linux

mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ synced 2026-10-09 18:15:49 +00:00

No description

C 96.9%
Assembly 0.9%
Rust 0.6%
Shell 0.6%
Python 0.5%
Other 0.3%

Find a file

Pingfan Liu 2c4d26dad7 srcu: Delegate work to the boot cpu if using SRCU_SIZE_SMALL [ Upstream commit `7f24626d6d` ] Commit `994f706872` ("srcu: Make Tree SRCU able to operate without snp_node array") assumes that cpu 0 is always online. However, there really are situations when some other CPU is the boot CPU, for example, when booting a kdump kernel with the maxcpus=1 boot parameter. On PowerPC, the kdump kernel can hang as follows: ... [ 1.740036] systemd[1]: Hostname set to <xyz.com> [ 243.686240] INFO: task systemd:1 blocked for more than 122 seconds. [ 243.686264] Not tainted 6.1.0-rc1 #1 [ 243.686272] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 243.686281] task:systemd state:D stack:0 pid:1 ppid:0 flags:0x00042000 [ 243.686296] Call Trace: [ 243.686301] [c000000016657640] [c000000016657670] 0xc000000016657670 (unreliable) [ 243.686317] [c000000016657830] [c00000001001dec0] __switch_to+0x130/0x220 [ 243.686333] [c000000016657890] [c000000010f607b8] __schedule+0x1f8/0x580 [ 243.686347] [c000000016657940] [c000000010f60bb4] schedule+0x74/0x140 [ 243.686361] [c0000000166579b0] [c000000010f699b8] schedule_timeout+0x168/0x1c0 [ 243.686374] [c000000016657a80] [c000000010f61de8] __wait_for_common+0x148/0x360 [ 243.686387] [c000000016657b20] [c000000010176bb0] __flush_work.isra.0+0x1c0/0x3d0 [ 243.686401] [c000000016657bb0] [c0000000105f2768] fsnotify_wait_marks_destroyed+0x28/0x40 [ 243.686415] [c000000016657bd0] [c0000000105f21b8] fsnotify_destroy_group+0x68/0x160 [ 243.686428] [c000000016657c40] [c0000000105f6500] inotify_release+0x30/0xa0 [ 243.686440] [c000000016657cb0] [c0000000105751a8] __fput+0xc8/0x350 [ 243.686452] [c000000016657d00] [c00000001017d524] task_work_run+0xe4/0x170 [ 243.686464] [c000000016657d50] [c000000010020e94] do_notify_resume+0x134/0x140 [ 243.686478] [c000000016657d80] [c00000001002eb18] interrupt_exit_user_prepare_main+0x198/0x270 [ 243.686493] [c000000016657de0] [c00000001002ec60] syscall_exit_prepare+0x70/0x180 [ 243.686505] [c000000016657e10] [c00000001000bf7c] system_call_vectored_common+0xfc/0x280 [ 243.686520] --- interrupt: 3000 at 0x7fffa47d5ba4 [ 243.686528] NIP: 00007fffa47d5ba4 LR: 0000000000000000 CTR: 0000000000000000 [ 243.686538] REGS: c000000016657e80 TRAP: 3000 Not tainted (6.1.0-rc1) [ 243.686548] MSR: 800000000000d033 <SF,EE,PR,ME,IR,DR,RI,LE> CR: 42044440 XER: 00000000 [ 243.686572] IRQMASK: 0 [ 243.686572] GPR00: 0000000000000006 00007ffffa606710 00007fffa48e7200 0000000000000000 [ 243.686572] GPR04: 0000000000000002 000000000000000a 0000000000000000 0000000000000001 [ 243.686572] GPR08: 000001000c172dd0 0000000000000000 0000000000000000 0000000000000000 [ 243.686572] GPR12: 0000000000000000 00007fffa4ff4bc0 0000000000000000 0000000000000000 [ 243.686572] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 243.686572] GPR20: 0000000132dfdc50 000000000000000e 0000000000189375 0000000000000000 [ 243.686572] GPR24: 00007ffffa606ae0 0000000000000005 000001000c185490 000001000c172570 [ 243.686572] GPR28: 000001000c172990 000001000c184850 000001000c172e00 00007fffa4fedd98 [ 243.686683] NIP [00007fffa47d5ba4] 0x7fffa47d5ba4 [ 243.686691] LR [0000000000000000] 0x0 [ 243.686698] --- interrupt: 3000 [ 243.686708] INFO: task kworker/u16:1:24 blocked for more than 122 seconds. [ 243.686717] Not tainted 6.1.0-rc1 #1 [ 243.686724] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 243.686733] task:kworker/u16:1 state:D stack:0 pid:24 ppid:2 flags:0x00000800 [ 243.686747] Workqueue: events_unbound fsnotify_mark_destroy_workfn [ 243.686758] Call Trace: [ 243.686762] [c0000000166736e0] [c00000004fd91000] 0xc00000004fd91000 (unreliable) [ 243.686775] [c0000000166738d0] [c00000001001dec0] __switch_to+0x130/0x220 [ 243.686788] [c000000016673930] [c000000010f607b8] __schedule+0x1f8/0x580 [ 243.686801] [c0000000166739e0] [c000000010f60bb4] schedule+0x74/0x140 [ 243.686814] [c000000016673a50] [c000000010f699b8] schedule_timeout+0x168/0x1c0 [ 243.686827] [c000000016673b20] [c000000010f61de8] __wait_for_common+0x148/0x360 [ 243.686840] [c000000016673bc0] [c000000010210840] __synchronize_srcu.part.0+0xa0/0xe0 [ 243.686855] [c000000016673c30] [c0000000105f2c64] fsnotify_mark_destroy_workfn+0xc4/0x1a0 [ 243.686868] [c000000016673ca0] [c000000010174ea8] process_one_work+0x2a8/0x570 [ 243.686882] [c000000016673d40] [c000000010175208] worker_thread+0x98/0x5e0 [ 243.686895] [c000000016673dc0] [c0000000101828d4] kthread+0x124/0x130 [ 243.686908] [c000000016673e10] [c00000001000cd40] ret_from_kernel_thread+0x5c/0x64 [ 366.566274] INFO: task systemd:1 blocked for more than 245 seconds. [ 366.566298] Not tainted 6.1.0-rc1 #1 [ 366.566305] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 366.566314] task:systemd state:D stack:0 pid:1 ppid:0 flags:0x00042000 [ 366.566329] Call Trace: ... The above splat occurs because PowerPC really does use maxcpus=1 instead of nr_cpus=1 in the kernel command line. Consequently, the (quite possibly non-zero) kdump CPU is the only online CPU in the kdump kernel. SRCU unconditionally queues a sdp->work on cpu 0, for which no worker thread has been created, so sdp->work will be never executed and __synchronize_srcu() will never be completed. This commit therefore replaces CPU ID 0 with get_boot_cpu_id() in key places in Tree SRCU. Since the CPU indicated by get_boot_cpu_id() is guaranteed to be online, this avoids the above splat. Signed-off-by: Pingfan Liu <kernelfans@gmail.com> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Lai Jiangshan <jiangshanlai@gmail.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> To: rcu@vger.kernel.org Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>		History 2023-03-10 09:33:48 +01:00
arch	perf/x86/intel/uncore: Add Meteor Lake support	2023-03-10 09:33:47 +01:00
block	blk-cgroup: synchronize pd_free_fn() from blkg_free_workfn() and blkcg_deactivate_policy()	2023-03-10 09:33:46 +01:00
certs	certs: Fix build error when PKCS#11 URI contains semicolon	2023-02-09 11:28:11 +01:00
crypto	crypto: rsa-pkcs1pad - Use akcipher_request_complete	2023-03-10 09:33:03 +01:00
Documentation	ASoC: dt-bindings: meson: fix gx-card codec node regex	2023-03-10 09:33:19 +01:00
drivers	wifi: brcmfmac: Fix potential stack-out-of-bounds in brcmf_c_preinit_dcmds()	2023-03-10 09:33:48 +01:00
fs	btrfs: scrub: improve tree block error reporting	2023-03-10 09:33:46 +01:00
include	rcu: Make RCU_LOCKDEP_WARN() avoid early lockdep checks	2023-03-10 09:33:48 +01:00
init	gcc: disable -Warray-bounds for gcc-11 too	2023-01-14 10:33:43 +01:00
io_uring	use less confusing names for iov_iter direction initializers	2023-02-09 11:28:04 +01:00
ipc	ipc: fix memory leak in init_mqueue_fs()	2022-12-31 13:32:01 +01:00
kernel	srcu: Delegate work to the boot cpu if using SRCU_SIZE_SMALL	2023-03-10 09:33:48 +01:00
lib	cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG	2023-03-10 09:33:47 +01:00
LICENSES	LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers	2021-12-16 14:33:10 +01:00
mm	mm/gup: add folio to list when folio_isolate_lru() succeed	2023-02-22 12:59:54 +01:00
net	NFS: fix disabling of swap	2023-03-10 09:33:22 +01:00
rust	rust: print: avoid evaluating arguments in `pr_*` macros in `unsafe` blocks	2023-02-06 08:06:34 +01:00
samples	ftrace: Export ftrace_free_filter() to modules	2023-02-01 08:34:37 +01:00
scripts	builddeb: clean generated package content	2023-03-10 09:33:41 +01:00
security	randstruct: disable Clang 15 support	2023-02-25 11:25:43 +01:00
sound	ALSA: hda/hdmi: Register with vga_switcheroo on Dual GPU Macbooks	2023-03-10 09:33:23 +01:00
tools	objtool: add UACCESS exceptions for __tsan_volatile_read/write	2023-03-10 09:33:28 +01:00
usr	usr/gen_init_cpio.c: remove unnecessary -1 values from int file	2022-10-03 14:21:44 -07:00
virt	kvm/vfio: Fix potential deadlock on vfio group_lock	2023-02-01 08:34:36 +01:00
.clang-format	inet: ping: use hlist_nulls rcu iterator during lookup	2022-12-01 12:42:46 +01:00
.cocciconfig	scripts: add Linux .cocciconfig for coccinelle	2016-07-22 12:13:39 +02:00
.get_maintainer.ignore	get_maintainer: add Alan to .get_maintainer.ignore	2022-08-20 15:17:44 -07:00
.gitattributes	.gitattributes: use 'dts' diff driver for dts files	2019-12-04 19:44:11 -08:00
.gitignore	Kbuild: add Rust support	2022-09-28 09:02:20 +02:00
.mailmap	9 hotfixes. 6 for MM, 3 for other areas. Four of these patches address	2022-12-10 17:10:52 -08:00
.rustfmt.toml	rust: add `.rustfmt.toml`	2022-09-28 09:02:20 +02:00
COPYING	COPYING: state that all contributions really are covered by this file	2020-02-10 13:32:20 -08:00
CREDITS	MAINTAINERS: Remove Michal Marek from Kbuild maintainers	2022-11-16 14:53:00 +09:00
Kbuild	Kbuild updates for v6.1	2022-10-10 12:00:45 -07:00
Kconfig	kbuild: ensure full rebuild when the compiler is updated	2020-05-12 13:28:33 +09:00
MAINTAINERS	audit: update the mailing list in MAINTAINERS	2023-02-25 11:25:42 +01:00
Makefile	Linux 6.1.15	2023-03-03 11:52:25 +01:00
README	Drop all 00-INDEX files from Documentation/	2018-09-09 15:08:58 -06:00

README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.