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1,105,074 commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Marcelo Tosatti
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ff042f4a9b |
mm: lru_cache_disable: replace work queue synchronization with synchronize_rcu
On systems that run FIFO:1 applications that busy loop, any SCHED_OTHER
task that attempts to execute on such a CPU (such as work threads) will
not be scheduled, which leads to system hangs.
Commit
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Waiman Long
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405cc51fc1 |
mm/list_lru: optimize memcg_reparent_list_lru_node()
Since commit
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Hugh Dickins
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89f6c88a6a |
mm: __isolate_lru_page_prepare() in isolate_migratepages_block()
__isolate_lru_page_prepare() conflates two unrelated functions, with the flags to one disjoint from the flags to the other; and hides some of the important checks outside of isolate_migratepages_block(), where the sequence is better to be visible. It comes from the days of lumpy reclaim, before compaction, when the combination made more sense. Move what's needed by mm/compaction.c isolate_migratepages_block() inline there, and what's needed by mm/vmscan.c isolate_lru_pages() inline there. Shorten "isolate_mode" to "mode", so the sequence of conditions is easier to read. Declare a "mapping" variable, to save one call to page_mapping() (but not another: calling again after page is locked is necessary). Simplify isolate_lru_pages() with a "move_to" list pointer. Link: https://lkml.kernel.org/r/879d62a8-91cc-d3c6-fb3b-69768236df68@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Alex Shi <alexs@kernel.org> Cc: Alexander Duyck <alexander.duyck@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Hugh Dickins
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b698f0a177 |
mm/fs: delete PF_SWAPWRITE
PF_SWAPWRITE has been redundant since v3.2 commit
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Guo Zhengkui
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d794103d52 |
userfaultfd/selftests: fix uninitialized_var.cocci warning
Fix following coccicheck warning: tools/testing/selftests/vm/userfaultfd.c:556:23-24: WARNING this kind of initialization is deprecated `unsigned long page_nr = *(&page_nr)` has the same form of uninitialized_var() macro. I remove the redundant assignement. It has been tested with gcc (Debian 8.3.0-6) 8.3.0. The patch which removed uninitialized_var() is: https://lore.kernel.org/all/20121028102007.GA7547@gmail.com/ And there is very few "/* GCC */" comments in the Linux kernel code now. Link: https://lkml.kernel.org/r/20220304082333.9252-1-guozhengkui@vivo.com Signed-off-by: Guo Zhengkui <guozhengkui@vivo.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Nadav Amit
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824ddc601a |
userfaultfd: provide unmasked address on page-fault
Userfaultfd is supposed to provide the full address (i.e., unmasked) of
the faulting access back to userspace. However, that is not the case for
quite some time.
Even running "userfaultfd_demo" from the userfaultfd man page provides the
wrong output (and contradicts the man page). Notice that
"UFFD_EVENT_PAGEFAULT event" shows the masked address (7fc5e30b3000) and
not the first read address (0x7fc5e30b300f).
Address returned by mmap() = 0x7fc5e30b3000
fault_handler_thread():
poll() returns: nready = 1; POLLIN = 1; POLLERR = 0
UFFD_EVENT_PAGEFAULT event: flags = 0; address = 7fc5e30b3000
(uffdio_copy.copy returned 4096)
Read address 0x7fc5e30b300f in main(): A
Read address 0x7fc5e30b340f in main(): A
Read address 0x7fc5e30b380f in main(): A
Read address 0x7fc5e30b3c0f in main(): A
The exact address is useful for various reasons and specifically for
prefetching decisions. If it is known that the memory is populated by
certain objects whose size is not page-aligned, then based on the faulting
address, the uffd-monitor can decide whether to prefetch and prefault the
adjacent page.
This bug has been for quite some time in the kernel: since commit
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Miaohe Lin
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87d2762e22 |
mm: remove unneeded local variable follflags
We can pass FOLL_GET | FOLL_DUMP to follow_page directly to simplify the code a bit in add_page_for_migration and split_huge_pages_pid. Link: https://lkml.kernel.org/r/20220311072002.35575-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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David Howells
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4e936ecc01 |
mm/hugetlb.c: export PageHeadHuge()
Export PageHeadHuge() - it's used by folio_test_hugetlb() and thence by such as folio_file_page() and folio_contains(). Matthew suggested I use the first of those instead of doing the same calculation manually - but I can't call it from a module. Kirill suggested rearranging things to put it in a header, but that introduces header dependencies because of where constants are defined. [akpm@linux-foundation.org: s/EXPORT_SYMBOL/EXPORT_SYMBOL_GPL/, per Christoph] Link: https://lkml.kernel.org/r/2494562.1646054576@warthog.procyon.org.uk Link: https://lore.kernel.org/r/163707085314.3221130.14783857863702203440.stgit@warthog.procyon.org.uk/ Signed-off-by: David Howells <dhowells@redhat.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Christoph Hellwig <hch@infradead.org> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Miaohe Lin
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98bc26ac77 |
mm/hugetlb: use helper macro __ATTR_RW
Use helper macro __ATTR_RW to define HSTATE_ATTR to make code more clear. Minor readability improvement. Link: https://lkml.kernel.org/r/20220222112731.33479-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mike Kravetz
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f9317f77a6 |
hugetlb: clean up potential spectre issue warnings
Recently introduced code allows numa nodes to be specified on the kernel command line for hugetlb allocations or CMA reservations. The node values are user specified and used as indicies into arrays. This generated the following smatch warnings: mm/hugetlb.c:4170 hugepages_setup() warn: potential spectre issue 'default_hugepages_in_node' [w] mm/hugetlb.c:4172 hugepages_setup() warn: potential spectre issue 'parsed_hstate->max_huge_pages_node' [w] mm/hugetlb.c:6898 cmdline_parse_hugetlb_cma() warn: potential spectre issue 'hugetlb_cma_size_in_node' [w] (local cap) Clean up by using array_index_nospec to sanitize array indicies. The routine cmdline_parse_hugetlb_cma has the same overflow/truncation issue addressed in [1]. That is also fixed with this change. [1] https://lore.kernel.org/linux-mm/20220209134018.8242-1-liuyuntao10@huawei.com/ As Michal pointed out, this is unlikely to be exploitable because it is __init code. But the patch suppresses the warnings. [mike.kravetz@oracle.com: v2] Link: https://lkml.kernel.org/r/20220218212946.35441-1-mike.kravetz@oracle.com Link: https://lkml.kernel.org/r/20220217234218.192885-1-mike.kravetz@oracle.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Zhenguo Yao <yaozhenguo1@gmail.com> Cc: Liu Yuntao <liuyuntao10@huawei.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Anshuman Khandual
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07431506e8 |
mm/hugetlb: generalize ARCH_WANT_GENERAL_HUGETLB
ARCH_WANT_GENERAL_HUGETLB config has duplicate definitions on platforms that subscribe it. Instead make it a generic config option which can be selected on applicable platforms when required. Link: https://lkml.kernel.org/r/1643718465-4324-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Muchun Song
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e540841734 |
mm: sparsemem: move vmemmap related to HugeTLB to CONFIG_HUGETLB_PAGE_FREE_VMEMMAP
The vmemmap_remap_free/alloc are relevant to HugeTLB, so move those functiongs to the scope of CONFIG_HUGETLB_PAGE_FREE_VMEMMAP. Link: https://lkml.kernel.org/r/20211101031651.75851-6-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Barry Song <song.bao.hua@hisilicon.com> Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com> Cc: Chen Huang <chenhuang5@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Fam Zheng <fam.zheng@bytedance.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Muchun Song
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b147c89cd4 |
selftests: vm: add a hugetlb test case
Since the head vmemmap page frame associated with each HugeTLB page is reused, we should hide the PG_head flag of tail struct page from the user. Add a tese case to check whether it is work properly. The test steps are as follows. 1) alloc 2MB hugeTLB 2) get each page frame 3) apply those APIs in each page frame 4) Those APIs work completely the same as before. Reading the flags of a page by /proc/kpageflags is done in stable_page_flags(), which has invoked PageHead(), PageTail(), PageCompound() and compound_head(). If those APIs work properly, the head page must have 15 and 17 bits set. And tail pages must have 16 and 17 bits set but 15 bit unset. Those flags are checked in check_page_flags(). Link: https://lkml.kernel.org/r/20211101031651.75851-5-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Barry Song <song.bao.hua@hisilicon.com> Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com> Cc: Chen Huang <chenhuang5@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Fam Zheng <fam.zheng@bytedance.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Muchun Song
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d8d55f5616 |
mm: sparsemem: use page table lock to protect kernel pmd operations
The init_mm.page_table_lock is used to protect kernel page tables, we can use it to serialize splitting vmemmap PMD mappings instead of mmap write lock, which can increase the concurrency of vmemmap_remap_free(). Actually, It increase the concurrency between allocations of HugeTLB pages. But it is not the only benefit. There are a lot of users of mmap read lock of init_mm. The mmap write lock is holding through vmemmap_remap_free(), removing mmap write lock usage to make it does not affect other users of mmap read lock. It is not making anything worse and always a win to move. Now the kernel page table walker does not hold the page_table_lock when walking pmd entries. There may be consistency issue of a pmd entry, because pmd entry might change from a huge pmd entry to a PTE page table. There is only one user of kernel page table walker, namely ptdump. The ptdump already considers the consistency, which use a local variable to cache the value of pmd entry. But we also need to update ->action to ACTION_CONTINUE to make sure the walker does not walk every pte entry again when concurrent thread has split the huge pmd. Link: https://lkml.kernel.org/r/20211101031651.75851-4-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Cc: Barry Song <song.bao.hua@hisilicon.com> Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com> Cc: Chen Huang <chenhuang5@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Fam Zheng <fam.zheng@bytedance.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Muchun Song
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a6b40850c4 |
mm: hugetlb: replace hugetlb_free_vmemmap_enabled with a static_key
The page_fixed_fake_head() is used throughout memory management and the conditional check requires checking a global variable, although the overhead of this check may be small, it increases when the memory cache comes under pressure. Also, the global variable will not be modified after system boot, so it is very appropriate to use static key machanism. Link: https://lkml.kernel.org/r/20211101031651.75851-3-songmuchun@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Reviewed-by: Barry Song <song.bao.hua@hisilicon.com> Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com> Cc: Chen Huang <chenhuang5@huawei.com> Cc: David Hildenbrand <david@redhat.com> Cc: Fam Zheng <fam.zheng@bytedance.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Xiongchun Duan <duanxiongchun@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Muchun Song
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e7d324850b |
mm: hugetlb: free the 2nd vmemmap page associated with each HugeTLB page
Patch series "Free the 2nd vmemmap page associated with each HugeTLB
page", v7.
This series can minimize the overhead of struct page for 2MB HugeTLB
pages significantly. It further reduces the overhead of struct page by
12.5% for a 2MB HugeTLB compared to the previous approach, which means
2GB per 1TB HugeTLB. It is a nice gain. Comments and reviews are
welcome. Thanks.
The main implementation and details can refer to the commit log of patch
1. In this series, I have changed the following four helpers, the
following table shows the impact of the overhead of those helpers.
+------------------+-----------------------+
| APIs | head page | tail page |
+------------------+-----------+-----------+
| PageHead() | Y | N |
+------------------+-----------+-----------+
| PageTail() | Y | N |
+------------------+-----------+-----------+
| PageCompound() | N | N |
+------------------+-----------+-----------+
| compound_head() | Y | N |
+------------------+-----------+-----------+
Y: Overhead is increased.
N: Overhead is _NOT_ increased.
It shows that the overhead of those helpers on a tail page don't change
between "hugetlb_free_vmemmap=on" and "hugetlb_free_vmemmap=off". But the
overhead on a head page will be increased when "hugetlb_free_vmemmap=on"
(except PageCompound()). So I believe that Matthew Wilcox's folio series
will help with this.
The users of PageHead() and PageTail() are much less than compound_head()
and most users of PageTail() are VM_BUG_ON(), so I have done some tests
about the overhead of compound_head() on head pages.
I have tested the overhead of calling compound_head() on a head page,
which is 2.11ns (Measure the call time of 10 million times
compound_head(), and then average).
For a head page whose address is not aligned with PAGE_SIZE or a
non-compound page, the overhead of compound_head() is 2.54ns which is
increased by 20%. For a head page whose address is aligned with
PAGE_SIZE, the overhead of compound_head() is 2.97ns which is increased by
40%. Most pages are the former. I do not think the overhead is
significant since the overhead of compound_head() itself is low.
This patch (of 5):
This patch minimizes the overhead of struct page for 2MB HugeTLB pages
significantly. It further reduces the overhead of struct page by 12.5%
for a 2MB HugeTLB compared to the previous approach, which means 2GB per
1TB HugeTLB (2MB type).
After the feature of "Free sonme vmemmap pages of HugeTLB page" is
enabled, the mapping of the vmemmap addresses associated with a 2MB
HugeTLB page becomes the figure below.
HugeTLB struct pages(8 pages) page frame(8 pages)
+-----------+ ---virt_to_page---> +-----------+ mapping to +-----------+---> PG_head
| | | 0 | -------------> | 0 |
| | +-----------+ +-----------+
| | | 1 | -------------> | 1 |
| | +-----------+ +-----------+
| | | 2 | ----------------^ ^ ^ ^ ^ ^
| | +-----------+ | | | | |
| | | 3 | ------------------+ | | | |
| | +-----------+ | | | |
| | | 4 | --------------------+ | | |
| 2MB | +-----------+ | | |
| | | 5 | ----------------------+ | |
| | +-----------+ | |
| | | 6 | ------------------------+ |
| | +-----------+ |
| | | 7 | --------------------------+
| | +-----------+
| |
| |
| |
+-----------+
As we can see, the 2nd vmemmap page frame (indexed by 1) is reused and
remaped. However, the 2nd vmemmap page frame is also can be freed to
the buddy allocator, then we can change the mapping from the figure
above to the figure below.
HugeTLB struct pages(8 pages) page frame(8 pages)
+-----------+ ---virt_to_page---> +-----------+ mapping to +-----------+---> PG_head
| | | 0 | -------------> | 0 |
| | +-----------+ +-----------+
| | | 1 | ---------------^ ^ ^ ^ ^ ^ ^
| | +-----------+ | | | | | |
| | | 2 | -----------------+ | | | | |
| | +-----------+ | | | | |
| | | 3 | -------------------+ | | | |
| | +-----------+ | | | |
| | | 4 | ---------------------+ | | |
| 2MB | +-----------+ | | |
| | | 5 | -----------------------+ | |
| | +-----------+ | |
| | | 6 | -------------------------+ |
| | +-----------+ |
| | | 7 | ---------------------------+
| | +-----------+
| |
| |
| |
+-----------+
After we do this, all tail vmemmap pages (1-7) are mapped to the head
vmemmap page frame (0). In other words, there are more than one page
struct with PG_head associated with each HugeTLB page. We __know__ that
there is only one head page struct, the tail page structs with PG_head are
fake head page structs. We need an approach to distinguish between those
two different types of page structs so that compound_head(), PageHead()
and PageTail() can work properly if the parameter is the tail page struct
but with PG_head.
The following code snippet describes how to distinguish between real and
fake head page struct.
if (test_bit(PG_head, &page->flags)) {
unsigned long head = READ_ONCE(page[1].compound_head);
if (head & 1) {
if (head == (unsigned long)page + 1)
==> head page struct
else
==> tail page struct
} else
==> head page struct
}
We can safely access the field of the @page[1] with PG_head because the
@page is a compound page composed with at least two contiguous pages.
[songmuchun@bytedance.com: restore lost comment changes]
Link: https://lkml.kernel.org/r/20211101031651.75851-1-songmuchun@bytedance.com
Link: https://lkml.kernel.org/r/20211101031651.75851-2-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Barry Song <song.bao.hua@hisilicon.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Chen Huang <chenhuang5@huawei.com>
Cc: Bodeddula Balasubramaniam <bodeddub@amazon.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Fam Zheng <fam.zheng@bytedance.com>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Miaohe Lin
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5c2a956c3e |
mm/mlock: fix potential imbalanced rlimit ucounts adjustment
user_shm_lock forgets to set allowed to 0 when get_ucounts fails. So
the later user_shm_unlock might do the extra dec_rlimit_ucounts. Fix
this by resetting allowed to 0.
Link: https://lkml.kernel.org/r/20220310132417.41189-1-linmiaohe@huawei.com
Fixes:
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Vlastimil Babka
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1e7a818164 |
mm, fault-injection: declare should_fail_alloc_page()
The mm/ directory can almost fully be built with W=1, which would help in local development. One remaining issue is missing prototype for should_fail_alloc_page(). Thus add it next to the should_failslab() prototype. Note the previous attempt by commit |
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Miaohe Lin
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bf6445bc8f |
mm/memory-failure.c: make non-LRU movable pages unhandlable
We can not really handle non-LRU movable pages in memory failure. Typically they are balloon, zsmalloc, etc. Assuming we run into a base (4K) non-LRU movable page, we could reach as far as identify_page_state(), it should not fall into any category except me_unknown. For the non-LRU compound movable pages, they could be taken for transhuge pages but it's unexpected to split non-LRU movable pages using split_huge_page_to_list in memory_failure. So we could just simply make non-LRU movable pages unhandlable to avoid these possible nasty cases. Link: https://lkml.kernel.org/r/20220312074613.4798-4-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Suggested-by: Yang Shi <shy828301@gmail.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Miaohe Lin
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593396b86e |
mm/memory-failure.c: avoid calling invalidate_inode_page() with unexpected pages
Since commit 042c4f32323b ("mm/truncate: Inline invalidate_complete_page()
into its one caller"), invalidate_inode_page() can invalidate the pages
in the swap cache because the check of page->mapping != mapping is
removed. But invalidate_inode_page() is not expected to deal with the
pages in swap cache. Also non-lru movable page can reach here too.
They're not page cache pages. Skip these pages by checking
PageSwapCache and PageLRU.
Link: https://lkml.kernel.org/r/20220312074613.4798-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Miaohe Lin
|
888af2701d |
mm/memory-failure.c: fix race with changing page compound again
Patch series "A few fixup patches for memory failure", v2. This series contains a few patches to fix the race with changing page compound page, make non-LRU movable pages unhandlable and so on. More details can be found in the respective changelogs. There is a race window where we got the compound_head, the hugetlb page could be freed to buddy, or even changed to another compound page just before we try to get hwpoison page. Think about the below race window: CPU 1 CPU 2 memory_failure_hugetlb struct page *head = compound_head(p); hugetlb page might be freed to buddy, or even changed to another compound page. get_hwpoison_page -- page is not what we want now... If this race happens, just bail out. Also MF_MSG_DIFFERENT_PAGE_SIZE is introduced to record this event. [akpm@linux-foundation.org: s@/**@/*@, per Naoya Horiguchi] Link: https://lkml.kernel.org/r/20220312074613.4798-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220312074613.4798-2-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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luofei
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a06ad3c0c7 |
mm/hwpoison: add in-use hugepage hwpoison filter judgement
After successfully obtaining the reference count of the huge page, it is still necessary to call hwpoison_filter() to make a filter judgement, otherwise the filter hugepage will be unmaped and the related process may be killed. Link: https://lkml.kernel.org/r/20220223082254.2769757-1-luofei@unicloud.com Signed-off-by: luofei <luofei@unicloud.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Borislav Petkov <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: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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luofei
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d1fe111fb6 |
mm/hwpoison: avoid the impact of hwpoison_filter() return value on mce handler
When the hwpoison page meets the filter conditions, it should not be regarded as successful memory_failure() processing for mce handler, but should return a distinct value, otherwise mce handler regards the error page has been identified and isolated, which may lead to calling set_mce_nospec() to change page attribute, etc. Here memory_failure() return -EOPNOTSUPP to indicate that the error event is filtered, mce handler should not take any action for this situation and hwpoison injector should treat as correct. Link: https://lkml.kernel.org/r/20220223082135.2769649-1-luofei@unicloud.com Signed-off-by: luofei <luofei@unicloud.com> Acked-by: Borislav Petkov <bp@suse.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Miaohe Lin
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a581865ecd |
mm/hwpoison-inject: support injecting hwpoison to free page
memory_failure() can handle free buddy page. Support injecting hwpoison to free page by adding is_free_buddy_page check when hwpoison filter is disabled. [akpm@linux-foundation.org: export is_free_buddy_page() to modules] Link: https://lkml.kernel.org/r/20220218092052.3853-1-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Miaohe Lin
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b04d3eebeb |
mm/memory-failure.c: remove unnecessary PageTransTail check
When we reach here, we're guaranteed to have non-compound page as thp is already splited. Remove this unnecessary PageTransTail check. Link: https://lkml.kernel.org/r/20220218090118.1105-9-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Miaohe Lin
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2ab916790f |
mm/memory-failure.c: remove obsolete comment in __soft_offline_page
Since commit
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Miaohe Lin
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357670f79e |
mm/memory-failure.c: rework the try_to_unmap logic in hwpoison_user_mappings()
Only for hugetlb pages in shared mappings, try_to_unmap should take semaphore in write mode here. Rework the code to make it clear. Link: https://lkml.kernel.org/r/20220218090118.1105-7-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Miaohe Lin
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67ff51c6a6 |
mm/memory-failure.c: remove PageSlab check in hwpoison_filter_dev
Since commit
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Miaohe Lin
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75ee64b3c9 |
mm/memory-failure.c: fix race with changing page more robustly
We're only intended to deal with the non-Compound page after we split thp in memory_failure. However, the page could have changed compound pages due to race window. If this happens, we could retry once to hopefully handle the page next round. Also remove unneeded orig_head. It's always equal to the hpage. So we can use hpage directly and remove this redundant one. Link: https://lkml.kernel.org/r/20220218090118.1105-5-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Miaohe Lin
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49775047cf |
mm/memory-failure.c: rework the signaling logic in kill_proc
BUS_MCEERR_AR code is only sent when MF_ACTION_REQUIRED is set and the target is current. Rework the code to make this clear. Link: https://lkml.kernel.org/r/20220218090118.1105-4-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Miaohe Lin
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a994402bc4 |
mm/memory-failure.c: catch unexpected -EFAULT from vma_address()
It's unexpected to walk the page table when vma_address() return
-EFAULT. But dev_pagemap_mapping_shift() is called only when vma
associated to the error page is found already in
collect_procs_{file,anon}, so vma_address() should not return -EFAULT
except with some bug, as Naoya pointed out. We can use VM_BUG_ON_VMA()
to catch this bug here.
Link: https://lkml.kernel.org/r/20220218090118.1105-3-linmiaohe@huawei.com
Signed-off-by: Miaohe Lin <linmiaohe@huawei.com>
Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Miaohe Lin
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577553f489 |
mm/memory-failure.c: minor clean up for memory_failure_dev_pagemap
Patch series "A few cleanup and fixup patches for memory failure", v3. This series contains a few patches to simplify the code logic, remove unneeded variable and remove obsolete comment. Also we fix race changing page more robustly in memory_failure. More details can be found in the respective changelogs. This patch (of 8): The flags always has MF_ACTION_REQUIRED and MF_MUST_KILL set. So we do not need to check these flags again. Link: https://lkml.kernel.org/r/20220218090118.1105-1-linmiaohe@huawei.com Link: https://lkml.kernel.org/r/20220218090118.1105-2-linmiaohe@huawei.com Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Rik van Riel
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e53ac7374e |
mm: invalidate hwpoison page cache page in fault path
Sometimes the page offlining code can leave behind a hwpoisoned clean page cache page. This can lead to programs being killed over and over and over again as they fault in the hwpoisoned page, get killed, and then get re-spawned by whatever wanted to run them. This is particularly embarrassing when the page was offlined due to having too many corrected memory errors. Now we are killing tasks due to them trying to access memory that probably isn't even corrupted. This problem can be avoided by invalidating the page from the page fault handler, which already has a branch for dealing with these kinds of pages. With this patch we simply pretend the page fault was successful if the page was invalidated, return to userspace, incur another page fault, read in the file from disk (to a new memory page), and then everything works again. Link: https://lkml.kernel.org/r/20220212213740.423efcea@imladris.surriel.com Signed-off-by: Rik van Riel <riel@surriel.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Acked-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Naoya Horiguchi
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046545a661 |
mm/hwpoison: fix error page recovered but reported "not recovered"
When an uncorrected memory error is consumed there is a race between the
CMCI from the memory controller reporting an uncorrected error with a
UCNA signature, and the core reporting and SRAR signature machine check
when the data is about to be consumed.
If the CMCI wins that race, the page is marked poisoned when
uc_decode_notifier() calls memory_failure() and the machine check
processing code finds the page already poisoned. It calls
kill_accessing_process() to make sure a SIGBUS is sent. But returns the
wrong error code.
Console log looks like this:
mce: Uncorrected hardware memory error in user-access at 3710b3400
Memory failure: 0x3710b3: recovery action for dirty LRU page: Recovered
Memory failure: 0x3710b3: already hardware poisoned
Memory failure: 0x3710b3: Sending SIGBUS to einj_mem_uc:361438 due to hardware memory corruption
mce: Memory error not recovered
kill_accessing_process() is supposed to return -EHWPOISON to notify that
SIGBUS is already set to the process and kill_me_maybe() doesn't have to
send it again. But current code simply fails to do this, so fix it to
make sure to work as intended. This change avoids the noise message
"Memory error not recovered" and skips duplicate SIGBUSs.
[tony.luck@intel.com: reword some parts of commit message]
Link: https://lkml.kernel.org/r/20220113231117.1021405-1-naoya.horiguchi@linux.dev
Fixes:
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Naoya Horiguchi
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ae483c2006 |
mm/memory-failure.c: remove obsolete comment
With the introduction of mf_mutex, most of memory error handling process is mutually exclusive, so the in-line comment about subtlety about double-checking PageHWPoison is no more correct. So remove it. Link: https://lkml.kernel.org/r/20220125025601.3054511-1-naoya.horiguchi@linux.dev Signed-off-by: Naoya Horiguchi <naoya.horiguchi@nec.com> Suggested-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Mel Gorman
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77fe7f136a |
mm/page_alloc: check high-order pages for corruption during PCP operations
Eric Dumazet pointed out that commit |
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Eric Dumazet
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3313204c8a |
mm/page_alloc: call check_new_pages() while zone spinlock is not held
For high order pages not using pcp, rmqueue() is currently calling the costly check_new_pages() while zone spinlock is held, and hard irqs masked. This is not needed, we can release the spinlock sooner to reduce zone spinlock contention. Note that after this patch, we call __mod_zone_freepage_state() before deciding to leak the page because it is in bad state. Link: https://lkml.kernel.org/r/20220304170215.1868106-1-eric.dumazet@gmail.com Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Suren Baghdasaryan
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fa7fc75f63 |
mm: count time in drain_all_pages during direct reclaim as memory pressure
When page allocation in direct reclaim path fails, the system will make
one attempt to shrink per-cpu page lists and free pages from high alloc
reserves. Draining per-cpu pages into buddy allocator can be a very
slow operation because it's done using workqueues and the task in direct
reclaim waits for all of them to finish before proceeding. Currently
this time is not accounted as psi memory stall.
While testing mobile devices under extreme memory pressure, when
allocations are failing during direct reclaim, we notices that psi
events which would be expected in such conditions were not triggered.
After profiling these cases it was determined that the reason for
missing psi events was that a big chunk of time spent in direct reclaim
is not accounted as memory stall, therefore psi would not reach the
levels at which an event is generated. Further investigation revealed
that the bulk of that unaccounted time was spent inside drain_all_pages
call.
A typical captured case when drain_all_pages path gets activated:
__alloc_pages_slowpath took 44.644.613ns
__perform_reclaim took 751.668ns (1.7%)
drain_all_pages took 43.887.167ns (98.3%)
PSI in this case records the time spent in __perform_reclaim but ignores
drain_all_pages, IOW it misses 98.3% of the time spent in
__alloc_pages_slowpath.
Annotate __alloc_pages_direct_reclaim in its entirety so that delays
from handling page allocation failure in the direct reclaim path are
accounted as memory stall.
Link: https://lkml.kernel.org/r/20220223194812.1299646-1-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reported-by: Tim Murray <timmurray@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Oscar Salvador
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1ca75fa7f1 |
arch/x86/mm/numa: Do not initialize nodes twice
On x86, prior to ("mm: handle uninitialized numa nodes gracecully"), NUMA
nodes could be allocated at three different places.
- numa_register_memblks
- init_cpu_to_node
- init_gi_nodes
All these calls happen at setup_arch, and have the following order:
setup_arch
...
x86_numa_init
numa_init
numa_register_memblks
...
init_cpu_to_node
init_memory_less_node
alloc_node_data
free_area_init_memoryless_node
init_gi_nodes
init_memory_less_node
alloc_node_data
free_area_init_memoryless_node
numa_register_memblks() is only interested in those nodes which have
memory, so it skips over any memoryless node it founds. Later on, when
we have read ACPI's SRAT table, we call init_cpu_to_node() and
init_gi_nodes(), which initialize any memoryless node we might have that
have either CPU or Initiator affinity, meaning we allocate pg_data_t
struct for them and we mark them as ONLINE.
So far so good, but the thing is that after ("mm: handle uninitialized
numa nodes gracefully"), we allocate all possible NUMA nodes in
free_area_init(), meaning we have a picture like the following:
setup_arch
x86_numa_init
numa_init
numa_register_memblks <-- allocate non-memoryless node
x86_init.paging.pagetable_init
...
free_area_init
free_area_init_memoryless <-- allocate memoryless node
init_cpu_to_node
alloc_node_data <-- allocate memoryless node with CPU
free_area_init_memoryless_node
init_gi_nodes
alloc_node_data <-- allocate memoryless node with Initiator
free_area_init_memoryless_node
free_area_init() already allocates all possible NUMA nodes, but
init_cpu_to_node() and init_gi_nodes() are clueless about that, so they
go ahead and allocate a new pg_data_t struct without checking anything,
meaning we end up allocating twice.
It should be mad clear that this only happens in the case where
memoryless NUMA node happens to have a CPU/Initiator affinity.
So get rid of init_memory_less_node() and just set the node online.
Note that setting the node online is needed, otherwise we choke down the
chain when bringup_nonboot_cpus() ends up calling
__try_online_node()->register_one_node()->... and we blow up in
bus_add_device(). As can be seen here:
BUG: kernel NULL pointer dereference, address: 0000000000000060
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.17.0-rc4-1-default+ #45
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.0.0-prebuilt.qemu-project.org 04/4
RIP: 0010:bus_add_device+0x5a/0x140
Code: 8b 74 24 20 48 89 df e8 84 96 ff ff 85 c0 89 c5 75 38 48 8b 53 50 48 85 d2 0f 84 bb 00 004
RSP: 0000:ffffc9000022bd10 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff888100987400 RCX: ffff8881003e4e19
RDX: ffff8881009a5e00 RSI: ffff888100987400 RDI: ffff888100987400
RBP: 0000000000000000 R08: ffff8881003e4e18 R09: ffff8881003e4c98
R10: 0000000000000000 R11: ffff888100402bc0 R12: ffffffff822ceba0
R13: 0000000000000000 R14: ffff888100987400 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88853fc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000060 CR3: 000000000200a001 CR4: 00000000001706b0
Call Trace:
device_add+0x4c0/0x910
__register_one_node+0x97/0x2d0
__try_online_node+0x85/0xc0
try_online_node+0x25/0x40
cpu_up+0x4f/0x100
bringup_nonboot_cpus+0x4f/0x60
smp_init+0x26/0x79
kernel_init_freeable+0x130/0x2f1
kernel_init+0x17/0x150
ret_from_fork+0x22/0x30
The reason is simple, by the time bringup_nonboot_cpus() gets called, we
did not register the node_subsys bus yet, so we crash when
bus_add_device() tries to dereference bus()->p.
The following shows the order of the calls:
kernel_init_freeable
smp_init
bringup_nonboot_cpus
...
bus_add_device() <- we did not register node_subsys yet
do_basic_setup
do_initcalls
postcore_initcall(register_node_type);
register_node_type
subsys_system_register
subsys_register
bus_register <- register node_subsys bus
Why setting the node online saves us then? Well, simply because
__try_online_node() backs off when the node is online, meaning we do not
end up calling register_one_node() in the first place.
This is subtle, broken and deserves a deep analysis and thought about
how to put this into shape, but for now let us have this easy fix for
the leaking memory issue.
[osalvador@suse.de: add comments]
Link: https://lkml.kernel.org/r/20220221142649.3457-1-osalvador@suse.de
Link: https://lkml.kernel.org/r/20220218224302.5282-2-osalvador@suse.de
Fixes: da4490c958ad ("mm: handle uninitialized numa nodes gracefully")
Signed-off-by: Oscar Salvador <osalvador@suse.de>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Rafael Aquini <raquini@redhat.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Alexey Makhalov <amakhalov@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Mel Gorman
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2a791f4412 |
mm/page_alloc: do not prefetch buddies during bulk free
free_pcppages_bulk() has taken two passes through the pcp lists since
commit
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Mel Gorman
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f26b3fa046 |
mm/page_alloc: limit number of high-order pages on PCP during bulk free
When a PCP is mostly used for frees then high-order pages can exist on
PCP lists for some time. This is problematic when the allocation
pattern is all allocations from one CPU and all frees from another
resulting in colder pages being used. When bulk freeing pages, limit
the number of high-order pages that are stored on the PCP lists.
Netperf running on localhost exhibits this pattern and while it does not
matter for some machines, it does matter for others with smaller caches
where cache misses cause problems due to reduced page reuse. Pages
freed directly to the buddy list may be reused quickly while still cache
hot where as storing on the PCP lists may be cold by the time
free_pcppages_bulk() is called.
Using perf kmem:mm_page_alloc, the 5 most used page frames were
5.17-rc3
13041 pfn=0x111a30
13081 pfn=0x5814d0
13097 pfn=0x108258
13121 pfn=0x689598
13128 pfn=0x5814d8
5.17-revert-highpcp
192009 pfn=0x54c140
195426 pfn=0x1081d0
200908 pfn=0x61c808
243515 pfn=0xa9dc20
402523 pfn=0x222bb8
5.17-full-series
142693 pfn=0x346208
162227 pfn=0x13bf08
166413 pfn=0x2711e0
166950 pfn=0x2702f8
The spread is wider as there is still time before pages freed to one PCP
get released with a tradeoff between fast reuse and reduced zone lock
acquisition.
On the machine used to gather the traces, the headline performance was
equivalent.
netperf-tcp
5.17.0-rc3 5.17.0-rc3 5.17.0-rc3
vanilla mm-reverthighpcp-v1r1 mm-highpcplimit-v2
Hmean 64 839.93 ( 0.00%) 840.77 ( 0.10%) 841.02 ( 0.13%)
Hmean 128 1614.22 ( 0.00%) 1622.07 * 0.49%* 1636.41 * 1.37%*
Hmean 256 2952.00 ( 0.00%) 2953.19 ( 0.04%) 2977.76 * 0.87%*
Hmean 1024 10291.67 ( 0.00%) 10239.17 ( -0.51%) 10434.41 * 1.39%*
Hmean 2048 17335.08 ( 0.00%) 17399.97 ( 0.37%) 17134.81 * -1.16%*
Hmean 3312 22628.15 ( 0.00%) 22471.97 ( -0.69%) 22422.78 ( -0.91%)
Hmean 4096 25009.50 ( 0.00%) 24752.83 * -1.03%* 24740.41 ( -1.08%)
Hmean 8192 32745.01 ( 0.00%) 31682.63 * -3.24%* 32153.50 * -1.81%*
Hmean 16384 39759.59 ( 0.00%) 36805.78 * -7.43%* 38948.13 * -2.04%*
On a 1-socket skylake machine with a small CPU cache that suffers more if
cache misses are too high
netperf-tcp
5.17.0-rc3 5.17.0-rc3 5.17.0-rc3
vanilla mm-reverthighpcp-v1 mm-highpcplimit-v2
Hmean 64 938.95 ( 0.00%) 941.50 * 0.27%* 943.61 * 0.50%*
Hmean 128 1843.10 ( 0.00%) 1857.58 * 0.79%* 1861.09 * 0.98%*
Hmean 256 3573.07 ( 0.00%) 3667.45 * 2.64%* 3674.91 * 2.85%*
Hmean 1024 13206.52 ( 0.00%) 13487.80 * 2.13%* 13393.21 * 1.41%*
Hmean 2048 22870.23 ( 0.00%) 23337.96 * 2.05%* 23188.41 * 1.39%*
Hmean 3312 31001.99 ( 0.00%) 32206.50 * 3.89%* 31863.62 * 2.78%*
Hmean 4096 35364.59 ( 0.00%) 36490.96 * 3.19%* 36112.54 * 2.11%*
Hmean 8192 48497.71 ( 0.00%) 49954.05 * 3.00%* 49588.26 * 2.25%*
Hmean 16384 58410.86 ( 0.00%) 60839.80 * 4.16%* 62282.96 * 6.63%*
Note that this was a machine that did not benefit from caching high-order
pages and performance is almost restored with the series applied. It's
not fully restored as cache misses are still higher. This is a trade-off
between optimising for a workload that does all allocs on one CPU and
frees on another or more general workloads that need high-order pages for
SLUB and benefit from avoiding zone->lock for every SLUB refill/drain.
Link: https://lkml.kernel.org/r/20220217002227.5739-7-mgorman@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Tested-by: Aaron Lu <aaron.lu@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
||
|
Mel Gorman
|
8b10b465d0 |
mm/page_alloc: free pages in a single pass during bulk free
free_pcppages_bulk() has taken two passes through the pcp lists since
commit
|
||
|
Mel Gorman
|
d61372bc41 |
mm/page_alloc: drain the requested list first during bulk free
Prior to the series, pindex 0 (order-0 MIGRATE_UNMOVABLE) was always skipped first and the precise reason is forgotten. A potential reason may have been to artificially preserve MIGRATE_UNMOVABLE but there is no reason why that would be optimal as it depends on the workload. The more likely reason is that it was less complicated to do a pre-increment instead of a post-increment in terms of overall code flow. As free_pcppages_bulk() now typically receives the pindex of the PCP list that exceeded high, always start draining that list. Link: https://lkml.kernel.org/r/20220217002227.5739-5-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Aaron Lu <aaron.lu@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
fd56eef258 |
mm/page_alloc: simplify how many pages are selected per pcp list during bulk free
free_pcppages_bulk() selects pages to free by round-robining between lists. Originally this was to evenly shrink pages by migratetype but uneven freeing is inevitable due to high pages. Simplify list selection by starting with a list that definitely has pages on it in free_unref_page_commit() and for drain, it does not matter where draining starts as all pages are removed. Link: https://lkml.kernel.org/r/20220217002227.5739-4-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Aaron Lu <aaron.lu@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
35b6d770e6 |
mm/page_alloc: track range of active PCP lists during bulk free
free_pcppages_bulk() frees pages in a round-robin fashion. Originally, this was dealing only with migratetypes but storing high-order pages means that there can be many more empty lists that are uselessly checked. Track the minimum and maximum active pindex to reduce the search space. Link: https://lkml.kernel.org/r/20220217002227.5739-3-mgorman@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Tested-by: Aaron Lu <aaron.lu@intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
Mel Gorman
|
ca7b59b1de |
mm/page_alloc: fetch the correct pcp buddy during bulk free
Patch series "Follow-up on high-order PCP caching", v2. Commit |
||
Alistair Popple
|
ddbc84f3f5 |
mm/pages_alloc.c: don't create ZONE_MOVABLE beyond the end of a node
ZONE_MOVABLE uses the remaining memory in each node. Its starting pfn
is also aligned to MAX_ORDER_NR_PAGES. It is possible for the remaining
memory in a node to be less than MAX_ORDER_NR_PAGES, meaning there is
not enough room for ZONE_MOVABLE on that node.
Unfortunately this condition is not checked for. This leads to
zone_movable_pfn[] getting set to a pfn greater than the last pfn in a
node.
calculate_node_totalpages() then sets zone->present_pages to be greater
than zone->spanned_pages which is invalid, as spanned_pages represents
the maximum number of pages in a zone assuming no holes.
Subsequently it is possible free_area_init_core() will observe a zone of
size zero with present pages. In this case it will skip setting up the
zone, including the initialisation of free_lists[].
However populated_zone() checks zone->present_pages to see if a zone has
memory available. This is used by iterators such as
walk_zones_in_node(). pagetypeinfo_showfree() uses this to walk the
free_list of each zone in each node, which are assumed to be initialised
due to the zone not being empty.
As free_area_init_core() never initialised the free_lists[] this results
in the following kernel crash when trying to read /proc/pagetypeinfo:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC NOPTI
CPU: 0 PID: 456 Comm: cat Not tainted 5.16.0 #461
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
RIP: 0010:pagetypeinfo_show+0x163/0x460
Code: 9e 82 e8 80 57 0e 00 49 8b 06 b9 01 00 00 00 4c 39 f0 75 16 e9 65 02 00 00 48 83 c1 01 48 81 f9 a0 86 01 00 0f 84 48 02 00 00 <48> 8b 00 4c 39 f0 75 e7 48 c7 c2 80 a2 e2 82 48 c7 c6 79 ef e3 82
RSP: 0018:ffffc90001c4bd10 EFLAGS: 00010003
RAX: 0000000000000000 RBX: ffff88801105f638 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 000000000000068b RDI: ffff8880163dc68b
RBP: ffffc90001c4bd90 R08: 0000000000000001 R09: ffff8880163dc67e
R10: 656c6261766f6d6e R11: 6c6261766f6d6e55 R12: ffff88807ffb4a00
R13: ffff88807ffb49f8 R14: ffff88807ffb4580 R15: ffff88807ffb3000
FS: 00007f9c83eff5c0(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000013c8e000 CR4: 0000000000350ef0
Call Trace:
seq_read_iter+0x128/0x460
proc_reg_read_iter+0x51/0x80
new_sync_read+0x113/0x1a0
vfs_read+0x136/0x1d0
ksys_read+0x70/0xf0
__x64_sys_read+0x1a/0x20
do_syscall_64+0x3b/0xc0
entry_SYSCALL_64_after_hwframe+0x44/0xae
Fix this by checking that the aligned zone_movable_pfn[] does not exceed
the end of the node, and if it does skip creating a movable zone on this
node.
Link: https://lkml.kernel.org/r/20220215025831.2113067-1-apopple@nvidia.com
Fixes:
|
||
Nathan Chancellor
|
a4812d47de |
mm/page_alloc: mark pagesets as __maybe_unused
Commit
|
||
David Hildenbrand
|
b3d40a2b6d |
mm: enforce pageblock_order < MAX_ORDER
Some places in the kernel don't really expect pageblock_order >= MAX_ORDER, and it looks like this is only possible in corner cases: 1) CONFIG_DEFERRED_STRUCT_PAGE_INIT we'll end up freeing pageblock_order pages via __free_pages_core(), which cannot possibly work. 2) find_zone_movable_pfns_for_nodes() will roundup the ZONE_MOVABLE start PFN to MAX_ORDER_NR_PAGES. Consequently with a bigger pageblock_order, we could have a single pageblock partially managed by two zones. 3) compaction code runs into __fragmentation_index() with order >= MAX_ORDER, when checking WARN_ON_ONCE(order >= MAX_ORDER). [1] 4) mm/page_reporting.c won't be reporting any pages with default page_reporting_order == pageblock_order, as we'll be skipping the reporting loop inside page_reporting_process_zone(). 5) __rmqueue_fallback() will never be able to steal with ALLOC_NOFRAGMENT. pageblock_order >= MAX_ORDER is weird either way: it's a pure optimization for making alloc_contig_range(), as used for allcoation of gigantic pages, a little more reliable to succeed. However, if there is demand for somewhat reliable allocation of gigantic pages, affected setups should be using CMA or boottime allocations instead. So let's make sure that pageblock_order < MAX_ORDER and simplify. [1] https://lkml.kernel.org/r/87r189a2ks.fsf@linux.ibm.com Link: https://lkml.kernel.org/r/20220214174132.219303-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Frank Rowand <frowand.list@gmail.com> Cc: John Garry via iommu <iommu@lists.linux-foundation.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Rob Herring <robh+dt@kernel.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
||
|
David Hildenbrand
|
e16faf2678 |
cma: factor out minimum alignment requirement
Patch series "mm: enforce pageblock_order < MAX_ORDER". Having pageblock_order >= MAX_ORDER seems to be able to happen in corner cases and some parts of the kernel are not prepared for it. For example, Aneesh has shown [1] that such kernels can be compiled on ppc64 with 64k base pages by setting FORCE_MAX_ZONEORDER=8, which will run into a WARN_ON_ONCE(order >= MAX_ORDER) in comapction code right during boot. We can get pageblock_order >= MAX_ORDER when the default hugetlb size is bigger than the maximum allocation granularity of the buddy, in which case we are no longer talking about huge pages but instead gigantic pages. Having pageblock_order >= MAX_ORDER can only make alloc_contig_range() of such gigantic pages more likely to succeed. Reliable use of gigantic pages either requires boot time allcoation or CMA, no need to overcomplicate some places in the kernel to optimize for corner cases that are broken in other areas of the kernel. This patch (of 2): Let's enforce pageblock_order < MAX_ORDER and simplify. Especially patch #1 can be regarded a cleanup before: [PATCH v5 0/6] Use pageblock_order for cma and alloc_contig_range alignment. [2] [1] https://lkml.kernel.org/r/87r189a2ks.fsf@linux.ibm.com [2] https://lkml.kernel.org/r/20220211164135.1803616-1-zi.yan@sent.com Link: https://lkml.kernel.org/r/20220214174132.219303-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Acked-by: Rob Herring <robh@kernel.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: John Garry via iommu <iommu@lists.linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |