <liam@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-28 16:18:54 +08:00
mm/mm_init: fix pageblock migratetype for ZONE_DEVICE compound pages The memmap_init_zone_device() function only initializes the migratetype of the first pageblock of a compound page. If the compound page size exceeds pageblock_nr_pages (e.g., 1GB hugepages with 2MB pageblocks), subsequent pageblocks in the compound page remain uninitialized. Move the migratetype initialization out of __init_zone_device_page() and into a separate pageblock_migratetype_init_range() function. This iterates over the entire PFN range of the memory, ensuring that all pageblocks are correctly initialized. Also remove the stale confusing comment about MEMINIT_HOTPLUG above the migratetype setting since it is an obsolete relic from commit 966cf44f637e ("mm: defer ZONE_DEVICE page initialization to the point where we init pgmap") and no longer makes sense here. Link: https://lore.kernel.org/20260428081855.1249045-6-songmuchun@bytedance.com Fixes: c4386bd8ee3a ("mm/memremap: add ZONE_DEVICE support for compound pages") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <liam@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-28 16:18:54 +08:00
mm/mm_init: fix pageblock migratetype for ZONE_DEVICE compound pages The memmap_init_zone_device() function only initializes the migratetype of the first pageblock of a compound page. If the compound page size exceeds pageblock_nr_pages (e.g., 1GB hugepages with 2MB pageblocks), subsequent pageblocks in the compound page remain uninitialized. Move the migratetype initialization out of __init_zone_device_page() and into a separate pageblock_migratetype_init_range() function. This iterates over the entire PFN range of the memory, ensuring that all pageblocks are correctly initialized. Also remove the stale confusing comment about MEMINIT_HOTPLUG above the migratetype setting since it is an obsolete relic from commit 966cf44f637e ("mm: defer ZONE_DEVICE page initialization to the point where we init pgmap") and no longer makes sense here. Link: https://lore.kernel.org/20260428081855.1249045-6-songmuchun@bytedance.com Fixes: c4386bd8ee3a ("mm/memremap: add ZONE_DEVICE support for compound pages") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <liam@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-28 16:18:54 +08:00
memblock: introduce memmap_init_kho_scratch() With deferred initialization of struct page it will be necessary to initialize memory map for KHO scratch regions early. Add memmap_init_kho_scratch() method that will allow such initialization in upcoming patches. Link: https://lkml.kernel.org/r/20250509074635.3187114-4-changyuanl@google.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Changyuan Lyu <changyuanl@google.com> Cc: Alexander Graf <graf@amazon.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anthony Yznaga <anthony.yznaga@oracle.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ashish Kalra <ashish.kalra@amd.com> Cc: Ben Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Gowans <jgowans@amazon.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Pratyush Yadav <ptyadav@amazon.de> Cc: Rob Herring <robh@kernel.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Lendacky <thomas.lendacky@amd.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-09 00:46:21 -07:00
memblock: introduce memmap_init_kho_scratch() With deferred initialization of struct page it will be necessary to initialize memory map for KHO scratch regions early. Add memmap_init_kho_scratch() method that will allow such initialization in upcoming patches. Link: https://lkml.kernel.org/r/20250509074635.3187114-4-changyuanl@google.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Changyuan Lyu <changyuanl@google.com> Cc: Alexander Graf <graf@amazon.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anthony Yznaga <anthony.yznaga@oracle.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ashish Kalra <ashish.kalra@amd.com> Cc: Ben Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Gowans <jgowans@amazon.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Pratyush Yadav <ptyadav@amazon.de> Cc: Rob Herring <robh@kernel.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Lendacky <thomas.lendacky@amd.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-09 00:46:21 -07:00
memblock: introduce memmap_init_kho_scratch() With deferred initialization of struct page it will be necessary to initialize memory map for KHO scratch regions early. Add memmap_init_kho_scratch() method that will allow such initialization in upcoming patches. Link: https://lkml.kernel.org/r/20250509074635.3187114-4-changyuanl@google.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Changyuan Lyu <changyuanl@google.com> Cc: Alexander Graf <graf@amazon.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anthony Yznaga <anthony.yznaga@oracle.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ashish Kalra <ashish.kalra@amd.com> Cc: Ben Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Gowans <jgowans@amazon.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Pratyush Yadav <ptyadav@amazon.de> Cc: Rob Herring <robh@kernel.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Lendacky <thomas.lendacky@amd.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-09 00:46:21 -07:00
mm/memory_hotplug: initialize memmap of !ZONE_DEVICE with PageOffline() instead of PageReserved() We currently initialize the memmap such that PG_reserved is set and the refcount of the page is 1. In virtio-mem code, we have to manually clear that PG_reserved flag to make memory offlining with partially hotplugged memory blocks possible: has_unmovable_pages() would otherwise bail out on such pages. We want to avoid PG_reserved where possible and move to typed pages instead. Further, we want to further enlighten memory offlining code about PG_offline: offline pages in an online memory section. One example is handling managed page count adjustments in a cleaner way during memory offlining. So let's initialize the pages with PG_offline instead of PG_reserved. generic_online_page()->__free_pages_core() will now clear that flag before handing that memory to the buddy. Note that the page refcount is still 1 and would forbid offlining of such memory except when special care is take during GOING_OFFLINE as currently only implemented by virtio-mem. With this change, we can now get non-PageReserved() pages in the XEN balloon list. From what I can tell, that can already happen via decrease_reservation(), so that should be fine. HV-balloon should not really observe a change: partial online memory blocks still cannot get surprise-offlined, because the refcount of these PageOffline() pages is 1. Update virtio-mem, HV-balloon and XEN-balloon code to be aware that hotplugged pages are now PageOffline() instead of PageReserved() before they are handed over to the buddy. We'll leave the ZONE_DEVICE case alone for now. Note that self-hosted vmemmap pages will no longer be marked as reserved. This matches ordinary vmemmap pages allocated from the buddy during memory hotplug. Now, really only vmemmap pages allocated from memblock during early boot will be marked reserved. Existing PageReserved() checks seem to be handling all relevant cases correctly even after this change. Link: https://lkml.kernel.org/r/20240607090939.89524-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Acked-by: Oscar Salvador <osalvador@suse.de> [generic memory-hotplug bits] Cc: Alexander Potapenko <glider@google.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eugenio Pérez <eperezma@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Marco Elver <elver@google.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Wei Liu <wei.liu@kernel.org> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-07 11:09:37 +02:00
mm/mm_init: init holes in the end of the memory map for FLATMEM Patch series "mm: fixes for fallouts from mem_init() cleanup". These are the fixes for fallouts from mem_init() cleanup reported by Nathan Chancellor and kbuild. The details are in the commit messages. This patch (of 2): Kernel test robot reports the following crash on 32-bit system with FLATMEM and DEBUG_VM_PGFLAGS enabled: [ 0.478822][ T0] kernel BUG at include/linux/page-flags.h:536! [ 0.479312][ T0] Oops: invalid opcode: 0000 [#1] PREEMPT SMP [ 0.479768][ T0] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.14.0-rc6-00357-g8268af309d07 #1 [ 0.480470][ T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 0.481260][ T0] EIP: reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.481683][ T0] Code: 5d c3 01 f1 89 c8 ba e1 38 f4 c3 e8 1e 37 8e fc 0f 0b b8 90 e2 62 c4 e8 e2 05 5e fc 01 f1 89 c8 ba be 85 f7 c3 e8 04 37 8e fc <0f> 0b b8 80 e2 62 c4 e8 c8 05 5e fc 55 89 e5 53 57 56 83 ec 10 89 [ 0.483177][ T0] EAX: 00000000 EBX: c425df50 ECX: 00000000 EDX: 00000000 [ 0.483712][ T0] ESI: 017ffc00 EDI: ffffffff EBP: c425df34 ESP: c425df2c [ 0.484248][ T0] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00210046 [ 0.484846][ T0] CR0: 80050033 CR2: 00000000 CR3: 04b48000 CR4: 00000090 [ 0.485376][ T0] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 0.485907][ T0] DR6: fffe0ff0 DR7: 00000400 [ 0.486253][ T0] Call Trace: [ 0.486494][ T0] ? __die_body (arch/x86/kernel/dumpstack.c:478) [ 0.486822][ T0] ? die (arch/x86/kernel/dumpstack.c:?) [ 0.487099][ T0] ? do_trap (arch/x86/kernel/traps.c:? arch/x86/kernel/traps.c:197) [ 0.487409][ T0] ? do_error_trap (arch/x86/kernel/traps.c:217) [ 0.487752][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.488153][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.488490][ T0] ? handle_invalid_op (arch/x86/kernel/traps.c:254) [ 0.488869][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.489271][ T0] ? exc_invalid_op (arch/x86/kernel/traps.c:316) [ 0.489619][ T0] ? handle_exception (arch/x86/entry/entry_32.S:1055) [ 0.489996][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.490332][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.490733][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.491068][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.491470][ T0] memmap_init_reserved_pages (mm/memblock.c:2203) [ 0.491887][ T0] free_low_memory_core_early (mm/memblock.c:?) [ 0.492302][ T0] memblock_free_all (mm/memblock.c:2272 include/linux/atomic/atomic-arch-fallback.h:546 include/linux/atomic/atomic-long.h:123 include/linux/atomic/atomic-instrumented.h:3261 include/linux/mm.h:67 mm/memblock.c:2273) [ 0.492659][ T0] mem_init (arch/x86/mm/init_32.c:735) [ 0.492952][ T0] mm_core_init (mm/mm_init.c:2730) [ 0.493271][ T0] start_kernel (init/main.c:958) [ 0.493604][ T0] i386_start_kernel (arch/x86/kernel/head32.c:79) [ 0.493969][ T0] startup_32_smp (arch/x86/kernel/head_32.S:292) The crash happens because after commit 8268af309d07 ("arch, mm: set max_mapnr when allocating memory map for FLATMEM") max_mapnr is rounded up to MAX_ORDER_NR_PAGES and the pages in the end of the memory map are passing pfn_valid() check in reserve_bootmem_region(). Make sure that that pages in the end of the memory map are initialized, just like the pages in the end of the last section for SPARSEMEM. Link: https://lkml.kernel.org/r/20250325114928.1791109-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20250325114928.1791109-2-rppt@kernel.org Fixes: 8268af309d07 ("arch, mm: set max_mapnr when allocating memory map for FLATMEM") Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202503241424.d16223ec-lkp@intel.com Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-25 13:49:27 +02:00
mm/mm_init: init holes in the end of the memory map for FLATMEM Patch series "mm: fixes for fallouts from mem_init() cleanup". These are the fixes for fallouts from mem_init() cleanup reported by Nathan Chancellor and kbuild. The details are in the commit messages. This patch (of 2): Kernel test robot reports the following crash on 32-bit system with FLATMEM and DEBUG_VM_PGFLAGS enabled: [ 0.478822][ T0] kernel BUG at include/linux/page-flags.h:536! [ 0.479312][ T0] Oops: invalid opcode: 0000 [#1] PREEMPT SMP [ 0.479768][ T0] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.14.0-rc6-00357-g8268af309d07 #1 [ 0.480470][ T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 0.481260][ T0] EIP: reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.481683][ T0] Code: 5d c3 01 f1 89 c8 ba e1 38 f4 c3 e8 1e 37 8e fc 0f 0b b8 90 e2 62 c4 e8 e2 05 5e fc 01 f1 89 c8 ba be 85 f7 c3 e8 04 37 8e fc <0f> 0b b8 80 e2 62 c4 e8 c8 05 5e fc 55 89 e5 53 57 56 83 ec 10 89 [ 0.483177][ T0] EAX: 00000000 EBX: c425df50 ECX: 00000000 EDX: 00000000 [ 0.483712][ T0] ESI: 017ffc00 EDI: ffffffff EBP: c425df34 ESP: c425df2c [ 0.484248][ T0] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00210046 [ 0.484846][ T0] CR0: 80050033 CR2: 00000000 CR3: 04b48000 CR4: 00000090 [ 0.485376][ T0] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 0.485907][ T0] DR6: fffe0ff0 DR7: 00000400 [ 0.486253][ T0] Call Trace: [ 0.486494][ T0] ? __die_body (arch/x86/kernel/dumpstack.c:478) [ 0.486822][ T0] ? die (arch/x86/kernel/dumpstack.c:?) [ 0.487099][ T0] ? do_trap (arch/x86/kernel/traps.c:? arch/x86/kernel/traps.c:197) [ 0.487409][ T0] ? do_error_trap (arch/x86/kernel/traps.c:217) [ 0.487752][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.488153][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.488490][ T0] ? handle_invalid_op (arch/x86/kernel/traps.c:254) [ 0.488869][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.489271][ T0] ? exc_invalid_op (arch/x86/kernel/traps.c:316) [ 0.489619][ T0] ? handle_exception (arch/x86/entry/entry_32.S:1055) [ 0.489996][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.490332][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.490733][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.491068][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.491470][ T0] memmap_init_reserved_pages (mm/memblock.c:2203) [ 0.491887][ T0] free_low_memory_core_early (mm/memblock.c:?) [ 0.492302][ T0] memblock_free_all (mm/memblock.c:2272 include/linux/atomic/atomic-arch-fallback.h:546 include/linux/atomic/atomic-long.h:123 include/linux/atomic/atomic-instrumented.h:3261 include/linux/mm.h:67 mm/memblock.c:2273) [ 0.492659][ T0] mem_init (arch/x86/mm/init_32.c:735) [ 0.492952][ T0] mm_core_init (mm/mm_init.c:2730) [ 0.493271][ T0] start_kernel (init/main.c:958) [ 0.493604][ T0] i386_start_kernel (arch/x86/kernel/head32.c:79) [ 0.493969][ T0] startup_32_smp (arch/x86/kernel/head_32.S:292) The crash happens because after commit 8268af309d07 ("arch, mm: set max_mapnr when allocating memory map for FLATMEM") max_mapnr is rounded up to MAX_ORDER_NR_PAGES and the pages in the end of the memory map are passing pfn_valid() check in reserve_bootmem_region(). Make sure that that pages in the end of the memory map are initialized, just like the pages in the end of the last section for SPARSEMEM. Link: https://lkml.kernel.org/r/20250325114928.1791109-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20250325114928.1791109-2-rppt@kernel.org Fixes: 8268af309d07 ("arch, mm: set max_mapnr when allocating memory map for FLATMEM") Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202503241424.d16223ec-lkp@intel.com Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-25 13:49:27 +02:00
mm/mm_init: init holes in the end of the memory map for FLATMEM Patch series "mm: fixes for fallouts from mem_init() cleanup". These are the fixes for fallouts from mem_init() cleanup reported by Nathan Chancellor and kbuild. The details are in the commit messages. This patch (of 2): Kernel test robot reports the following crash on 32-bit system with FLATMEM and DEBUG_VM_PGFLAGS enabled: [ 0.478822][ T0] kernel BUG at include/linux/page-flags.h:536! [ 0.479312][ T0] Oops: invalid opcode: 0000 [#1] PREEMPT SMP [ 0.479768][ T0] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.14.0-rc6-00357-g8268af309d07 #1 [ 0.480470][ T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 0.481260][ T0] EIP: reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.481683][ T0] Code: 5d c3 01 f1 89 c8 ba e1 38 f4 c3 e8 1e 37 8e fc 0f 0b b8 90 e2 62 c4 e8 e2 05 5e fc 01 f1 89 c8 ba be 85 f7 c3 e8 04 37 8e fc <0f> 0b b8 80 e2 62 c4 e8 c8 05 5e fc 55 89 e5 53 57 56 83 ec 10 89 [ 0.483177][ T0] EAX: 00000000 EBX: c425df50 ECX: 00000000 EDX: 00000000 [ 0.483712][ T0] ESI: 017ffc00 EDI: ffffffff EBP: c425df34 ESP: c425df2c [ 0.484248][ T0] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00210046 [ 0.484846][ T0] CR0: 80050033 CR2: 00000000 CR3: 04b48000 CR4: 00000090 [ 0.485376][ T0] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 0.485907][ T0] DR6: fffe0ff0 DR7: 00000400 [ 0.486253][ T0] Call Trace: [ 0.486494][ T0] ? __die_body (arch/x86/kernel/dumpstack.c:478) [ 0.486822][ T0] ? die (arch/x86/kernel/dumpstack.c:?) [ 0.487099][ T0] ? do_trap (arch/x86/kernel/traps.c:? arch/x86/kernel/traps.c:197) [ 0.487409][ T0] ? do_error_trap (arch/x86/kernel/traps.c:217) [ 0.487752][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.488153][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.488490][ T0] ? handle_invalid_op (arch/x86/kernel/traps.c:254) [ 0.488869][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.489271][ T0] ? exc_invalid_op (arch/x86/kernel/traps.c:316) [ 0.489619][ T0] ? handle_exception (arch/x86/entry/entry_32.S:1055) [ 0.489996][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.490332][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.490733][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.491068][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.491470][ T0] memmap_init_reserved_pages (mm/memblock.c:2203) [ 0.491887][ T0] free_low_memory_core_early (mm/memblock.c:?) [ 0.492302][ T0] memblock_free_all (mm/memblock.c:2272 include/linux/atomic/atomic-arch-fallback.h:546 include/linux/atomic/atomic-long.h:123 include/linux/atomic/atomic-instrumented.h:3261 include/linux/mm.h:67 mm/memblock.c:2273) [ 0.492659][ T0] mem_init (arch/x86/mm/init_32.c:735) [ 0.492952][ T0] mm_core_init (mm/mm_init.c:2730) [ 0.493271][ T0] start_kernel (init/main.c:958) [ 0.493604][ T0] i386_start_kernel (arch/x86/kernel/head32.c:79) [ 0.493969][ T0] startup_32_smp (arch/x86/kernel/head_32.S:292) The crash happens because after commit 8268af309d07 ("arch, mm: set max_mapnr when allocating memory map for FLATMEM") max_mapnr is rounded up to MAX_ORDER_NR_PAGES and the pages in the end of the memory map are passing pfn_valid() check in reserve_bootmem_region(). Make sure that that pages in the end of the memory map are initialized, just like the pages in the end of the last section for SPARSEMEM. Link: https://lkml.kernel.org/r/20250325114928.1791109-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20250325114928.1791109-2-rppt@kernel.org Fixes: 8268af309d07 ("arch, mm: set max_mapnr when allocating memory map for FLATMEM") Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202503241424.d16223ec-lkp@intel.com Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-25 13:49:27 +02:00
mm/mm_init: init holes in the end of the memory map for FLATMEM Patch series "mm: fixes for fallouts from mem_init() cleanup". These are the fixes for fallouts from mem_init() cleanup reported by Nathan Chancellor and kbuild. The details are in the commit messages. This patch (of 2): Kernel test robot reports the following crash on 32-bit system with FLATMEM and DEBUG_VM_PGFLAGS enabled: [ 0.478822][ T0] kernel BUG at include/linux/page-flags.h:536! [ 0.479312][ T0] Oops: invalid opcode: 0000 [#1] PREEMPT SMP [ 0.479768][ T0] CPU: 0 UID: 0 PID: 0 Comm: swapper Not tainted 6.14.0-rc6-00357-g8268af309d07 #1 [ 0.480470][ T0] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 [ 0.481260][ T0] EIP: reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.481683][ T0] Code: 5d c3 01 f1 89 c8 ba e1 38 f4 c3 e8 1e 37 8e fc 0f 0b b8 90 e2 62 c4 e8 e2 05 5e fc 01 f1 89 c8 ba be 85 f7 c3 e8 04 37 8e fc <0f> 0b b8 80 e2 62 c4 e8 c8 05 5e fc 55 89 e5 53 57 56 83 ec 10 89 [ 0.483177][ T0] EAX: 00000000 EBX: c425df50 ECX: 00000000 EDX: 00000000 [ 0.483712][ T0] ESI: 017ffc00 EDI: ffffffff EBP: c425df34 ESP: c425df2c [ 0.484248][ T0] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068 EFLAGS: 00210046 [ 0.484846][ T0] CR0: 80050033 CR2: 00000000 CR3: 04b48000 CR4: 00000090 [ 0.485376][ T0] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000 [ 0.485907][ T0] DR6: fffe0ff0 DR7: 00000400 [ 0.486253][ T0] Call Trace: [ 0.486494][ T0] ? __die_body (arch/x86/kernel/dumpstack.c:478) [ 0.486822][ T0] ? die (arch/x86/kernel/dumpstack.c:?) [ 0.487099][ T0] ? do_trap (arch/x86/kernel/traps.c:? arch/x86/kernel/traps.c:197) [ 0.487409][ T0] ? do_error_trap (arch/x86/kernel/traps.c:217) [ 0.487752][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.488153][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.488490][ T0] ? handle_invalid_op (arch/x86/kernel/traps.c:254) [ 0.488869][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.489271][ T0] ? exc_invalid_op (arch/x86/kernel/traps.c:316) [ 0.489619][ T0] ? handle_exception (arch/x86/entry/entry_32.S:1055) [ 0.489996][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.490332][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.490733][ T0] ? exc_overflow (arch/x86/kernel/traps.c:301) [ 0.491068][ T0] ? reserve_bootmem_region (include/linux/page-flags.h:536) [ 0.491470][ T0] memmap_init_reserved_pages (mm/memblock.c:2203) [ 0.491887][ T0] free_low_memory_core_early (mm/memblock.c:?) [ 0.492302][ T0] memblock_free_all (mm/memblock.c:2272 include/linux/atomic/atomic-arch-fallback.h:546 include/linux/atomic/atomic-long.h:123 include/linux/atomic/atomic-instrumented.h:3261 include/linux/mm.h:67 mm/memblock.c:2273) [ 0.492659][ T0] mem_init (arch/x86/mm/init_32.c:735) [ 0.492952][ T0] mm_core_init (mm/mm_init.c:2730) [ 0.493271][ T0] start_kernel (init/main.c:958) [ 0.493604][ T0] i386_start_kernel (arch/x86/kernel/head32.c:79) [ 0.493969][ T0] startup_32_smp (arch/x86/kernel/head_32.S:292) The crash happens because after commit 8268af309d07 ("arch, mm: set max_mapnr when allocating memory map for FLATMEM") max_mapnr is rounded up to MAX_ORDER_NR_PAGES and the pages in the end of the memory map are passing pfn_valid() check in reserve_bootmem_region(). Make sure that that pages in the end of the memory map are initialized, just like the pages in the end of the last section for SPARSEMEM. Link: https://lkml.kernel.org/r/20250325114928.1791109-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20250325114928.1791109-2-rppt@kernel.org Fixes: 8268af309d07 ("arch, mm: set max_mapnr when allocating memory map for FLATMEM") Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202503241424.d16223ec-lkp@intel.com Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-25 13:49:27 +02:00
mm: allow compound zone device pages Zone device pages are used to represent various type of device memory managed by device drivers. Currently compound zone device pages are not supported. This is because MEMORY_DEVICE_FS_DAX pages are the only user of higher order zone device pages and have their own page reference counting. A future change will unify FS DAX reference counting with normal page reference counting rules and remove the special FS DAX reference counting. Supporting that requires compound zone device pages. Supporting compound zone device pages requires compound_head() to distinguish between head and tail pages whilst still preserving the special struct page fields that are specific to zone device pages. A tail page is distinguished by having bit zero being set in page->compound_head, with the remaining bits pointing to the head page. For zone device pages page->compound_head is shared with page->pgmap. The page->pgmap field must be common to all pages within a folio, even if the folio spans memory sections. Therefore pgmap is the same for both head and tail pages and can be moved into the folio and we can use the standard scheme to find compound_head from a tail page. Link: https://lkml.kernel.org/r/67055d772e6102accf85161d0b57b0b3944292bf.1740713401.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Signed-off-by: Balbir Singh <balbirs@nvidia.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Alison Schofield <alison.schofield@intel.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Asahi Lina <lina@asahilina.net> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: linmiaohe <linmiaohe@huawei.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Ted Ts'o <tytso@mit.edu> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-28 14:31:06 +11:00
fs/dax: properly refcount fs dax pages Currently fs dax pages are considered free when the refcount drops to one and their refcounts are not increased when mapped via PTEs or decreased when unmapped. This requires special logic in mm paths to detect that these pages should not be properly refcounted, and to detect when the refcount drops to one instead of zero. On the other hand get_user_pages(), etc. will properly refcount fs dax pages by taking a reference and dropping it when the page is unpinned. Tracking this special behaviour requires extra PTE bits (eg. pte_devmap) and introduces rules that are potentially confusing and specific to FS DAX pages. To fix this, and to possibly allow removal of the special PTE bits in future, convert the fs dax page refcounts to be zero based and instead take a reference on the page each time it is mapped as is currently the case for normal pages. This may also allow a future clean-up to remove the pgmap refcounting that is currently done in mm/gup.c. Link: https://lkml.kernel.org/r/c7d886ad7468a20452ef6e0ddab6cfe220874e7c.1740713401.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Alison Schofield <alison.schofield@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Asahi Lina <lina@asahilina.net> Cc: Balbir Singh <balbirs@nvidia.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: linmiaohe <linmiaohe@huawei.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Ted Ts'o <tytso@mit.edu> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-28 14:31:14 +11:00
mm/mm_init: move p2pdma page refcount initialisation to p2pdma Currently ZONE_DEVICE page reference counts are initialised by core memory management code in __init_zone_device_page() as part of the memremap() call which driver modules make to obtain ZONE_DEVICE pages. This initialises page refcounts to 1 before returning them to the driver. This was presumably done because it drivers had a reference of sorts on the page. It also ensured the page could always be mapped with vm_insert_page() for example and would never get freed (ie. have a zero refcount), freeing drivers of manipulating page reference counts. However it complicates figuring out whether or not a page is free from the mm perspective because it is no longer possible to just look at the refcount. Instead the page type must be known and if GUP is used a secondary pgmap reference is also sometimes needed. To simplify this it is desirable to remove the page reference count for the driver, so core mm can just use the refcount without having to account for page type or do other types of tracking. This is possible because drivers can always assume the page is valid as core kernel will never offline or remove the struct page. This means it is now up to drivers to initialise the page refcount as required. P2PDMA uses vm_insert_page() to map the page, and that requires a non-zero reference count when initialising the page so set that when the page is first mapped. Link: https://lkml.kernel.org/r/6aedb0ac2886dcc4503cb705273db5b3863a0b66.1740713401.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Alison Schofield <alison.schofield@intel.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Asahi Lina <lina@asahilina.net> Cc: Balbir Singh <balbirs@nvidia.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: linmiaohe <linmiaohe@huawei.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Ted Ts'o <tytso@mit.edu> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-28 14:31:05 +11:00
mm/mm_init: move p2pdma page refcount initialisation to p2pdma Currently ZONE_DEVICE page reference counts are initialised by core memory management code in __init_zone_device_page() as part of the memremap() call which driver modules make to obtain ZONE_DEVICE pages. This initialises page refcounts to 1 before returning them to the driver. This was presumably done because it drivers had a reference of sorts on the page. It also ensured the page could always be mapped with vm_insert_page() for example and would never get freed (ie. have a zero refcount), freeing drivers of manipulating page reference counts. However it complicates figuring out whether or not a page is free from the mm perspective because it is no longer possible to just look at the refcount. Instead the page type must be known and if GUP is used a secondary pgmap reference is also sometimes needed. To simplify this it is desirable to remove the page reference count for the driver, so core mm can just use the refcount without having to account for page type or do other types of tracking. This is possible because drivers can always assume the page is valid as core kernel will never offline or remove the struct page. This means it is now up to drivers to initialise the page refcount as required. P2PDMA uses vm_insert_page() to map the page, and that requires a non-zero reference count when initialising the page so set that when the page is first mapped. Link: https://lkml.kernel.org/r/6aedb0ac2886dcc4503cb705273db5b3863a0b66.1740713401.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Alison Schofield <alison.schofield@intel.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Asahi Lina <lina@asahilina.net> Cc: Balbir Singh <balbirs@nvidia.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: linmiaohe <linmiaohe@huawei.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Ted Ts'o <tytso@mit.edu> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-28 14:31:05 +11:00
fs/dax: properly refcount fs dax pages Currently fs dax pages are considered free when the refcount drops to one and their refcounts are not increased when mapped via PTEs or decreased when unmapped. This requires special logic in mm paths to detect that these pages should not be properly refcounted, and to detect when the refcount drops to one instead of zero. On the other hand get_user_pages(), etc. will properly refcount fs dax pages by taking a reference and dropping it when the page is unpinned. Tracking this special behaviour requires extra PTE bits (eg. pte_devmap) and introduces rules that are potentially confusing and specific to FS DAX pages. To fix this, and to possibly allow removal of the special PTE bits in future, convert the fs dax page refcounts to be zero based and instead take a reference on the page each time it is mapped as is currently the case for normal pages. This may also allow a future clean-up to remove the pgmap refcounting that is currently done in mm/gup.c. Link: https://lkml.kernel.org/r/c7d886ad7468a20452ef6e0ddab6cfe220874e7c.1740713401.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Alison Schofield <alison.schofield@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Asahi Lina <lina@asahilina.net> Cc: Balbir Singh <balbirs@nvidia.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: linmiaohe <linmiaohe@huawei.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Ted Ts'o <tytso@mit.edu> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-28 14:31:14 +11:00
mm/mm_init: move p2pdma page refcount initialisation to p2pdma Currently ZONE_DEVICE page reference counts are initialised by core memory management code in __init_zone_device_page() as part of the memremap() call which driver modules make to obtain ZONE_DEVICE pages. This initialises page refcounts to 1 before returning them to the driver. This was presumably done because it drivers had a reference of sorts on the page. It also ensured the page could always be mapped with vm_insert_page() for example and would never get freed (ie. have a zero refcount), freeing drivers of manipulating page reference counts. However it complicates figuring out whether or not a page is free from the mm perspective because it is no longer possible to just look at the refcount. Instead the page type must be known and if GUP is used a secondary pgmap reference is also sometimes needed. To simplify this it is desirable to remove the page reference count for the driver, so core mm can just use the refcount without having to account for page type or do other types of tracking. This is possible because drivers can always assume the page is valid as core kernel will never offline or remove the struct page. This means it is now up to drivers to initialise the page refcount as required. P2PDMA uses vm_insert_page() to map the page, and that requires a non-zero reference count when initialising the page so set that when the page is first mapped. Link: https://lkml.kernel.org/r/6aedb0ac2886dcc4503cb705273db5b3863a0b66.1740713401.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Alison Schofield <alison.schofield@intel.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Asahi Lina <lina@asahilina.net> Cc: Balbir Singh <balbirs@nvidia.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: linmiaohe <linmiaohe@huawei.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Ted Ts'o <tytso@mit.edu> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-28 14:31:05 +11:00
mm/mm_init: move p2pdma page refcount initialisation to p2pdma Currently ZONE_DEVICE page reference counts are initialised by core memory management code in __init_zone_device_page() as part of the memremap() call which driver modules make to obtain ZONE_DEVICE pages. This initialises page refcounts to 1 before returning them to the driver. This was presumably done because it drivers had a reference of sorts on the page. It also ensured the page could always be mapped with vm_insert_page() for example and would never get freed (ie. have a zero refcount), freeing drivers of manipulating page reference counts. However it complicates figuring out whether or not a page is free from the mm perspective because it is no longer possible to just look at the refcount. Instead the page type must be known and if GUP is used a secondary pgmap reference is also sometimes needed. To simplify this it is desirable to remove the page reference count for the driver, so core mm can just use the refcount without having to account for page type or do other types of tracking. This is possible because drivers can always assume the page is valid as core kernel will never offline or remove the struct page. This means it is now up to drivers to initialise the page refcount as required. P2PDMA uses vm_insert_page() to map the page, and that requires a non-zero reference count when initialising the page so set that when the page is first mapped. Link: https://lkml.kernel.org/r/6aedb0ac2886dcc4503cb705273db5b3863a0b66.1740713401.git-series.apopple@nvidia.com Signed-off-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Dan Williams <dan.j.williams@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Alison Schofield <alison.schofield@intel.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Asahi Lina <lina@asahilina.net> Cc: Balbir Singh <balbirs@nvidia.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Chunyan Zhang <zhang.lyra@gmail.com> Cc: "Darrick J. Wong" <djwong@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: John Hubbard <jhubbard@nvidia.com> Cc: linmiaohe <linmiaohe@huawei.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Matthew Wilcow (Oracle) <willy@infradead.org> Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Ted Ts'o <tytso@mit.edu> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vishal Verma <vishal.l.verma@intel.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-28 14:31:05 +11:00
mm/vmemmap/devdax: fix kernel crash when probing devdax devices commit 4917f55b4ef9 ("mm/sparse-vmemmap: improve memory savings for compound devmaps") added support for using optimized vmmemap for devdax devices. But how vmemmap mappings are created are architecture specific. For example, powerpc with hash translation doesn't have vmemmap mappings in init_mm page table instead they are bolted table entries in the hardware page table vmemmap_populate_compound_pages() used by vmemmap optimization code is not aware of these architecture-specific mapping. Hence allow architecture to opt for this feature. I selected architectures supporting HUGETLB_PAGE_OPTIMIZE_VMEMMAP option as also supporting this feature. This patch fixes the below crash on ppc64. BUG: Unable to handle kernel data access on write at 0xc00c000100400038 Faulting instruction address: 0xc000000001269d90 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 7 PID: 1 Comm: swapper/0 Not tainted 6.3.0-rc5-150500.34-default+ #2 5c90a668b6bbd142599890245c2fb5de19d7d28a Hardware name: IBM,9009-42G POWER9 (raw) 0x4e0202 0xf000005 of:IBM,FW950.40 (VL950_099) hv:phyp pSeries NIP: c000000001269d90 LR: c0000000004c57d4 CTR: 0000000000000000 REGS: c000000003632c30 TRAP: 0300 Not tainted (6.3.0-rc5-150500.34-default+) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 24842228 XER: 00000000 CFAR: c0000000004c57d0 DAR: c00c000100400038 DSISR: 42000000 IRQMASK: 0 .... NIP [c000000001269d90] __init_single_page.isra.74+0x14/0x4c LR [c0000000004c57d4] __init_zone_device_page+0x44/0xd0 Call Trace: [c000000003632ed0] [c000000003632f60] 0xc000000003632f60 (unreliable) [c000000003632f10] [c0000000004c5ca0] memmap_init_zone_device+0x170/0x250 [c000000003632fe0] [c0000000005575f8] memremap_pages+0x2c8/0x7f0 [c0000000036330c0] [c000000000557b5c] devm_memremap_pages+0x3c/0xa0 [c000000003633100] [c000000000d458a8] dev_dax_probe+0x108/0x3e0 [c0000000036331a0] [c000000000d41430] dax_bus_probe+0xb0/0x140 [c0000000036331d0] [c000000000cef27c] really_probe+0x19c/0x520 [c000000003633260] [c000000000cef6b4] __driver_probe_device+0xb4/0x230 [c0000000036332e0] [c000000000cef888] driver_probe_device+0x58/0x120 [c000000003633320] [c000000000cefa6c] __device_attach_driver+0x11c/0x1e0 [c0000000036333a0] [c000000000cebc58] bus_for_each_drv+0xa8/0x130 [c000000003633400] [c000000000ceefcc] __device_attach+0x15c/0x250 [c0000000036334a0] [c000000000ced458] bus_probe_device+0x108/0x110 [c0000000036334f0] [c000000000ce92dc] device_add+0x7fc/0xa10 [c0000000036335b0] [c000000000d447c8] devm_create_dev_dax+0x1d8/0x530 [c000000003633640] [c000000000d46b60] __dax_pmem_probe+0x200/0x270 [c0000000036337b0] [c000000000d46bf0] dax_pmem_probe+0x20/0x70 [c0000000036337d0] [c000000000d2279c] nvdimm_bus_probe+0xac/0x2b0 [c000000003633860] [c000000000cef27c] really_probe+0x19c/0x520 [c0000000036338f0] [c000000000cef6b4] __driver_probe_device+0xb4/0x230 [c000000003633970] [c000000000cef888] driver_probe_device+0x58/0x120 [c0000000036339b0] [c000000000cefd08] __driver_attach+0x1d8/0x240 [c000000003633a30] [c000000000cebb04] bus_for_each_dev+0xb4/0x130 [c000000003633a90] [c000000000cee564] driver_attach+0x34/0x50 [c000000003633ab0] [c000000000ced878] bus_add_driver+0x218/0x300 [c000000003633b40] [c000000000cf1144] driver_register+0xa4/0x1b0 [c000000003633bb0] [c000000000d21a0c] __nd_driver_register+0x5c/0x100 [c000000003633c10] [c00000000206a2e8] dax_pmem_init+0x34/0x48 [c000000003633c30] [c0000000000132d0] do_one_initcall+0x60/0x320 [c000000003633d00] [c0000000020051b0] kernel_init_freeable+0x360/0x400 [c000000003633de0] [c000000000013764] kernel_init+0x34/0x1d0 [c000000003633e50] [c00000000000de14] ret_from_kernel_thread+0x5c/0x64 Link: https://lkml.kernel.org/r/20230411142214.64464-1-aneesh.kumar@linux.ibm.com Fixes: 4917f55b4ef9 ("mm/sparse-vmemmap: improve memory savings for compound devmaps") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reported-by: Tarun Sahu <tsahu@linux.ibm.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-11 19:52:13 +05:30
mm/vmemmap/devdax: fix kernel crash when probing devdax devices commit 4917f55b4ef9 ("mm/sparse-vmemmap: improve memory savings for compound devmaps") added support for using optimized vmmemap for devdax devices. But how vmemmap mappings are created are architecture specific. For example, powerpc with hash translation doesn't have vmemmap mappings in init_mm page table instead they are bolted table entries in the hardware page table vmemmap_populate_compound_pages() used by vmemmap optimization code is not aware of these architecture-specific mapping. Hence allow architecture to opt for this feature. I selected architectures supporting HUGETLB_PAGE_OPTIMIZE_VMEMMAP option as also supporting this feature. This patch fixes the below crash on ppc64. BUG: Unable to handle kernel data access on write at 0xc00c000100400038 Faulting instruction address: 0xc000000001269d90 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: CPU: 7 PID: 1 Comm: swapper/0 Not tainted 6.3.0-rc5-150500.34-default+ #2 5c90a668b6bbd142599890245c2fb5de19d7d28a Hardware name: IBM,9009-42G POWER9 (raw) 0x4e0202 0xf000005 of:IBM,FW950.40 (VL950_099) hv:phyp pSeries NIP: c000000001269d90 LR: c0000000004c57d4 CTR: 0000000000000000 REGS: c000000003632c30 TRAP: 0300 Not tainted (6.3.0-rc5-150500.34-default+) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 24842228 XER: 00000000 CFAR: c0000000004c57d0 DAR: c00c000100400038 DSISR: 42000000 IRQMASK: 0 .... NIP [c000000001269d90] __init_single_page.isra.74+0x14/0x4c LR [c0000000004c57d4] __init_zone_device_page+0x44/0xd0 Call Trace: [c000000003632ed0] [c000000003632f60] 0xc000000003632f60 (unreliable) [c000000003632f10] [c0000000004c5ca0] memmap_init_zone_device+0x170/0x250 [c000000003632fe0] [c0000000005575f8] memremap_pages+0x2c8/0x7f0 [c0000000036330c0] [c000000000557b5c] devm_memremap_pages+0x3c/0xa0 [c000000003633100] [c000000000d458a8] dev_dax_probe+0x108/0x3e0 [c0000000036331a0] [c000000000d41430] dax_bus_probe+0xb0/0x140 [c0000000036331d0] [c000000000cef27c] really_probe+0x19c/0x520 [c000000003633260] [c000000000cef6b4] __driver_probe_device+0xb4/0x230 [c0000000036332e0] [c000000000cef888] driver_probe_device+0x58/0x120 [c000000003633320] [c000000000cefa6c] __device_attach_driver+0x11c/0x1e0 [c0000000036333a0] [c000000000cebc58] bus_for_each_drv+0xa8/0x130 [c000000003633400] [c000000000ceefcc] __device_attach+0x15c/0x250 [c0000000036334a0] [c000000000ced458] bus_probe_device+0x108/0x110 [c0000000036334f0] [c000000000ce92dc] device_add+0x7fc/0xa10 [c0000000036335b0] [c000000000d447c8] devm_create_dev_dax+0x1d8/0x530 [c000000003633640] [c000000000d46b60] __dax_pmem_probe+0x200/0x270 [c0000000036337b0] [c000000000d46bf0] dax_pmem_probe+0x20/0x70 [c0000000036337d0] [c000000000d2279c] nvdimm_bus_probe+0xac/0x2b0 [c000000003633860] [c000000000cef27c] really_probe+0x19c/0x520 [c0000000036338f0] [c000000000cef6b4] __driver_probe_device+0xb4/0x230 [c000000003633970] [c000000000cef888] driver_probe_device+0x58/0x120 [c0000000036339b0] [c000000000cefd08] __driver_attach+0x1d8/0x240 [c000000003633a30] [c000000000cebb04] bus_for_each_dev+0xb4/0x130 [c000000003633a90] [c000000000cee564] driver_attach+0x34/0x50 [c000000003633ab0] [c000000000ced878] bus_add_driver+0x218/0x300 [c000000003633b40] [c000000000cf1144] driver_register+0xa4/0x1b0 [c000000003633bb0] [c000000000d21a0c] __nd_driver_register+0x5c/0x100 [c000000003633c10] [c00000000206a2e8] dax_pmem_init+0x34/0x48 [c000000003633c30] [c0000000000132d0] do_one_initcall+0x60/0x320 [c000000003633d00] [c0000000020051b0] kernel_init_freeable+0x360/0x400 [c000000003633de0] [c000000000013764] kernel_init+0x34/0x1d0 [c000000003633e50] [c00000000000de14] ret_from_kernel_thread+0x5c/0x64 Link: https://lkml.kernel.org/r/20230411142214.64464-1-aneesh.kumar@linux.ibm.com Fixes: 4917f55b4ef9 ("mm/sparse-vmemmap: improve memory savings for compound devmaps") Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reported-by: Tarun Sahu <tsahu@linux.ibm.com> Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-11 19:52:13 +05:30
mm/mm_init: fix pageblock migratetype for ZONE_DEVICE compound pages The memmap_init_zone_device() function only initializes the migratetype of the first pageblock of a compound page. If the compound page size exceeds pageblock_nr_pages (e.g., 1GB hugepages with 2MB pageblocks), subsequent pageblocks in the compound page remain uninitialized. Move the migratetype initialization out of __init_zone_device_page() and into a separate pageblock_migratetype_init_range() function. This iterates over the entire PFN range of the memory, ensuring that all pageblocks are correctly initialized. Also remove the stale confusing comment about MEMINIT_HOTPLUG above the migratetype setting since it is an obsolete relic from commit 966cf44f637e ("mm: defer ZONE_DEVICE page initialization to the point where we init pgmap") and no longer makes sense here. Link: https://lore.kernel.org/20260428081855.1249045-6-songmuchun@bytedance.com Fixes: c4386bd8ee3a ("mm/memremap: add ZONE_DEVICE support for compound pages") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <liam@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-28 16:18:54 +08:00
mm/mm_init: fix pageblock migratetype for ZONE_DEVICE compound pages The memmap_init_zone_device() function only initializes the migratetype of the first pageblock of a compound page. If the compound page size exceeds pageblock_nr_pages (e.g., 1GB hugepages with 2MB pageblocks), subsequent pageblocks in the compound page remain uninitialized. Move the migratetype initialization out of __init_zone_device_page() and into a separate pageblock_migratetype_init_range() function. This iterates over the entire PFN range of the memory, ensuring that all pageblocks are correctly initialized. Also remove the stale confusing comment about MEMINIT_HOTPLUG above the migratetype setting since it is an obsolete relic from commit 966cf44f637e ("mm: defer ZONE_DEVICE page initialization to the point where we init pgmap") and no longer makes sense here. Link: https://lore.kernel.org/20260428081855.1249045-6-songmuchun@bytedance.com Fixes: c4386bd8ee3a ("mm/memremap: add ZONE_DEVICE support for compound pages") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Oscar Salvador <osalvador@suse.de> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <liam@infradead.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-28 16:18:54 +08:00
mm/mm_init: fix incorrect node_spanned_pages Current node_spanned_pages is got as a summation of all zone's spanned page in calculate_node_totalpages(). Generally this is good, but if we use kernelcore=mirror, it is would be wrong. Without kernelcore=mirror: The test machine has below memory layout: memory[0x0] [0x0000000000001000-0x000000000009efff], 0x000000000009e000 bytes on node 0 flags: 0x0 memory[0x1] [0x0000000000100000-0x00000000bffdefff], 0x00000000bfedf000 bytes on node 0 flags: 0x0 memory[0x2] [0x0000000100000000-0x00000001bfffffff], 0x00000000c0000000 bytes on node 0 flags: 0x0 And the Zone range is: DMA [mem 0x0000000000001000-0x0000000000ffffff] DMA32 [mem 0x0000000001000000-0x00000000ffffffff] Normal [mem 0x0000000100000000-0x00000001bfffffff] Then we see, with spanned_pages printed: On node 0 spanned_pages: 1835007 totalpages: 1572733 With kernelcore=mirror: The test machine has below memory layout: memory[0x0] [0x0000000000001000-0x000000000009efff], 0x000000000009e000 bytes on node 0 flags: 0x2 memory[0x1] [0x0000000000100000-0x00000000bffdefff], 0x00000000bfedf000 bytes on node 0 flags: 0x2 memory[0x2] [0x0000000100000000-0x000000013fffffff], 0x0000000040000000 bytes on node 0 flags: 0x2 memory[0x3] [0x0000000140000000-0x00000001bfffffff], 0x0000000080000000 bytes on node 0 flags: 0x0 And the Zone range is: DMA [mem 0x0000000000001000-0x0000000000ffffff] DMA32 [mem 0x0000000001000000-0x00000000ffffffff] Normal [mem 0x0000000100000000-0x00000001bfffffff] Device empty Movable zone start for each node Node 0: 0x0000000140000000 Then we see, with spanned_pages printed: On node 0 spanned_pages: 2359295 totalpages: 1572733 The total range of memory on node 0 doesn't change, but the spanned_pages becomes much larger. The reason is when kernelcore=mirror is specified, the range of Zone Normal and Zone Movable would overlap. So the overlapped range would be calculated twice. A wrong node_spanned_pages would effect defer_init(), since each zone_end_pfn is less than pgdat_end_pfn(). As we already passed in node_start_pfn and node_end_pfn, fix this by get it from (node_start_pfn - node_end_pfn) directly. Fixes: 342332e6a925 ("mm/page_alloc.c: introduce kernelcore=mirror option") Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Cc: Yuan Liu <yuan1.liu@intel.com> Link: https://patch.msgid.link/20260622022403.16375-1-richard.weiyang@gmail.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-22 02:24:03 +00:00
mm/mm_init: fix incorrect node_spanned_pages Current node_spanned_pages is got as a summation of all zone's spanned page in calculate_node_totalpages(). Generally this is good, but if we use kernelcore=mirror, it is would be wrong. Without kernelcore=mirror: The test machine has below memory layout: memory[0x0] [0x0000000000001000-0x000000000009efff], 0x000000000009e000 bytes on node 0 flags: 0x0 memory[0x1] [0x0000000000100000-0x00000000bffdefff], 0x00000000bfedf000 bytes on node 0 flags: 0x0 memory[0x2] [0x0000000100000000-0x00000001bfffffff], 0x00000000c0000000 bytes on node 0 flags: 0x0 And the Zone range is: DMA [mem 0x0000000000001000-0x0000000000ffffff] DMA32 [mem 0x0000000001000000-0x00000000ffffffff] Normal [mem 0x0000000100000000-0x00000001bfffffff] Then we see, with spanned_pages printed: On node 0 spanned_pages: 1835007 totalpages: 1572733 With kernelcore=mirror: The test machine has below memory layout: memory[0x0] [0x0000000000001000-0x000000000009efff], 0x000000000009e000 bytes on node 0 flags: 0x2 memory[0x1] [0x0000000000100000-0x00000000bffdefff], 0x00000000bfedf000 bytes on node 0 flags: 0x2 memory[0x2] [0x0000000100000000-0x000000013fffffff], 0x0000000040000000 bytes on node 0 flags: 0x2 memory[0x3] [0x0000000140000000-0x00000001bfffffff], 0x0000000080000000 bytes on node 0 flags: 0x0 And the Zone range is: DMA [mem 0x0000000000001000-0x0000000000ffffff] DMA32 [mem 0x0000000001000000-0x00000000ffffffff] Normal [mem 0x0000000100000000-0x00000001bfffffff] Device empty Movable zone start for each node Node 0: 0x0000000140000000 Then we see, with spanned_pages printed: On node 0 spanned_pages: 2359295 totalpages: 1572733 The total range of memory on node 0 doesn't change, but the spanned_pages becomes much larger. The reason is when kernelcore=mirror is specified, the range of Zone Normal and Zone Movable would overlap. So the overlapped range would be calculated twice. A wrong node_spanned_pages would effect defer_init(), since each zone_end_pfn is less than pgdat_end_pfn(). As we already passed in node_start_pfn and node_end_pfn, fix this by get it from (node_start_pfn - node_end_pfn) directly. Fixes: 342332e6a925 ("mm/page_alloc.c: introduce kernelcore=mirror option") Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Cc: Yuan Liu <yuan1.liu@intel.com> Link: https://patch.msgid.link/20260622022403.16375-1-richard.weiyang@gmail.com Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-06-22 02:24:03 +00:00
mm: introduce for_each_free_list() Patch series "mm: misc cleanups from __GFP_UNMAPPED series". In v2 of the __GFP_UNMAPPED series [0], we realised that some of the patches could potentially be merged as independent cleanups. These are all independent of one another, if you think some are useful cleanups and others are pointless churn, it should be fine to just pick whatever subset you prefer. No functional change intended. This patch (of 4): There are a couple of places that iterate over the freelists with awareness of the data structures' layout. It seems ideally, code outside of mm should not be aware of the page allocator's freelists at all. But, this patch just doesn't hide them completely, it's just a meek incremental step in that direction: provide a macro to iterate over it without needing to be aware of the actual struct fields. Link: https://lore.kernel.org/20260513-page_alloc-unmapped-prep-v1-0-dacdf5402be8@google.com Link: https://lore.kernel.org/20260513-page_alloc-unmapped-prep-v1-1-dacdf5402be8@google.com Link: https://lore.kernel.org/all/20260320-page_alloc-unmapped-v2-0-28bf1bd54f41@google.com/ [0] Signed-off-by: Brendan Jackman <jackmanb@google.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kairui Song <kasong@tencent.com> Cc: Len Brown <lenb@kernel.org> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: "Rafael J. Wysocki" <rafael@kernel.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-05-13 12:35:13 +00:00
mm: Add support for unaccepted memory UEFI Specification version 2.9 introduces the concept of memory acceptance. Some Virtual Machine platforms, such as Intel TDX or AMD SEV-SNP, require memory to be accepted before it can be used by the guest. Accepting happens via a protocol specific to the Virtual Machine platform. There are several ways the kernel can deal with unaccepted memory: 1. Accept all the memory during boot. It is easy to implement and it doesn't have runtime cost once the system is booted. The downside is very long boot time. Accept can be parallelized to multiple CPUs to keep it manageable (i.e. via DEFERRED_STRUCT_PAGE_INIT), but it tends to saturate memory bandwidth and does not scale beyond the point. 2. Accept a block of memory on the first use. It requires more infrastructure and changes in page allocator to make it work, but it provides good boot time. On-demand memory accept means latency spikes every time kernel steps onto a new memory block. The spikes will go away once workload data set size gets stabilized or all memory gets accepted. 3. Accept all memory in background. Introduce a thread (or multiple) that gets memory accepted proactively. It will minimize time the system experience latency spikes on memory allocation while keeping low boot time. This approach cannot function on its own. It is an extension of #2: background memory acceptance requires functional scheduler, but the page allocator may need to tap into unaccepted memory before that. The downside of the approach is that these threads also steal CPU cycles and memory bandwidth from the user's workload and may hurt user experience. Implement #1 and #2 for now. #2 is the default. Some workloads may want to use #1 with accept_memory=eager in kernel command line. #3 can be implemented later based on user's demands. Support of unaccepted memory requires a few changes in core-mm code: - memblock accepts memory on allocation. It serves early boot memory allocations and doesn't limit them to pre-accepted pool of memory. - page allocator accepts memory on the first allocation of the page. When kernel runs out of accepted memory, it accepts memory until the high watermark is reached. It helps to minimize fragmentation. EFI code will provide two helpers if the platform supports unaccepted memory: - accept_memory() makes a range of physical addresses accepted. - range_contains_unaccepted_memory() checks anything within the range of physical addresses requires acceptance. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mike Rapoport <rppt@linux.ibm.com> # memblock Link: https://lore.kernel.org/r/20230606142637.5171-2-kirill.shutemov@linux.intel.com
2023-06-06 17:26:29 +03:00
mm/mm_init.c: remove meaningless calculation of zone->managed_pages in free_area_init_core() Currently, in free_area_init_core(), when initialize zone's field, a rough value is set to zone->managed_pages. That value is calculated by (zone->present_pages - memmap_pages). In the meantime, add the value to nr_all_pages and nr_kernel_pages which represent all free pages of system (only low memory or including HIGHMEM memory separately). Both of them are gonna be used in alloc_large_system_hash(). However, the rough calculation and setting of zone->managed_pages is meaningless because a) memmap pages are allocated on units of node in sparse_init() or alloc_node_mem_map(pgdat); The simple (zone->present_pages - memmap_pages) is too rough to make sense for zone; b) the set zone->managed_pages will be zeroed out and reset with acutal value in mem_init() via memblock_free_all(). Before the resetting, no buddy allocation request is issued. Here, remove the meaningless and complicated calculation of (zone->present_pages - memmap_pages), directly set zone->managed_pages as zone->present_pages for now. It will be adjusted in mem_init(). And also remove the assignment of nr_all_pages and nr_kernel_pages in free_area_init_core(). Instead, call the newly added calc_nr_kernel_pages() to count up all free but not reserved memory in memblock and assign to nr_all_pages and nr_kernel_pages. The counting excludes memmap_pages, and other kernel used data, which is more accurate than old way and simpler, and can also cover the ppc required arch_reserved_kernel_pages() case. And also clean up the outdated code comment above free_area_init_core(). And free_area_init_core() is easy to understand now, no need to add words to explain. [bhe@redhat.com: initialize zone->managed_pages as zone->present_pages for now] Link: https://lkml.kernel.org/r/ZgU0bsJ2FEjykvju@MiWiFi-R3L-srv Link: https://lkml.kernel.org/r/20240325145646.1044760-5-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-25 22:56:44 +08:00
mm/mm_init.c: remove meaningless calculation of zone->managed_pages in free_area_init_core() Currently, in free_area_init_core(), when initialize zone's field, a rough value is set to zone->managed_pages. That value is calculated by (zone->present_pages - memmap_pages). In the meantime, add the value to nr_all_pages and nr_kernel_pages which represent all free pages of system (only low memory or including HIGHMEM memory separately). Both of them are gonna be used in alloc_large_system_hash(). However, the rough calculation and setting of zone->managed_pages is meaningless because a) memmap pages are allocated on units of node in sparse_init() or alloc_node_mem_map(pgdat); The simple (zone->present_pages - memmap_pages) is too rough to make sense for zone; b) the set zone->managed_pages will be zeroed out and reset with acutal value in mem_init() via memblock_free_all(). Before the resetting, no buddy allocation request is issued. Here, remove the meaningless and complicated calculation of (zone->present_pages - memmap_pages), directly set zone->managed_pages as zone->present_pages for now. It will be adjusted in mem_init(). And also remove the assignment of nr_all_pages and nr_kernel_pages in free_area_init_core(). Instead, call the newly added calc_nr_kernel_pages() to count up all free but not reserved memory in memblock and assign to nr_all_pages and nr_kernel_pages. The counting excludes memmap_pages, and other kernel used data, which is more accurate than old way and simpler, and can also cover the ppc required arch_reserved_kernel_pages() case. And also clean up the outdated code comment above free_area_init_core(). And free_area_init_core() is easy to understand now, no need to add words to explain. [bhe@redhat.com: initialize zone->managed_pages as zone->present_pages for now] Link: https://lkml.kernel.org/r/ZgU0bsJ2FEjykvju@MiWiFi-R3L-srv Link: https://lkml.kernel.org/r/20240325145646.1044760-5-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-25 22:56:44 +08:00
mm/mm_init.c: remove meaningless calculation of zone->managed_pages in free_area_init_core() Currently, in free_area_init_core(), when initialize zone's field, a rough value is set to zone->managed_pages. That value is calculated by (zone->present_pages - memmap_pages). In the meantime, add the value to nr_all_pages and nr_kernel_pages which represent all free pages of system (only low memory or including HIGHMEM memory separately). Both of them are gonna be used in alloc_large_system_hash(). However, the rough calculation and setting of zone->managed_pages is meaningless because a) memmap pages are allocated on units of node in sparse_init() or alloc_node_mem_map(pgdat); The simple (zone->present_pages - memmap_pages) is too rough to make sense for zone; b) the set zone->managed_pages will be zeroed out and reset with acutal value in mem_init() via memblock_free_all(). Before the resetting, no buddy allocation request is issued. Here, remove the meaningless and complicated calculation of (zone->present_pages - memmap_pages), directly set zone->managed_pages as zone->present_pages for now. It will be adjusted in mem_init(). And also remove the assignment of nr_all_pages and nr_kernel_pages in free_area_init_core(). Instead, call the newly added calc_nr_kernel_pages() to count up all free but not reserved memory in memblock and assign to nr_all_pages and nr_kernel_pages. The counting excludes memmap_pages, and other kernel used data, which is more accurate than old way and simpler, and can also cover the ppc required arch_reserved_kernel_pages() case. And also clean up the outdated code comment above free_area_init_core(). And free_area_init_core() is easy to understand now, no need to add words to explain. [bhe@redhat.com: initialize zone->managed_pages as zone->present_pages for now] Link: https://lkml.kernel.org/r/ZgU0bsJ2FEjykvju@MiWiFi-R3L-srv Link: https://lkml.kernel.org/r/20240325145646.1044760-5-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-25 22:56:44 +08:00
arch, mm: set max_mapnr when allocating memory map for FLATMEM max_mapnr is essentially the size of the memory map for systems that use FLATMEM. There is no reason to calculate it in each and every architecture when it's anyway calculated in alloc_node_mem_map(). Drop setting of max_mapnr from architecture code and set it once in alloc_node_mem_map(). While on it, move definition of mem_map and max_mapnr to mm/mm_init.c so there won't be two copies for MMU and !MMU variants. Link: https://lkml.kernel.org/r/20250313135003.836600-10-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86] Tested-by: Mark Brown <broonie@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Guo Ren (csky) <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russel King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-13 15:49:59 +02:00
mm: don't account memmap per-node Fix invalid access to pgdat during hot-remove operation: ndctl users reported a GPF when trying to destroy a namespace: $ ndctl destroy-namespace all -r all -f Segmentation fault dmesg: Oops: general protection fault, probably for non-canonical address 0xdffffc0000005650: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: probably user-memory-access in range [0x000000000002b280-0x000000000002b287] CPU: 26 UID: 0 PID: 1868 Comm: ndctl Not tainted 6.11.0-rc1 #1 Hardware name: Dell Inc. PowerEdge R640/08HT8T, BIOS 2.20.1 09/13/2023 RIP: 0010:mod_node_page_state+0x2a/0x110 cxl-test users report a GPF when trying to unload the test module: $ modrpobe -r cxl-test dmesg BUG: unable to handle page fault for address: 0000000000004200 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] PREEMPT SMP PTI CPU: 0 UID: 0 PID: 1076 Comm: modprobe Tainted: G O N 6.11.0-rc1 #197 Tainted: [O]=OOT_MODULE, [N]=TEST Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/15 RIP: 0010:mod_node_page_state+0x6/0x90 Currently, when memory is hot-plugged or hot-removed the accounting is done based on the assumption that memmap is allocated from the same node as the hot-plugged/hot-removed memory, which is not always the case. In addition, there are challenges with keeping the node id of the memory that is being remove to the time when memmap accounting is actually performed: since this is done after remove_pfn_range_from_zone(), and also after remove_memory_block_devices(). Meaning that we cannot use pgdat nor walking though memblocks to get the nid. Given all of that, account the memmap overhead system wide instead. For this we are going to be using global atomic counters, but given that memmap size is rarely modified, and normally is only modified either during early boot when there is only one CPU, or under a hotplug global mutex lock, therefore there is no need for per-cpu optimizations. Also, while we are here rename nr_memmap to nr_memmap_pages, and nr_memmap_boot to nr_memmap_boot_pages to be self explanatory that the units are in page count. [pasha.tatashin@soleen.com: address a few nits from David Hildenbrand] Link: https://lkml.kernel.org/r/20240809191020.1142142-4-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20240809191020.1142142-4-pasha.tatashin@soleen.com Link: https://lkml.kernel.org/r/20240808213437.682006-4-pasha.tatashin@soleen.com Fixes: 15995a352474 ("mm: report per-page metadata information") Signed-off-by: Pasha Tatashin <pasha.tatashin@soleen.com> Reported-by: Yi Zhang <yi.zhang@redhat.com> Closes: https://lore.kernel.org/linux-cxl/CAHj4cs9Ax1=CoJkgBGP_+sNu6-6=6v=_L-ZBZY0bVLD3wUWZQg@mail.gmail.com Reported-by: Alison Schofield <alison.schofield@intel.com> Closes: https://lore.kernel.org/linux-mm/Zq0tPd2h6alFz8XF@aschofie-mobl2/#t Tested-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Alison Schofield <alison.schofield@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Tested-by: Yi Zhang <yi.zhang@redhat.com> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Fan Ni <fan.ni@samsung.com> Cc: Joel Granados <j.granados@samsung.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Li Zhijian <lizhijian@fujitsu.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Sourav Panda <souravpanda@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yosry Ahmed <yosryahmed@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-08 21:34:36 +00:00
arch, mm: set max_mapnr when allocating memory map for FLATMEM max_mapnr is essentially the size of the memory map for systems that use FLATMEM. There is no reason to calculate it in each and every architecture when it's anyway calculated in alloc_node_mem_map(). Drop setting of max_mapnr from architecture code and set it once in alloc_node_mem_map(). While on it, move definition of mem_map and max_mapnr to mm/mm_init.c so there won't be two copies for MMU and !MMU variants. Link: https://lkml.kernel.org/r/20250313135003.836600-10-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86] Tested-by: Mark Brown <broonie@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Guo Ren (csky) <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russel King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-13 15:49:59 +02:00
arch, mm: set max_mapnr when allocating memory map for FLATMEM max_mapnr is essentially the size of the memory map for systems that use FLATMEM. There is no reason to calculate it in each and every architecture when it's anyway calculated in alloc_node_mem_map(). Drop setting of max_mapnr from architecture code and set it once in alloc_node_mem_map(). While on it, move definition of mem_map and max_mapnr to mm/mm_init.c so there won't be two copies for MMU and !MMU variants. Link: https://lkml.kernel.org/r/20250313135003.836600-10-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86] Tested-by: Mark Brown <broonie@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Guo Ren (csky) <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russel King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-13 15:49:59 +02:00
arch, mm: set high_memory in free_area_init() high_memory defines upper bound on the directly mapped memory. This bound is defined by the beginning of ZONE_HIGHMEM when a system has high memory and by the end of memory otherwise. All this is known to generic memory management initialization code that can set high_memory while initializing core mm structures. Add a generic calculation of high_memory to free_area_init() and remove per-architecture calculation except for the architectures that set and use high_memory earlier than that. Link: https://lkml.kernel.org/r/20250313135003.836600-11-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86] Tested-by: Mark Brown <broonie@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Guo Ren (csky) <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russel King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-13 15:50:00 +02:00
arch, mm: consolidate initialization of nodes, zones and memory map To initialize node, zone and memory map data structures every architecture calls free_area_init() during setup_arch() and passes it an array of zone limits. Beside code duplication it creates "interesting" ordering cases between allocation and initialization of hugetlb and the memory map. Some architectures allocate hugetlb pages very early in setup_arch() in certain cases, some only create hugetlb CMA areas in setup_arch() and sometimes hugetlb allocations happen mm_core_init(). With arch_zone_limits_init() helper available now on all architectures it is no longer necessary to call free_area_init() from architecture setup code. Rather core MM initialization can call arch_zone_limits_init() in a single place. This allows to unify ordering of hugetlb vs memory map allocation and initialization. Remove the call to free_area_init() from architecture specific code and place it in a new mm_core_init_early() function that is called immediately after setup_arch(). After this refactoring it is possible to consolidate hugetlb allocations and eliminate differences in ordering of hugetlb and memory map initialization among different architectures. As the first step of this consolidation move hugetlb_bootmem_alloc() to mm_core_early_init(). Link: https://lkml.kernel.org/r/20260111082105.290734-24-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alex Shi <alexs@kernel.org> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Klara Modin <klarasmodin@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-11 10:20:57 +02:00
arch, mm: consolidate initialization of nodes, zones and memory map To initialize node, zone and memory map data structures every architecture calls free_area_init() during setup_arch() and passes it an array of zone limits. Beside code duplication it creates "interesting" ordering cases between allocation and initialization of hugetlb and the memory map. Some architectures allocate hugetlb pages very early in setup_arch() in certain cases, some only create hugetlb CMA areas in setup_arch() and sometimes hugetlb allocations happen mm_core_init(). With arch_zone_limits_init() helper available now on all architectures it is no longer necessary to call free_area_init() from architecture setup code. Rather core MM initialization can call arch_zone_limits_init() in a single place. This allows to unify ordering of hugetlb vs memory map allocation and initialization. Remove the call to free_area_init() from architecture specific code and place it in a new mm_core_init_early() function that is called immediately after setup_arch(). After this refactoring it is possible to consolidate hugetlb allocations and eliminate differences in ordering of hugetlb and memory map initialization among different architectures. As the first step of this consolidation move hugetlb_bootmem_alloc() to mm_core_early_init(). Link: https://lkml.kernel.org/r/20260111082105.290734-24-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alex Shi <alexs@kernel.org> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Klara Modin <klarasmodin@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-11 10:20:57 +02:00
arch, mm: consolidate initialization of nodes, zones and memory map To initialize node, zone and memory map data structures every architecture calls free_area_init() during setup_arch() and passes it an array of zone limits. Beside code duplication it creates "interesting" ordering cases between allocation and initialization of hugetlb and the memory map. Some architectures allocate hugetlb pages very early in setup_arch() in certain cases, some only create hugetlb CMA areas in setup_arch() and sometimes hugetlb allocations happen mm_core_init(). With arch_zone_limits_init() helper available now on all architectures it is no longer necessary to call free_area_init() from architecture setup code. Rather core MM initialization can call arch_zone_limits_init() in a single place. This allows to unify ordering of hugetlb vs memory map allocation and initialization. Remove the call to free_area_init() from architecture specific code and place it in a new mm_core_init_early() function that is called immediately after setup_arch(). After this refactoring it is possible to consolidate hugetlb allocations and eliminate differences in ordering of hugetlb and memory map initialization among different architectures. As the first step of this consolidation move hugetlb_bootmem_alloc() to mm_core_early_init(). Link: https://lkml.kernel.org/r/20260111082105.290734-24-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alex Shi <alexs@kernel.org> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Klara Modin <klarasmodin@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-11 10:20:57 +02:00
mm: fix NULL NODE_DATA dereference for memoryless nodes on boot Commit d49004c5f0c1 ("arch, mm: consolidate initialization of nodes, zones and memory map") moved free_area_init() from setup_arch() to mm_core_init_early(), which runs after setup_arch() returns. This changed the ordering relative to init_cpu_to_node() on x86. Before the commit, free_area_init() ran during paging_init() (called from setup_arch()) *before* init_cpu_to_node(). After the commit, it runs *after* init_cpu_to_node(). On machines with memoryless NUMA nodes (e.g., node 0 has CPUs but no memory), this causes a NULL pointer dereference: 1. numa_register_nodes() skips memoryless nodes: no alloc_node_data() and no node_set_online() for them. 2. init_cpu_to_node() sets memoryless nodes online (they have CPUs) but does not allocate NODE_DATA. 3. free_area_init() checks "if (!node_online(nid))" to decide whether to call alloc_offline_node_data(). Since the memoryless node is now online, the allocation is skipped, leaving NODE_DATA(nid) == NULL. 4. The immediate "pgdat = NODE_DATA(nid)" dereferences NULL. The crash happens before console_init(), so no output is visible without earlyprintk. With earlyprintk enabled, the following panic is observed: BUG: unable to handle page fault for address: 000000000002a1e0 Oops: Oops: 0000 [#1] SMP NOPTI RIP: 0010:free_area_init_node+0x3a/0x540 Call Trace: <TASK> free_area_init+0x331/0x4e0 start_kernel+0x69/0x4a0 x86_64_start_reservations+0x24/0x30 x86_64_start_kernel+0x125/0x130 common_startup_64+0x13e/0x148 </TASK> Kernel panic - not syncing: Attempted to kill the idle task! Fix this by checking "if (!NODE_DATA(nid))" instead of "if (!node_online(nid))". This directly tests whether the per-node data structure needs to be allocated, regardless of the node's online status. This change is also safe for non-x86 architectures as they all allocate NODE_DATA for every node including memoryless ones, so the check simply evaluates to false with no change in behavior. Link: https://lkml.kernel.org/r/20260222115702.3659-1-ming.lei@redhat.com Fixes: d49004c5f0c1 ("arch, mm: consolidate initialization of nodes, zones and memory map") Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-22 19:57:02 +08:00
mm: drop CONFIG_HAVE_ARCH_NODEDATA_EXTENSION There are no users of HAVE_ARCH_NODEDATA_EXTENSION left, so arch_alloc_nodedata() and arch_refresh_nodedata() are not needed anymore. Replace the call to arch_alloc_nodedata() in free_area_init() with a new helper alloc_offline_node_data(), remove arch_refresh_nodedata() and cleanup include/linux/memory_hotplug.h from the associated ifdefery. Link: https://lkml.kernel.org/r/20240807064110.1003856-9-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Tested-by: Zi Yan <ziy@nvidia.com> # for x86_64 and arm64 Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: David S. Miller <davem@davemloft.net> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Rob Herring (Arm) <robh@kernel.org> Cc: Samuel Holland <samuel.holland@sifive.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-08-07 09:40:52 +03:00
drivers/base/node: fold register_node() into register_one_node() Patch series "drivers/base/node: fold node register and unregister functions", v2. The first patch merges register_one_node() and register_node(), leaving a single register_node() function. The second patch merges unregister_one_node() and unregister_node(), leaving a single unregister_node() function. There are no functional changes in these patches. This patch (of 2): register_node() is only called from register_one_node(). This patch folds register_node() into its only caller and renames register_one_node() to register_node(). This reduces unnecessary indirection and simplifies the code structure. No functional changes are introduced. [akpm@linux-foundation.org: fix kerneldoc, per David] Link: https://lkml.kernel.org/r/cover.1760097207.git.donettom@linux.ibm.com Link: https://lkml.kernel.org/r/910853c9dd61f7a2190a56cba101e73e9c6859be.1760097207.git.donettom@linux.ibm.com Signed-off-by: Donet Tom <donettom@linux.ibm.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: SeongJae Park <sj@kernel.org> Acked-by: David Hildenbrand <david@redhat.com> Cc: Aboorva Devarajan <aboorvad@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-14 21:09:16 +05:30
mm/mm_init.c: remove meaningless calculation of zone->managed_pages in free_area_init_core() Currently, in free_area_init_core(), when initialize zone's field, a rough value is set to zone->managed_pages. That value is calculated by (zone->present_pages - memmap_pages). In the meantime, add the value to nr_all_pages and nr_kernel_pages which represent all free pages of system (only low memory or including HIGHMEM memory separately). Both of them are gonna be used in alloc_large_system_hash(). However, the rough calculation and setting of zone->managed_pages is meaningless because a) memmap pages are allocated on units of node in sparse_init() or alloc_node_mem_map(pgdat); The simple (zone->present_pages - memmap_pages) is too rough to make sense for zone; b) the set zone->managed_pages will be zeroed out and reset with acutal value in mem_init() via memblock_free_all(). Before the resetting, no buddy allocation request is issued. Here, remove the meaningless and complicated calculation of (zone->present_pages - memmap_pages), directly set zone->managed_pages as zone->present_pages for now. It will be adjusted in mem_init(). And also remove the assignment of nr_all_pages and nr_kernel_pages in free_area_init_core(). Instead, call the newly added calc_nr_kernel_pages() to count up all free but not reserved memory in memblock and assign to nr_all_pages and nr_kernel_pages. The counting excludes memmap_pages, and other kernel used data, which is more accurate than old way and simpler, and can also cover the ppc required arch_reserved_kernel_pages() case. And also clean up the outdated code comment above free_area_init_core(). And free_area_init_core() is easy to understand now, no need to add words to explain. [bhe@redhat.com: initialize zone->managed_pages as zone->present_pages for now] Link: https://lkml.kernel.org/r/ZgU0bsJ2FEjykvju@MiWiFi-R3L-srv Link: https://lkml.kernel.org/r/20240325145646.1044760-5-bhe@redhat.com Signed-off-by: Baoquan He <bhe@redhat.com> Reviewed-by: Mike Rapoport (IBM) <rppt@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-03-25 22:56:44 +08:00
arch, mm: set high_memory in free_area_init() high_memory defines upper bound on the directly mapped memory. This bound is defined by the beginning of ZONE_HIGHMEM when a system has high memory and by the end of memory otherwise. All this is known to generic memory management initialization code that can set high_memory while initializing core mm structures. Add a generic calculation of high_memory to free_area_init() and remove per-architecture calculation except for the architectures that set and use high_memory earlier than that. Link: https://lkml.kernel.org/r/20250313135003.836600-11-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86] Tested-by: Mark Brown <broonie@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Guo Ren (csky) <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russel King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-13 15:50:00 +02:00
mm: pass meminit_context to __free_pages_core() Patch series "mm/memory_hotplug: use PageOffline() instead of PageReserved() for !ZONE_DEVICE". This can be a considered a long-overdue follow-up to some parts of [1]. The patches are based on [2], but they are not strictly required -- just makes it clearer why we can use adjust_managed_page_count() for memory hotplug without going into details about highmem. We stop initializing pages with PageReserved() in memory hotplug code -- except when dealing with ZONE_DEVICE for now. Instead, we use PageOffline(): all pages are initialized to PageOffline() when onlining a memory section, and only the ones actually getting exposed to the system/page allocator will get PageOffline cleared. This way, we enlighten memory hotplug more about PageOffline() pages and can cleanup some hacks we have in virtio-mem code. What about ZONE_DEVICE? PageOffline() is wrong, but we might just stop using PageReserved() for them later by simply checking for is_zone_device_page() at suitable places. That will be a separate patch set / proposal. This primarily affects virtio-mem, HV-balloon and XEN balloon. I only briefly tested with virtio-mem, which benefits most from these cleanups. [1] https://lore.kernel.org/all/20191024120938.11237-1-david@redhat.com/ [2] https://lkml.kernel.org/r/20240607083711.62833-1-david@redhat.com This patch (of 3): In preparation for further changes, let's teach __free_pages_core() about the differences of memory hotplug handling. Move the memory hotplug specific handling from generic_online_page() to __free_pages_core(), use adjust_managed_page_count() on the memory hotplug path, and spell out why memory freed via memblock cannot currently use adjust_managed_page_count(). [david@redhat.com: add missed CONFIG_DEFERRED_STRUCT_PAGE_INIT] Link: https://lkml.kernel.org/r/b72e6efd-fb0a-459c-b1a0-88a98e5b19e2@redhat.com [david@redhat.com: fix up the memblock comment, per Oscar] Link: https://lkml.kernel.org/r/2ed64218-7f3b-4302-a5dc-27f060654fe2@redhat.com [david@redhat.com: add the parameter name also in the declaration] Link: https://lkml.kernel.org/r/ca575956-f0dd-4fb9-a307-6b7621681ed9@redhat.com Link: https://lkml.kernel.org/r/20240607090939.89524-1-david@redhat.com Link: https://lkml.kernel.org/r/20240607090939.89524-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eugenio Pérez <eperezma@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Marco Elver <elver@google.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Wei Liu <wei.liu@kernel.org> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-07 11:09:36 +02:00
mm: Add support for unaccepted memory UEFI Specification version 2.9 introduces the concept of memory acceptance. Some Virtual Machine platforms, such as Intel TDX or AMD SEV-SNP, require memory to be accepted before it can be used by the guest. Accepting happens via a protocol specific to the Virtual Machine platform. There are several ways the kernel can deal with unaccepted memory: 1. Accept all the memory during boot. It is easy to implement and it doesn't have runtime cost once the system is booted. The downside is very long boot time. Accept can be parallelized to multiple CPUs to keep it manageable (i.e. via DEFERRED_STRUCT_PAGE_INIT), but it tends to saturate memory bandwidth and does not scale beyond the point. 2. Accept a block of memory on the first use. It requires more infrastructure and changes in page allocator to make it work, but it provides good boot time. On-demand memory accept means latency spikes every time kernel steps onto a new memory block. The spikes will go away once workload data set size gets stabilized or all memory gets accepted. 3. Accept all memory in background. Introduce a thread (or multiple) that gets memory accepted proactively. It will minimize time the system experience latency spikes on memory allocation while keeping low boot time. This approach cannot function on its own. It is an extension of #2: background memory acceptance requires functional scheduler, but the page allocator may need to tap into unaccepted memory before that. The downside of the approach is that these threads also steal CPU cycles and memory bandwidth from the user's workload and may hurt user experience. Implement #1 and #2 for now. #2 is the default. Some workloads may want to use #1 with accept_memory=eager in kernel command line. #3 can be implemented later based on user's demands. Support of unaccepted memory requires a few changes in core-mm code: - memblock accepts memory on allocation. It serves early boot memory allocations and doesn't limit them to pre-accepted pool of memory. - page allocator accepts memory on the first allocation of the page. When kernel runs out of accepted memory, it accepts memory until the high watermark is reached. It helps to minimize fragmentation. EFI code will provide two helpers if the platform supports unaccepted memory: - accept_memory() makes a range of physical addresses accepted. - range_contains_unaccepted_memory() checks anything within the range of physical addresses requires acceptance. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mike Rapoport <rppt@linux.ibm.com> # memblock Link: https://lore.kernel.org/r/20230606142637.5171-2-kirill.shutemov@linux.intel.com
2023-06-06 17:26:29 +03:00
mm/mm_init: don't cond_resched() in deferred_init_memmap_chunk() if called from deferred_grow_zone() Commit 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") made deferred_grow_zone() call deferred_init_memmap_chunk() within a pgdat_resize_lock() critical section with irqs disabled. It did check for irqs_disabled() in deferred_init_memmap_chunk() to avoid calling cond_resched(). For a PREEMPT_RT kernel build, however, spin_lock_irqsave() does not disable interrupt but rcu_read_lock() is called. This leads to the following bug report. BUG: sleeping function called from invalid context at mm/mm_init.c:2091 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 0, expected: 0 RCU nest depth: 1, expected: 0 3 locks held by swapper/0/1: #0: ffff80008471b7a0 (sched_domains_mutex){+.+.}-{4:4}, at: sched_domains_mutex_lock+0x28/0x40 #1: ffff003bdfffef48 (&pgdat->node_size_lock){+.+.}-{3:3}, at: deferred_grow_zone+0x140/0x278 #2: ffff800084acf600 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1b4/0x408 CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.19.0-rc6-test #1 PREEMPT_{RT,(full) } Tainted: [W]=WARN Call trace: show_stack+0x20/0x38 (C) dump_stack_lvl+0xdc/0xf8 dump_stack+0x1c/0x28 __might_resched+0x384/0x530 deferred_init_memmap_chunk+0x560/0x688 deferred_grow_zone+0x190/0x278 _deferred_grow_zone+0x18/0x30 get_page_from_freelist+0x780/0xf78 __alloc_frozen_pages_noprof+0x1dc/0x348 alloc_slab_page+0x30/0x110 allocate_slab+0x98/0x2a0 new_slab+0x4c/0x80 ___slab_alloc+0x5a4/0x770 __slab_alloc.constprop.0+0x88/0x1e0 __kmalloc_node_noprof+0x2c0/0x598 __sdt_alloc+0x3b8/0x728 build_sched_domains+0xe0/0x1260 sched_init_domains+0x14c/0x1c8 sched_init_smp+0x9c/0x1d0 kernel_init_freeable+0x218/0x358 kernel_init+0x28/0x208 ret_from_fork+0x10/0x20 Fix it adding a new argument to deferred_init_memmap_chunk() to explicitly tell it if cond_resched() is allowed or not instead of relying on some current state information which may vary depending on the exact kernel configuration options that are enabled. Link: https://lkml.kernel.org/r/20260122184343.546627-1-longman@redhat.com Fixes: 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") Signed-off-by: Waiman Long <longman@redhat.com> Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: <stable@vger.kernrl.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-22 13:43:43 -05:00
mm/mm_init: don't cond_resched() in deferred_init_memmap_chunk() if called from deferred_grow_zone() Commit 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") made deferred_grow_zone() call deferred_init_memmap_chunk() within a pgdat_resize_lock() critical section with irqs disabled. It did check for irqs_disabled() in deferred_init_memmap_chunk() to avoid calling cond_resched(). For a PREEMPT_RT kernel build, however, spin_lock_irqsave() does not disable interrupt but rcu_read_lock() is called. This leads to the following bug report. BUG: sleeping function called from invalid context at mm/mm_init.c:2091 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 0, expected: 0 RCU nest depth: 1, expected: 0 3 locks held by swapper/0/1: #0: ffff80008471b7a0 (sched_domains_mutex){+.+.}-{4:4}, at: sched_domains_mutex_lock+0x28/0x40 #1: ffff003bdfffef48 (&pgdat->node_size_lock){+.+.}-{3:3}, at: deferred_grow_zone+0x140/0x278 #2: ffff800084acf600 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1b4/0x408 CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.19.0-rc6-test #1 PREEMPT_{RT,(full) } Tainted: [W]=WARN Call trace: show_stack+0x20/0x38 (C) dump_stack_lvl+0xdc/0xf8 dump_stack+0x1c/0x28 __might_resched+0x384/0x530 deferred_init_memmap_chunk+0x560/0x688 deferred_grow_zone+0x190/0x278 _deferred_grow_zone+0x18/0x30 get_page_from_freelist+0x780/0xf78 __alloc_frozen_pages_noprof+0x1dc/0x348 alloc_slab_page+0x30/0x110 allocate_slab+0x98/0x2a0 new_slab+0x4c/0x80 ___slab_alloc+0x5a4/0x770 __slab_alloc.constprop.0+0x88/0x1e0 __kmalloc_node_noprof+0x2c0/0x598 __sdt_alloc+0x3b8/0x728 build_sched_domains+0xe0/0x1260 sched_init_domains+0x14c/0x1c8 sched_init_smp+0x9c/0x1d0 kernel_init_freeable+0x218/0x358 kernel_init+0x28/0x208 ret_from_fork+0x10/0x20 Fix it adding a new argument to deferred_init_memmap_chunk() to explicitly tell it if cond_resched() is allowed or not instead of relying on some current state information which may vary depending on the exact kernel configuration options that are enabled. Link: https://lkml.kernel.org/r/20260122184343.546627-1-longman@redhat.com Fixes: 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") Signed-off-by: Waiman Long <longman@redhat.com> Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: <stable@vger.kernrl.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-22 13:43:43 -05:00
mm/mm_init: don't cond_resched() in deferred_init_memmap_chunk() if called from deferred_grow_zone() Commit 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") made deferred_grow_zone() call deferred_init_memmap_chunk() within a pgdat_resize_lock() critical section with irqs disabled. It did check for irqs_disabled() in deferred_init_memmap_chunk() to avoid calling cond_resched(). For a PREEMPT_RT kernel build, however, spin_lock_irqsave() does not disable interrupt but rcu_read_lock() is called. This leads to the following bug report. BUG: sleeping function called from invalid context at mm/mm_init.c:2091 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 0, expected: 0 RCU nest depth: 1, expected: 0 3 locks held by swapper/0/1: #0: ffff80008471b7a0 (sched_domains_mutex){+.+.}-{4:4}, at: sched_domains_mutex_lock+0x28/0x40 #1: ffff003bdfffef48 (&pgdat->node_size_lock){+.+.}-{3:3}, at: deferred_grow_zone+0x140/0x278 #2: ffff800084acf600 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1b4/0x408 CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.19.0-rc6-test #1 PREEMPT_{RT,(full) } Tainted: [W]=WARN Call trace: show_stack+0x20/0x38 (C) dump_stack_lvl+0xdc/0xf8 dump_stack+0x1c/0x28 __might_resched+0x384/0x530 deferred_init_memmap_chunk+0x560/0x688 deferred_grow_zone+0x190/0x278 _deferred_grow_zone+0x18/0x30 get_page_from_freelist+0x780/0xf78 __alloc_frozen_pages_noprof+0x1dc/0x348 alloc_slab_page+0x30/0x110 allocate_slab+0x98/0x2a0 new_slab+0x4c/0x80 ___slab_alloc+0x5a4/0x770 __slab_alloc.constprop.0+0x88/0x1e0 __kmalloc_node_noprof+0x2c0/0x598 __sdt_alloc+0x3b8/0x728 build_sched_domains+0xe0/0x1260 sched_init_domains+0x14c/0x1c8 sched_init_smp+0x9c/0x1d0 kernel_init_freeable+0x218/0x358 kernel_init+0x28/0x208 ret_from_fork+0x10/0x20 Fix it adding a new argument to deferred_init_memmap_chunk() to explicitly tell it if cond_resched() is allowed or not instead of relying on some current state information which may vary depending on the exact kernel configuration options that are enabled. Link: https://lkml.kernel.org/r/20260122184343.546627-1-longman@redhat.com Fixes: 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") Signed-off-by: Waiman Long <longman@redhat.com> Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: <stable@vger.kernrl.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-22 13:43:43 -05:00
mm/mm_init: don't cond_resched() in deferred_init_memmap_chunk() if called from deferred_grow_zone() Commit 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") made deferred_grow_zone() call deferred_init_memmap_chunk() within a pgdat_resize_lock() critical section with irqs disabled. It did check for irqs_disabled() in deferred_init_memmap_chunk() to avoid calling cond_resched(). For a PREEMPT_RT kernel build, however, spin_lock_irqsave() does not disable interrupt but rcu_read_lock() is called. This leads to the following bug report. BUG: sleeping function called from invalid context at mm/mm_init.c:2091 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 0, expected: 0 RCU nest depth: 1, expected: 0 3 locks held by swapper/0/1: #0: ffff80008471b7a0 (sched_domains_mutex){+.+.}-{4:4}, at: sched_domains_mutex_lock+0x28/0x40 #1: ffff003bdfffef48 (&pgdat->node_size_lock){+.+.}-{3:3}, at: deferred_grow_zone+0x140/0x278 #2: ffff800084acf600 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1b4/0x408 CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.19.0-rc6-test #1 PREEMPT_{RT,(full) } Tainted: [W]=WARN Call trace: show_stack+0x20/0x38 (C) dump_stack_lvl+0xdc/0xf8 dump_stack+0x1c/0x28 __might_resched+0x384/0x530 deferred_init_memmap_chunk+0x560/0x688 deferred_grow_zone+0x190/0x278 _deferred_grow_zone+0x18/0x30 get_page_from_freelist+0x780/0xf78 __alloc_frozen_pages_noprof+0x1dc/0x348 alloc_slab_page+0x30/0x110 allocate_slab+0x98/0x2a0 new_slab+0x4c/0x80 ___slab_alloc+0x5a4/0x770 __slab_alloc.constprop.0+0x88/0x1e0 __kmalloc_node_noprof+0x2c0/0x598 __sdt_alloc+0x3b8/0x728 build_sched_domains+0xe0/0x1260 sched_init_domains+0x14c/0x1c8 sched_init_smp+0x9c/0x1d0 kernel_init_freeable+0x218/0x358 kernel_init+0x28/0x208 ret_from_fork+0x10/0x20 Fix it adding a new argument to deferred_init_memmap_chunk() to explicitly tell it if cond_resched() is allowed or not instead of relying on some current state information which may vary depending on the exact kernel configuration options that are enabled. Link: https://lkml.kernel.org/r/20260122184343.546627-1-longman@redhat.com Fixes: 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") Signed-off-by: Waiman Long <longman@redhat.com> Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: <stable@vger.kernrl.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-22 13:43:43 -05:00
mm/mm_init: use node's number of cpus in deferred_page_init_max_threads x86_64 is already using the node's cpu as maximum threads. Make that the default for all archs setting DEFERRED_STRUCT_PAGE_INIT. This returns to the behavior prior making the function arch-specific with commit ecd096506922 ("mm: make deferred init's max threads arch-specific"). Setting DEFERRED_STRUCT_PAGE_INIT and testing on a few arm64 platforms shows faster deferred_init_memmap completions: | | x13s | SA8775p-ride | Ampere R137-P31 | Ampere HR330 | | | Metal, 32GB | VM, 36GB | VM, 58GB | Metal, 128GB | | | 8cpus | 8cpus | 8cpus | 32cpus | |---------|-------------|--------------|-----------------|--------------| | threads | ms (%) | ms (%) | ms (%) | ms (%) | |---------|-------------|--------------|-----------------|--------------| | 1 | 108 (0%) | 72 (0%) | 224 (0%) | 324 (0%) | | cpus | 24 (-77%) | 36 (-50%) | 40 (-82%) | 56 (-82%) | Michael Ellerman reported: : On a machine here (1TB, 40 cores, 4KB pages) the existing code gives: : : [ 0.500124] node 2 deferred pages initialised in 210ms : [ 0.515790] node 3 deferred pages initialised in 230ms : [ 0.516061] node 0 deferred pages initialised in 230ms : [ 0.516522] node 7 deferred pages initialised in 230ms : [ 0.516672] node 4 deferred pages initialised in 230ms : [ 0.516798] node 6 deferred pages initialised in 230ms : [ 0.517051] node 5 deferred pages initialised in 230ms : [ 0.523887] node 1 deferred pages initialised in 240ms : : vs with the patch: : : [ 0.379613] node 0 deferred pages initialised in 90ms : [ 0.380388] node 1 deferred pages initialised in 90ms : [ 0.380540] node 4 deferred pages initialised in 100ms : [ 0.390239] node 6 deferred pages initialised in 100ms : [ 0.390249] node 2 deferred pages initialised in 100ms : [ 0.390786] node 3 deferred pages initialised in 110ms : [ 0.396721] node 5 deferred pages initialised in 110ms : [ 0.397095] node 7 deferred pages initialised in 110ms : : Which is a nice speedup. [echanude@redhat.com: v3] Link: https://lkml.kernel.org/r/20240528185455.643227-4-echanude@redhat.com Link: https://lkml.kernel.org/r/20240522203758.626932-4-echanude@redhat.com Signed-off-by: Eric Chanudet <echanude@redhat.com> Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Reviewed-by: Baoquan He <bhe@redhat.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-22 16:38:01 -04:00
mm/mm_init: use node's number of cpus in deferred_page_init_max_threads x86_64 is already using the node's cpu as maximum threads. Make that the default for all archs setting DEFERRED_STRUCT_PAGE_INIT. This returns to the behavior prior making the function arch-specific with commit ecd096506922 ("mm: make deferred init's max threads arch-specific"). Setting DEFERRED_STRUCT_PAGE_INIT and testing on a few arm64 platforms shows faster deferred_init_memmap completions: | | x13s | SA8775p-ride | Ampere R137-P31 | Ampere HR330 | | | Metal, 32GB | VM, 36GB | VM, 58GB | Metal, 128GB | | | 8cpus | 8cpus | 8cpus | 32cpus | |---------|-------------|--------------|-----------------|--------------| | threads | ms (%) | ms (%) | ms (%) | ms (%) | |---------|-------------|--------------|-----------------|--------------| | 1 | 108 (0%) | 72 (0%) | 224 (0%) | 324 (0%) | | cpus | 24 (-77%) | 36 (-50%) | 40 (-82%) | 56 (-82%) | Michael Ellerman reported: : On a machine here (1TB, 40 cores, 4KB pages) the existing code gives: : : [ 0.500124] node 2 deferred pages initialised in 210ms : [ 0.515790] node 3 deferred pages initialised in 230ms : [ 0.516061] node 0 deferred pages initialised in 230ms : [ 0.516522] node 7 deferred pages initialised in 230ms : [ 0.516672] node 4 deferred pages initialised in 230ms : [ 0.516798] node 6 deferred pages initialised in 230ms : [ 0.517051] node 5 deferred pages initialised in 230ms : [ 0.523887] node 1 deferred pages initialised in 240ms : : vs with the patch: : : [ 0.379613] node 0 deferred pages initialised in 90ms : [ 0.380388] node 1 deferred pages initialised in 90ms : [ 0.380540] node 4 deferred pages initialised in 100ms : [ 0.390239] node 6 deferred pages initialised in 100ms : [ 0.390249] node 2 deferred pages initialised in 100ms : [ 0.390786] node 3 deferred pages initialised in 110ms : [ 0.396721] node 5 deferred pages initialised in 110ms : [ 0.397095] node 7 deferred pages initialised in 110ms : : Which is a nice speedup. [echanude@redhat.com: v3] Link: https://lkml.kernel.org/r/20240528185455.643227-4-echanude@redhat.com Link: https://lkml.kernel.org/r/20240522203758.626932-4-echanude@redhat.com Signed-off-by: Eric Chanudet <echanude@redhat.com> Tested-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Reviewed-by: Baoquan He <bhe@redhat.com> Acked-by: Alexander Gordeev <agordeev@linux.ibm.com> Acked-by: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-05-22 16:38:01 -04:00
mm/mm_init: don't cond_resched() in deferred_init_memmap_chunk() if called from deferred_grow_zone() Commit 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") made deferred_grow_zone() call deferred_init_memmap_chunk() within a pgdat_resize_lock() critical section with irqs disabled. It did check for irqs_disabled() in deferred_init_memmap_chunk() to avoid calling cond_resched(). For a PREEMPT_RT kernel build, however, spin_lock_irqsave() does not disable interrupt but rcu_read_lock() is called. This leads to the following bug report. BUG: sleeping function called from invalid context at mm/mm_init.c:2091 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0 preempt_count: 0, expected: 0 RCU nest depth: 1, expected: 0 3 locks held by swapper/0/1: #0: ffff80008471b7a0 (sched_domains_mutex){+.+.}-{4:4}, at: sched_domains_mutex_lock+0x28/0x40 #1: ffff003bdfffef48 (&pgdat->node_size_lock){+.+.}-{3:3}, at: deferred_grow_zone+0x140/0x278 #2: ffff800084acf600 (rcu_read_lock){....}-{1:3}, at: rt_spin_lock+0x1b4/0x408 CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Tainted: G W 6.19.0-rc6-test #1 PREEMPT_{RT,(full) } Tainted: [W]=WARN Call trace: show_stack+0x20/0x38 (C) dump_stack_lvl+0xdc/0xf8 dump_stack+0x1c/0x28 __might_resched+0x384/0x530 deferred_init_memmap_chunk+0x560/0x688 deferred_grow_zone+0x190/0x278 _deferred_grow_zone+0x18/0x30 get_page_from_freelist+0x780/0xf78 __alloc_frozen_pages_noprof+0x1dc/0x348 alloc_slab_page+0x30/0x110 allocate_slab+0x98/0x2a0 new_slab+0x4c/0x80 ___slab_alloc+0x5a4/0x770 __slab_alloc.constprop.0+0x88/0x1e0 __kmalloc_node_noprof+0x2c0/0x598 __sdt_alloc+0x3b8/0x728 build_sched_domains+0xe0/0x1260 sched_init_domains+0x14c/0x1c8 sched_init_smp+0x9c/0x1d0 kernel_init_freeable+0x218/0x358 kernel_init+0x28/0x208 ret_from_fork+0x10/0x20 Fix it adding a new argument to deferred_init_memmap_chunk() to explicitly tell it if cond_resched() is allowed or not instead of relying on some current state information which may vary depending on the exact kernel configuration options that are enabled. Link: https://lkml.kernel.org/r/20260122184343.546627-1-longman@redhat.com Fixes: 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") Signed-off-by: Waiman Long <longman@redhat.com> Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: "Paul E . McKenney" <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: <stable@vger.kernrl.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-22 13:43:43 -05:00
mm/mm_init: deferred_grow_zone(): fix out-of-range first_deferred_pfn With CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled, deferred_grow_zone() initializes struct pages early in boot to satisfy an allocation. With a large CMA reservation in place, the ranges deferred_init_memmap() finds may not add up to the allocation it was asked for, and the function ends up initializing the memory map of the entire zone and still falls short. That is fine in itself: the function accounts for it and leaves the caller to decide whether it now has enough memory. However, the update of pgdat->first_deferred_pfn that tracks where uninitialized memory map starts could overflow. If the node's RAM end is not aligned on PAGES_PER_SECTION boundaries and some deferred struct pages were initialized, pgdat->first_deferred_pfn would point past the end of the node's memory. deferred_init_memmap() later picks up from pgdat->first_deferred_pfn and hits a BUG_ON(), because it expects a pfn within its node. For example, when running a kernel with CONFIG_DEFERRED_STRUCT_PAGE_INIT=y and CONFIG_CMA=y using the following qemu command line qemu-system-x86_64 -enable-kvm -m 8032M -kernel bzImage \ -append "nokaslr cma=4768M@0x100000000" the kernel panics: kernel BUG at mm/mm_init.c:2131! CPU: 3 UID: 0 PID: 36 Comm: pgdatinit0 Not tainted 7.2.0-rc6 #1 RIP: 0010:deferred_init_memmap+0x1b8/0x1c0 RAX: 0000000000236000 R13: 0000000000238000 Call Trace: kthread+0xdf/0x120 ret_from_fork+0x187/0x250 Make sure that the update of pgdta->first_deferred_pfn does not overflow when the entire zone's (and therefore node's) memory map is initialized. Fixes: 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") Cc: stable@vger.kernel.org Assisted-by: Kiro:claude-opus-5 Signed-off-by: Alexander Graf <graf@amazon.com> Link: https://patch.msgid.link/20260807031243.87904-1-graf@amazon.com [rppt: massaged the changelog] Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-08-07 03:12:43 +00:00
mm/mm_init: deferred_grow_zone(): fix out-of-range first_deferred_pfn With CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled, deferred_grow_zone() initializes struct pages early in boot to satisfy an allocation. With a large CMA reservation in place, the ranges deferred_init_memmap() finds may not add up to the allocation it was asked for, and the function ends up initializing the memory map of the entire zone and still falls short. That is fine in itself: the function accounts for it and leaves the caller to decide whether it now has enough memory. However, the update of pgdat->first_deferred_pfn that tracks where uninitialized memory map starts could overflow. If the node's RAM end is not aligned on PAGES_PER_SECTION boundaries and some deferred struct pages were initialized, pgdat->first_deferred_pfn would point past the end of the node's memory. deferred_init_memmap() later picks up from pgdat->first_deferred_pfn and hits a BUG_ON(), because it expects a pfn within its node. For example, when running a kernel with CONFIG_DEFERRED_STRUCT_PAGE_INIT=y and CONFIG_CMA=y using the following qemu command line qemu-system-x86_64 -enable-kvm -m 8032M -kernel bzImage \ -append "nokaslr cma=4768M@0x100000000" the kernel panics: kernel BUG at mm/mm_init.c:2131! CPU: 3 UID: 0 PID: 36 Comm: pgdatinit0 Not tainted 7.2.0-rc6 #1 RIP: 0010:deferred_init_memmap+0x1b8/0x1c0 RAX: 0000000000236000 R13: 0000000000238000 Call Trace: kthread+0xdf/0x120 ret_from_fork+0x187/0x250 Make sure that the update of pgdta->first_deferred_pfn does not overflow when the entire zone's (and therefore node's) memory map is initialized. Fixes: 3acb913c9d5b ("mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()") Cc: stable@vger.kernel.org Assisted-by: Kiro:claude-opus-5 Signed-off-by: Alexander Graf <graf@amazon.com> Link: https://patch.msgid.link/20260807031243.87904-1-graf@amazon.com [rppt: massaged the changelog] Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
2026-08-07 03:12:43 +00:00
mm/cma: introduce interface for early reservations It can be desirable to reserve memory in a CMA area before it is activated, early in boot. Such reservations would effectively be memblock allocations, but they can be returned to the CMA area later. This functionality can be used to allow hugetlb bootmem allocations from a hugetlb CMA area. A new interface, cma_reserve_early is introduced. This allows for pageblock-aligned reservations. These reservations are skipped during the initial handoff of pages in a CMA area to the buddy allocator. The caller is responsible for making sure that the page structures are set up, and that the migrate type is set correctly, as with other memblock allocations that stick around. If the CMA area fails to activate (because it intersects with multiple zones), the reserved memory is not given to the buddy allocator, the caller needs to take care of that. Link: https://lkml.kernel.org/r/20250228182928.2645936-25-fvdl@google.com Signed-off-by: Frank van der Linden <fvdl@google.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-28 18:29:25 +00:00
mm/cma: introduce interface for early reservations It can be desirable to reserve memory in a CMA area before it is activated, early in boot. Such reservations would effectively be memblock allocations, but they can be returned to the CMA area later. This functionality can be used to allow hugetlb bootmem allocations from a hugetlb CMA area. A new interface, cma_reserve_early is introduced. This allows for pageblock-aligned reservations. These reservations are skipped during the initial handoff of pages in a CMA area to the buddy allocator. The caller is responsible for making sure that the page structures are set up, and that the migrate type is set correctly, as with other memblock allocations that stick around. If the CMA area fails to activate (because it intersects with multiple zones), the reserved memory is not given to the buddy allocator, the caller needs to take care of that. Link: https://lkml.kernel.org/r/20250228182928.2645936-25-fvdl@google.com Signed-off-by: Frank van der Linden <fvdl@google.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-28 18:29:25 +00:00
mm/hugetlb: check bootmem pages for zone intersections Bootmem hugetlb pages are allocated using memblock, which isn't (and mostly can't be) aware of zones. So, they may end up crossing zone boundaries. This would create confusion, a hugetlb page that is part of multiple zones is bad. Worse, HVO might then end up stealthily re-assigning pages to a different zone when a hugetlb page is freed, since the tail page structures beyond the first vmemmap page would inherit the zone of the first page structures. While the chance of this happening is low, you can definitely create a configuration where this happens (especially using ZONE_MOVABLE). To avoid this issue, check if bootmem hugetlb pages intersect with multiple zones during the gather phase, and discard them, handing them to the page allocator, if they do. Record the number of invalid bootmem pages per node and subtract them from the number of available pages at the end, making it easier to do these checks in multiple places later on. Link: https://lkml.kernel.org/r/20250228182928.2645936-14-fvdl@google.com Signed-off-by: Frank van der Linden <fvdl@google.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-28 18:29:14 +00:00
mm/hugetlb: initialize gigantic bootmem hugepage struct pages earlier Gigantic bootmem HugeTLB pages are currently initialized from hugetlb_init(), but page_alloc_init_late() runs earlier and walks pageblocks to determine zone contiguity. If a bootmem HugeTLB region is marked noinit, set_zone_contiguous() can observe still-uninitialized struct pages through __pageblock_pfn_to_page(). This may not trigger an immediate failure, but it can make set_zone_contiguous() compute the wrong zone contiguity state. If extra poisoned-page checks are added in this path, such as PF_POISONED_CHECK() in page_zone_id(), it can also trigger an early boot panic. Initialize gigantic bootmem HugeTLB struct pages from page_alloc_init_late(), before zone contiguity is evaluated, so later page allocator setup only sees valid struct page state. This also makes the initialization order more natural, as struct pages should be initialized before later code inspects them. Link: https://lore.kernel.org/20260612035903.2468601-5-songmuchun@bytedance.com Fixes: fde1c4ecf916 ("mm: hugetlb: skip initialization of gigantic tail struct pages if freed by HVO") Signed-off-by: Muchun Song <songmuchun@bytedance.com> Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Oscar Salvador <osalvador@suse.de> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: David Hildenbrand <david@kernel.org> Cc: Frank van der Linden <fvdl@google.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador (SUSE) <osalvador@kernel.org> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Usama Arif <usama.arif@linux.dev> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-06-12 11:58:48 +08:00
mm: pass meminit_context to __free_pages_core() Patch series "mm/memory_hotplug: use PageOffline() instead of PageReserved() for !ZONE_DEVICE". This can be a considered a long-overdue follow-up to some parts of [1]. The patches are based on [2], but they are not strictly required -- just makes it clearer why we can use adjust_managed_page_count() for memory hotplug without going into details about highmem. We stop initializing pages with PageReserved() in memory hotplug code -- except when dealing with ZONE_DEVICE for now. Instead, we use PageOffline(): all pages are initialized to PageOffline() when onlining a memory section, and only the ones actually getting exposed to the system/page allocator will get PageOffline cleared. This way, we enlighten memory hotplug more about PageOffline() pages and can cleanup some hacks we have in virtio-mem code. What about ZONE_DEVICE? PageOffline() is wrong, but we might just stop using PageReserved() for them later by simply checking for is_zone_device_page() at suitable places. That will be a separate patch set / proposal. This primarily affects virtio-mem, HV-balloon and XEN balloon. I only briefly tested with virtio-mem, which benefits most from these cleanups. [1] https://lore.kernel.org/all/20191024120938.11237-1-david@redhat.com/ [2] https://lkml.kernel.org/r/20240607083711.62833-1-david@redhat.com This patch (of 3): In preparation for further changes, let's teach __free_pages_core() about the differences of memory hotplug handling. Move the memory hotplug specific handling from generic_online_page() to __free_pages_core(), use adjust_managed_page_count() on the memory hotplug path, and spell out why memory freed via memblock cannot currently use adjust_managed_page_count(). [david@redhat.com: add missed CONFIG_DEFERRED_STRUCT_PAGE_INIT] Link: https://lkml.kernel.org/r/b72e6efd-fb0a-459c-b1a0-88a98e5b19e2@redhat.com [david@redhat.com: fix up the memblock comment, per Oscar] Link: https://lkml.kernel.org/r/2ed64218-7f3b-4302-a5dc-27f060654fe2@redhat.com [david@redhat.com: add the parameter name also in the declaration] Link: https://lkml.kernel.org/r/ca575956-f0dd-4fb9-a307-6b7621681ed9@redhat.com Link: https://lkml.kernel.org/r/20240607090939.89524-1-david@redhat.com Link: https://lkml.kernel.org/r/20240607090939.89524-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dexuan Cui <decui@microsoft.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eugenio Pérez <eperezma@redhat.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Cc: Jason Wang <jasowang@redhat.com> Cc: Juergen Gross <jgross@suse.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Marco Elver <elver@google.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Oleksandr Tyshchenko <oleksandr_tyshchenko@epam.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Wei Liu <wei.liu@kernel.org> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-07 11:09:36 +02:00
Revert "mm: init_mlocked_on_free_v3" There was insufficient review and no agreement that this is the right approach. There are serious flaws with the implementation that make processes using mlock() not even work with simple fork() [1] and we get reliable crashes when rebooting. Further, simply because we might be unmapping a single PTE of a large mlocked folio, we shouldn't zero out the whole folio. ... especially because the code can also *corrupt* urelated memory because kernel_init_pages(page, folio_nr_pages(folio)); Could end up writing outside of the actual folio if we work with a tail page. Let's revert it. Once there is agreement that this is the right approach, the issues were fixed and there was reasonable review and proper testing, we can consider it again. [1] https://lkml.kernel.org/r/4da9da2f-73e4-45fd-b62f-a8a513314057@redhat.com Link: https://lkml.kernel.org/r/20240605091710.38961-1-david@redhat.com Fixes: ba42b524a040 ("mm: init_mlocked_on_free_v3") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: David Wang <00107082@163.com> Closes: https://lore.kernel.org/lkml/20240528151340.4282-1-00107082@163.com/ Reported-by: Lance Yang <ioworker0@gmail.com> Closes: https://lkml.kernel.org/r/20240601140917.43562-1-ioworker0@gmail.com Acked-by: Lance Yang <ioworker0@gmail.com> Cc: York Jasper Niebuhr <yjnworkstation@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-05 11:17:10 +02:00
Revert "mm: init_mlocked_on_free_v3" There was insufficient review and no agreement that this is the right approach. There are serious flaws with the implementation that make processes using mlock() not even work with simple fork() [1] and we get reliable crashes when rebooting. Further, simply because we might be unmapping a single PTE of a large mlocked folio, we shouldn't zero out the whole folio. ... especially because the code can also *corrupt* urelated memory because kernel_init_pages(page, folio_nr_pages(folio)); Could end up writing outside of the actual folio if we work with a tail page. Let's revert it. Once there is agreement that this is the right approach, the issues were fixed and there was reasonable review and proper testing, we can consider it again. [1] https://lkml.kernel.org/r/4da9da2f-73e4-45fd-b62f-a8a513314057@redhat.com Link: https://lkml.kernel.org/r/20240605091710.38961-1-david@redhat.com Fixes: ba42b524a040 ("mm: init_mlocked_on_free_v3") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: David Wang <00107082@163.com> Closes: https://lore.kernel.org/lkml/20240528151340.4282-1-00107082@163.com/ Reported-by: Lance Yang <ioworker0@gmail.com> Closes: https://lkml.kernel.org/r/20240601140917.43562-1-ioworker0@gmail.com Acked-by: Lance Yang <ioworker0@gmail.com> Cc: York Jasper Niebuhr <yjnworkstation@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-05 11:17:10 +02:00
Revert "mm: init_mlocked_on_free_v3" There was insufficient review and no agreement that this is the right approach. There are serious flaws with the implementation that make processes using mlock() not even work with simple fork() [1] and we get reliable crashes when rebooting. Further, simply because we might be unmapping a single PTE of a large mlocked folio, we shouldn't zero out the whole folio. ... especially because the code can also *corrupt* urelated memory because kernel_init_pages(page, folio_nr_pages(folio)); Could end up writing outside of the actual folio if we work with a tail page. Let's revert it. Once there is agreement that this is the right approach, the issues were fixed and there was reasonable review and proper testing, we can consider it again. [1] https://lkml.kernel.org/r/4da9da2f-73e4-45fd-b62f-a8a513314057@redhat.com Link: https://lkml.kernel.org/r/20240605091710.38961-1-david@redhat.com Fixes: ba42b524a040 ("mm: init_mlocked_on_free_v3") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: David Wang <00107082@163.com> Closes: https://lore.kernel.org/lkml/20240528151340.4282-1-00107082@163.com/ Reported-by: Lance Yang <ioworker0@gmail.com> Closes: https://lkml.kernel.org/r/20240601140917.43562-1-ioworker0@gmail.com Acked-by: Lance Yang <ioworker0@gmail.com> Cc: York Jasper Niebuhr <yjnworkstation@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-05 11:17:10 +02:00
Revert "mm: init_mlocked_on_free_v3" There was insufficient review and no agreement that this is the right approach. There are serious flaws with the implementation that make processes using mlock() not even work with simple fork() [1] and we get reliable crashes when rebooting. Further, simply because we might be unmapping a single PTE of a large mlocked folio, we shouldn't zero out the whole folio. ... especially because the code can also *corrupt* urelated memory because kernel_init_pages(page, folio_nr_pages(folio)); Could end up writing outside of the actual folio if we work with a tail page. Let's revert it. Once there is agreement that this is the right approach, the issues were fixed and there was reasonable review and proper testing, we can consider it again. [1] https://lkml.kernel.org/r/4da9da2f-73e4-45fd-b62f-a8a513314057@redhat.com Link: https://lkml.kernel.org/r/20240605091710.38961-1-david@redhat.com Fixes: ba42b524a040 ("mm: init_mlocked_on_free_v3") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: David Wang <00107082@163.com> Closes: https://lore.kernel.org/lkml/20240528151340.4282-1-00107082@163.com/ Reported-by: Lance Yang <ioworker0@gmail.com> Closes: https://lkml.kernel.org/r/20240601140917.43562-1-ioworker0@gmail.com Acked-by: Lance Yang <ioworker0@gmail.com> Cc: York Jasper Niebuhr <yjnworkstation@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-06-05 11:17:10 +02:00
mm: cache struct page for empty_zero_page and return it from ZERO_PAGE() For most architectures every invocation of ZERO_PAGE() does virt_to_page(empty_zero_page). But empty_zero_page is in BSS and it is enough to get its struct page once at initialization time and then use it whenever a zero page should be accessed. Add yet another __zero_page variable that will be initialized as virt_to_page(empty_zero_page) for most architectures in a weak arch_setup_zero_pages() function. For architectures that use colored zero pages (MIPS and s390) rename their setup_zero_pages() to arch_setup_zero_pages() and make it global rather than static. For architectures that cannot use virt_to_page() for BSS (arm64 and sparc64) add override of arch_setup_zero_pages(). Link: https://lkml.kernel.org/r/20260211103141.3215197-5-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-11 12:31:41 +02:00
mm: don't special case !MMU for is_zero_pfn() and my_zero_pfn() Patch series "arch, mm: consolidate empty_zero_page", v3. These patches cleanup handling of ZERO_PAGE() and zero_pfn. This patch (of 4): nommu architectures have empty_zero_page and define ZERO_PAGE() and although they don't really use it to populate page tables, there is no reason to hardwire !MMU implementation of is_zero_pfn() and my_zero_pfn() to 0. Drop #ifdef CONFIG_MMU around implementations of is_zero_pfn() and my_zero_pfn() and remove !MMU version. While on it, make zero_pfn __ro_after_init. Link: https://lkml.kernel.org/r/20260211103141.3215197-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20260211103141.3215197-2-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-11 12:31:38 +02:00
mm: cache struct page for empty_zero_page and return it from ZERO_PAGE() For most architectures every invocation of ZERO_PAGE() does virt_to_page(empty_zero_page). But empty_zero_page is in BSS and it is enough to get its struct page once at initialization time and then use it whenever a zero page should be accessed. Add yet another __zero_page variable that will be initialized as virt_to_page(empty_zero_page) for most architectures in a weak arch_setup_zero_pages() function. For architectures that use colored zero pages (MIPS and s390) rename their setup_zero_pages() to arch_setup_zero_pages() and make it global rather than static. For architectures that cannot use virt_to_page() for BSS (arm64 and sparc64) add override of arch_setup_zero_pages(). Link: https://lkml.kernel.org/r/20260211103141.3215197-5-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-11 12:31:41 +02:00
mm: rename my_zero_pfn() to zero_pfn() my_zero_pfn() is a silly name. Rename zero_pfn variable to zero_page_pfn and my_zero_pfn() function to zero_pfn(). While on it, move extern declarations of zero_page_pfn outside the functions that use it and add a comment about what ZERO_PAGE is. Link: https://lkml.kernel.org/r/20260211103141.3215197-3-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-11 12:31:39 +02:00
mm: don't special case !MMU for is_zero_pfn() and my_zero_pfn() Patch series "arch, mm: consolidate empty_zero_page", v3. These patches cleanup handling of ZERO_PAGE() and zero_pfn. This patch (of 4): nommu architectures have empty_zero_page and define ZERO_PAGE() and although they don't really use it to populate page tables, there is no reason to hardwire !MMU implementation of is_zero_pfn() and my_zero_pfn() to 0. Drop #ifdef CONFIG_MMU around implementations of is_zero_pfn() and my_zero_pfn() and remove !MMU version. While on it, make zero_pfn __ro_after_init. Link: https://lkml.kernel.org/r/20260211103141.3215197-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20260211103141.3215197-2-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-11 12:31:38 +02:00
arch, mm: introduce arch_mm_preinit Currently, implementation of mem_init() in every architecture consists of one or more of the following: * initializations that must run before page allocator is active, for instance swiotlb_init() * a call to memblock_free_all() to release all the memory to the buddy allocator * initializations that must run after page allocator is ready and there is no arch-specific hook other than mem_init() for that, like for example register_page_bootmem_info() in x86 and sparc64 or simple setting of mem_init_done = 1 in several architectures * a bunch of semi-related stuff that apparently had no better place to live, for example a ton of BUILD_BUG_ON()s in parisc. Introduce arch_mm_preinit() that will be the first thing called from mm_core_init(). On architectures that have initializations that must happen before the page allocator is ready, move those into arch_mm_preinit() along with the code that does not depend on ordering with page allocator setup. On several architectures this results in reduction of mem_init() to a single call to memblock_free_all() that allows its consolidation next. Link: https://lkml.kernel.org/r/20250313135003.836600-13-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86] Tested-by: Mark Brown <broonie@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Guo Ren (csky) <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russel King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-13 15:50:02 +02:00
arch, mm: make releasing of memory to page allocator more explicit The point where the memory is released from memblock to the buddy allocator is hidden inside arch-specific mem_init()s and the call to memblock_free_all() is needlessly duplicated in every artiste cure and after introduction of arch_mm_preinit() hook, mem_init() implementation on many architecture only contains the call to memblock_free_all(). Pull memblock_free_all() call into mm_core_init() and drop mem_init() on relevant architectures to make it more explicit where the free memory is released from memblock to the buddy allocator and to reduce code duplication in architecture specific code. Link: https://lkml.kernel.org/r/20250313135003.836600-14-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86] Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Tested-by: Mark Brown <broonie@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Guo Ren (csky) <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russel King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-13 15:50:03 +02:00
arch, mm: consolidate initialization of nodes, zones and memory map To initialize node, zone and memory map data structures every architecture calls free_area_init() during setup_arch() and passes it an array of zone limits. Beside code duplication it creates "interesting" ordering cases between allocation and initialization of hugetlb and the memory map. Some architectures allocate hugetlb pages very early in setup_arch() in certain cases, some only create hugetlb CMA areas in setup_arch() and sometimes hugetlb allocations happen mm_core_init(). With arch_zone_limits_init() helper available now on all architectures it is no longer necessary to call free_area_init() from architecture setup code. Rather core MM initialization can call arch_zone_limits_init() in a single place. This allows to unify ordering of hugetlb vs memory map allocation and initialization. Remove the call to free_area_init() from architecture specific code and place it in a new mm_core_init_early() function that is called immediately after setup_arch(). After this refactoring it is possible to consolidate hugetlb allocations and eliminate differences in ordering of hugetlb and memory map initialization among different architectures. As the first step of this consolidation move hugetlb_bootmem_alloc() to mm_core_early_init(). Link: https://lkml.kernel.org/r/20260111082105.290734-24-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alex Shi <alexs@kernel.org> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Klara Modin <klarasmodin@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-11 10:20:57 +02:00
mm, arch: consolidate hugetlb CMA reservation Every architecture that supports hugetlb_cma command line parameter reserves CMA areas for hugetlb during setup_arch(). This obfuscates the ordering of hugetlb CMA initialization with respect to the rest initialization of the core MM. Introduce arch_hugetlb_cma_order() callback to allow architectures report the desired order-per-bit of CMA areas and provide a week implementation of arch_hugetlb_cma_order() for architectures that don't support hugetlb with CMA. Use this callback in hugetlb_cma_reserve() instead if passing the order as parameter and call hugetlb_cma_reserve() from mm_core_init_early() rather than have it spread over architecture specific code. Link: https://lkml.kernel.org/r/20260111082105.290734-28-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alex Shi <alexs@kernel.org> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Klara Modin <klarasmodin@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-11 10:21:01 +02:00
arch, mm: consolidate initialization of nodes, zones and memory map To initialize node, zone and memory map data structures every architecture calls free_area_init() during setup_arch() and passes it an array of zone limits. Beside code duplication it creates "interesting" ordering cases between allocation and initialization of hugetlb and the memory map. Some architectures allocate hugetlb pages very early in setup_arch() in certain cases, some only create hugetlb CMA areas in setup_arch() and sometimes hugetlb allocations happen mm_core_init(). With arch_zone_limits_init() helper available now on all architectures it is no longer necessary to call free_area_init() from architecture setup code. Rather core MM initialization can call arch_zone_limits_init() in a single place. This allows to unify ordering of hugetlb vs memory map allocation and initialization. Remove the call to free_area_init() from architecture specific code and place it in a new mm_core_init_early() function that is called immediately after setup_arch(). After this refactoring it is possible to consolidate hugetlb allocations and eliminate differences in ordering of hugetlb and memory map initialization among different architectures. As the first step of this consolidation move hugetlb_bootmem_alloc() to mm_core_early_init(). Link: https://lkml.kernel.org/r/20260111082105.290734-24-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alex Shi <alexs@kernel.org> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Klara Modin <klarasmodin@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-11 10:20:57 +02:00
2026-06-12 11:58:52 +08:00
arch, mm: consolidate initialization of nodes, zones and memory map To initialize node, zone and memory map data structures every architecture calls free_area_init() during setup_arch() and passes it an array of zone limits. Beside code duplication it creates "interesting" ordering cases between allocation and initialization of hugetlb and the memory map. Some architectures allocate hugetlb pages very early in setup_arch() in certain cases, some only create hugetlb CMA areas in setup_arch() and sometimes hugetlb allocations happen mm_core_init(). With arch_zone_limits_init() helper available now on all architectures it is no longer necessary to call free_area_init() from architecture setup code. Rather core MM initialization can call arch_zone_limits_init() in a single place. This allows to unify ordering of hugetlb vs memory map allocation and initialization. Remove the call to free_area_init() from architecture specific code and place it in a new mm_core_init_early() function that is called immediately after setup_arch(). After this refactoring it is possible to consolidate hugetlb allocations and eliminate differences in ordering of hugetlb and memory map initialization among different architectures. As the first step of this consolidation move hugetlb_bootmem_alloc() to mm_core_early_init(). Link: https://lkml.kernel.org/r/20260111082105.290734-24-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alex Shi <alexs@kernel.org> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@kernel.org> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Klara Modin <klarasmodin@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Pratyush Yadav <pratyush@kernel.org> Cc: Richard Weinberger <richard@nod.at> Cc: "Ritesh Harjani (IBM)" <ritesh.list@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-11 10:20:57 +02:00
arch, mm: introduce arch_mm_preinit Currently, implementation of mem_init() in every architecture consists of one or more of the following: * initializations that must run before page allocator is active, for instance swiotlb_init() * a call to memblock_free_all() to release all the memory to the buddy allocator * initializations that must run after page allocator is ready and there is no arch-specific hook other than mem_init() for that, like for example register_page_bootmem_info() in x86 and sparc64 or simple setting of mem_init_done = 1 in several architectures * a bunch of semi-related stuff that apparently had no better place to live, for example a ton of BUILD_BUG_ON()s in parisc. Introduce arch_mm_preinit() that will be the first thing called from mm_core_init(). On architectures that have initializations that must happen before the page allocator is ready, move those into arch_mm_preinit() along with the code that does not depend on ordering with page allocator setup. On several architectures this results in reduction of mem_init() to a single call to memblock_free_all() that allows its consolidation next. Link: https://lkml.kernel.org/r/20250313135003.836600-13-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86] Tested-by: Mark Brown <broonie@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Guo Ren (csky) <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russel King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-13 15:50:02 +02:00
mm: cache struct page for empty_zero_page and return it from ZERO_PAGE() For most architectures every invocation of ZERO_PAGE() does virt_to_page(empty_zero_page). But empty_zero_page is in BSS and it is enough to get its struct page once at initialization time and then use it whenever a zero page should be accessed. Add yet another __zero_page variable that will be initialized as virt_to_page(empty_zero_page) for most architectures in a weak arch_setup_zero_pages() function. For architectures that use colored zero pages (MIPS and s390) rename their setup_zero_pages() to arch_setup_zero_pages() and make it global rather than static. For architectures that cannot use virt_to_page() for BSS (arm64 and sparc64) add override of arch_setup_zero_pages(). Link: https://lkml.kernel.org/r/20260211103141.3215197-5-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-11 12:31:41 +02:00
mm/hugetlb: convert cmdline parameters from setup to early Convert the cmdline parameters (hugepagesz, hugepages, default_hugepagesz and hugetlb_free_vmemmap) to early parameters. Since parse_early_param might run before MMU setups on some platforms (powerpc), validation of huge page sizes as specified in command line parameters would fail. So instead, for the hstate-related values, just record the them and parse them on demand, from hugetlb_bootmem_alloc. The allocation of hugetlb bootmem pages is now done in hugetlb_bootmem_alloc, which is called explicitly at the start of mm_core_init(). core_initcall would be too late, as that happens with memblock already torn down. This change will allow earlier allocation and initialization of bootmem hugetlb pages later on. No functional change intended. Link: https://lkml.kernel.org/r/20250228182928.2645936-8-fvdl@google.com Signed-off-by: Frank van der Linden <fvdl@google.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Joao Martins <joao.m.martins@oracle.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-28 18:29:08 +00:00
alloc_tag: support for page allocation tag compression Implement support for storing page allocation tag references directly in the page flags instead of page extensions. sysctl.vm.mem_profiling boot parameter it extended to provide a way for a user to request this mode. Enabling compression eliminates memory overhead caused by page_ext and results in better performance for page allocations. However this mode will not work if the number of available page flag bits is insufficient to address all kernel allocations. Such condition can happen during boot or when loading a module. If this condition is detected, memory allocation profiling gets disabled with an appropriate warning. By default compression mode is disabled. Link: https://lkml.kernel.org/r/20241023170759.999909-7-surenb@google.com Signed-off-by: Suren Baghdasaryan <surenb@google.com> Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov (AMD) <bp@alien8.de> Cc: Christoph Hellwig <hch@infradead.org> Cc: Daniel Gomez <da.gomez@samsung.com> Cc: David Hildenbrand <david@redhat.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: David Rientjes <rientjes@google.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Luis Chamberlain <mcgrof@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Minchan Kim <minchan@google.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Petr Pavlu <petr.pavlu@suse.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sami Tolvanen <samitolvanen@google.com> Cc: Sourav Panda <souravpanda@google.com> Cc: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Thomas Huth <thuth@redhat.com> Cc: Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xiongwei Song <xiongwei.song@windriver.com> Cc: Yu Zhao <yuzhao@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-10-23 10:07:59 -07:00
kexec: add Kexec HandOver (KHO) generation helpers Add the infrastructure to generate Kexec HandOver metadata. Kexec HandOver is a mechanism that allows Linux to preserve state - arbitrary properties as well as memory locations - across kexec. It does so using 2 concepts: 1) KHO FDT - Every KHO kexec carries a KHO specific flattened device tree blob that describes preserved memory regions. Device drivers can register to KHO to serialize and preserve their states before kexec. 2) Scratch Regions - CMA regions that we allocate in the first kernel. CMA gives us the guarantee that no handover pages land in those regions, because handover pages must be at a static physical memory location. We use these regions as the place to load future kexec images so that they won't collide with any handover data. Link: https://lkml.kernel.org/r/20250509074635.3187114-5-changyuanl@google.com Signed-off-by: Alexander Graf <graf@amazon.com> Co-developed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Co-developed-by: Pratyush Yadav <ptyadav@amazon.de> Signed-off-by: Pratyush Yadav <ptyadav@amazon.de> Co-developed-by: Changyuan Lyu <changyuanl@google.com> Signed-off-by: Changyuan Lyu <changyuanl@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Anthony Yznaga <anthony.yznaga@oracle.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Ashish Kalra <ashish.kalra@amd.com> Cc: Ben Herrenschmidt <benh@kernel.crashing.org> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Gowans <jgowans@amazon.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Krzysztof Kozlowski <krzk@kernel.org> Cc: Marc Rutland <mark.rutland@arm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rob Herring <robh@kernel.org> Cc: Saravana Kannan <saravanak@google.com> Cc: Stanislav Kinsburskii <skinsburskii@linux.microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Thomas Lendacky <thomas.lendacky@amd.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-09 00:46:22 -07:00
arch, mm: make releasing of memory to page allocator more explicit The point where the memory is released from memblock to the buddy allocator is hidden inside arch-specific mem_init()s and the call to memblock_free_all() is needlessly duplicated in every artiste cure and after introduction of arch_mm_preinit() hook, mem_init() implementation on many architecture only contains the call to memblock_free_all(). Pull memblock_free_all() call into mm_core_init() and drop mem_init() on relevant architectures to make it more explicit where the free memory is released from memblock to the buddy allocator and to reduce code duplication in architecture specific code. Link: https://lkml.kernel.org/r/20250313135003.836600-14-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> [x86] Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> [m68k] Tested-by: Mark Brown <broonie@kernel.org> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Betkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Guo Ren (csky) <guoren@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiaxun Yang <jiaxun.yang@flygoat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russel King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Thomas Gleinxer <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-13 15:50:03 +02:00