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Filename Latest commit message Latest commit date
Paul E. McKenney 87834546ea mm/mmap.c: Add cond_resched() for exit_mmap() CPU stalls
[ Upstream commit 0a3b3c253a1eb2c7fe7f34086d46660c909abeb3 ]

A large process running on a heavily loaded system can encounter the
following RCU CPU stall warning:

  rcu: INFO: rcu_sched self-detected stall on CPU
  rcu: 	3-....: (20998 ticks this GP) idle=4ea/1/0x4000000000000002 softirq=556558/556558 fqs=5190
  	(t=21013 jiffies g=1005461 q=132576)
  NMI backtrace for cpu 3
  CPU: 3 PID: 501900 Comm: aio-free-ring-w Kdump: loaded Not tainted 5.2.9-108_fbk12_rc3_3858_gb83b75af7909 #1
  Hardware name: Wiwynn   HoneyBadger/PantherPlus, BIOS HBM6.71 02/03/2016
  Call Trace:
   <IRQ>
   dump_stack+0x46/0x60
   nmi_cpu_backtrace.cold.3+0x13/0x50
   ? lapic_can_unplug_cpu.cold.27+0x34/0x34
   nmi_trigger_cpumask_backtrace+0xba/0xca
   rcu_dump_cpu_stacks+0x99/0xc7
   rcu_sched_clock_irq.cold.87+0x1aa/0x397
   ? tick_sched_do_timer+0x60/0x60
   update_process_times+0x28/0x60
   tick_sched_timer+0x37/0x70
   __hrtimer_run_queues+0xfe/0x270
   hrtimer_interrupt+0xf4/0x210
   smp_apic_timer_interrupt+0x5e/0x120
   apic_timer_interrupt+0xf/0x20
   </IRQ>
  RIP: 0010:kmem_cache_free+0x223/0x300
  Code: 88 00 00 00 0f 85 ca 00 00 00 41 8b 55 18 31 f6 f7 da 41 f6 45 0a 02 40 0f 94 c6 83 c6 05 9c 41 5e fa e8 a0 a7 01 00 41 56 9d <49> 8b 47 08 a8 03 0f 85 87 00 00 00 65 48 ff 08 e9 3d fe ff ff 65
  RSP: 0018:ffffc9000e8e3da8 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
  RAX: 0000000000020000 RBX: ffff88861b9de960 RCX: 0000000000000030
  RDX: fffffffffffe41e8 RSI: 000060777fe3a100 RDI: 000000000001be18
  RBP: ffffea00186e7780 R08: ffffffffffffffff R09: ffffffffffffffff
  R10: ffff88861b9dea28 R11: ffff88887ffde000 R12: ffffffff81230a1f
  R13: ffff888854684dc0 R14: 0000000000000206 R15: ffff8888547dbc00
   ? remove_vma+0x4f/0x60
   remove_vma+0x4f/0x60
   exit_mmap+0xd6/0x160
   mmput+0x4a/0x110
   do_exit+0x278/0xae0
   ? syscall_trace_enter+0x1d3/0x2b0
   ? handle_mm_fault+0xaa/0x1c0
   do_group_exit+0x3a/0xa0
   __x64_sys_exit_group+0x14/0x20
   do_syscall_64+0x42/0x100
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

And on a PREEMPT=n kernel, the "while (vma)" loop in exit_mmap() can run
for a very long time given a large process.  This commit therefore adds
a cond_resched() to this loop, providing RCU any needed quiescent states.

Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <linux-mm@kvack.org>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2020-08-19 08:16:02 +02:00
arch arm64: dts: hisilicon: hikey: fixes to comply with adi, adv7533 DT binding 2020-08-19 08:16:01 +02:00
block iocost: Fix check condition of iocg abs_vdebt 2020-08-19 08:15:58 +02:00
certs
crypto keys: asymmetric: fix error return code in software_key_query() 2020-07-22 09:33:04 +02:00
Documentation doc: dt: bindings: usb: dwc3: Update entries for disabling SS instances in park mode 2020-07-22 09:32:59 +02:00
drivers irqchip/irq-mtk-sysirq: Replace spinlock with raw_spinlock 2020-08-19 08:16:02 +02:00
fs btrfs: fix lockdep splat from btrfs_dump_space_info 2020-08-19 08:16:01 +02:00
include seccomp: Fix ioctl number for SECCOMP_IOCTL_NOTIF_ID_VALID 2020-08-19 08:15:58 +02:00
init x86: Fix early boot crash on gcc-10, third try 2020-05-20 08:20:34 +02:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-20 08:20:16 +02:00
kernel seccomp: Fix ioctl number for SECCOMP_IOCTL_NOTIF_ID_VALID 2020-08-19 08:15:58 +02:00
lib crc-t10dif: Fix potential crypto notify dead-lock 2020-08-19 08:15:54 +02:00
LICENSES
mm mm/mmap.c: Add cond_resched() for exit_mmap() CPU stalls 2020-08-19 08:16:02 +02:00
net Bluetooth: add a mutex lock to avoid UAF in do_enale_set 2020-08-19 08:15:59 +02:00
samples samples/vfs: avoid warning in statx override 2020-07-09 09:37:54 +02:00
scripts recordmcount: only record relocation of type R_AARCH64_CALL26 on arm64. 2020-08-19 08:15:57 +02:00
security ima: move APPRAISE_BOOTPARAM dependency on ARCH_POLICY to runtime 2020-08-11 15:33:41 +02:00
sound ALSA: hda: fix NULL pointer dereference during suspend 2020-08-11 15:33:37 +02:00
tools seccomp: Fix ioctl number for SECCOMP_IOCTL_NOTIF_ID_VALID 2020-08-19 08:15:58 +02:00
usr
virt KVM: arm64: Don't inherit exec permission across page-table levels 2020-08-05 09:59:51 +02:00
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Makefile Linux 5.4.58 2020-08-11 15:33:42 +02:00
README

Linux kernel
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There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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    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.