kernel_optimize_test/kernel
David Rientjes da39da3a54 mm, oom: remove task_lock protecting comm printing
The oom killer takes task_lock() in a couple of places solely to protect
printing the task's comm.

A process's comm, including current's comm, may change due to
/proc/pid/comm or PR_SET_NAME.

The comm will always be NULL-terminated, so the worst race scenario would
only be during update.  We can tolerate a comm being printed that is in
the middle of an update to avoid taking the lock.

Other locations in the kernel have already dropped task_lock() when
printing comm, so this is consistent.

Signed-off-by: David Rientjes <rientjes@google.com>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Vladimir Davydov <vdavydov@parallels.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-05 19:34:48 -08:00
..
bpf bpf, verifier: annotate verbose printer with __printf 2015-11-03 11:29:56 -05:00
configs
debug
events Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2015-11-04 09:41:05 -08:00
gcov
irq Power management and ACPI updates for v4.4-rc1 2015-11-04 18:10:13 -08:00
livepatch
locking Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 18:03:50 -08:00
power PM / hibernate: fix a comment typo 2015-10-14 02:37:17 +02:00
printk
rcu
sched Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 18:03:50 -08:00
time Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 14:13:41 -08:00
trace Merge branch 'for-4.4/core' of git://git.kernel.dk/linux-block 2015-11-04 20:28:10 -08:00
.gitignore
acct.c
async.c
audit_fsnotify.c
audit_tree.c
audit_watch.c
audit.c
audit.h
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
cgroup_freezer.c
cgroup_pids.c
cgroup.c
compat.c
configs.c
context_tracking.c
cpu_pm.c
cpu.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 18:03:50 -08:00
cpuset.c mm, oom: remove task_lock protecting comm printing 2015-11-05 19:34:48 -08:00
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-11-03 18:03:50 -08:00
extable.c
fork.c posix_cpu_timer: Convert cputimer->running to bool 2015-10-15 11:23:41 +02:00
freezer.c
futex_compat.c
futex.c driver core update for 4.4-rc1 2015-11-04 21:50:37 -08:00
groups.c
hung_task.c
irq_work.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec_core.c kexec/crash: Say which char is the unrecognized 2015-10-21 11:10:57 +02:00
kexec_file.c
kexec_internal.h
kexec.c
kmod.c kmod: don't run async usermode helper as a child of kworker thread 2015-10-23 17:55:10 +09:00
kprobes.c
ksysfs.c
kthread.c
latencytop.c
Makefile
membarrier.c
memremap.c memremap: fix highmem support 2015-10-26 16:55:56 -04:00
module_signing.c
module-internal.h
module.c
notifier.c
nsproxy.c
padata.c
panic.c
params.c
pid_namespace.c
pid.c
profile.c
ptrace.c seccomp, ptrace: add support for dumping seccomp filters 2015-10-27 19:55:13 -07:00
range.c
reboot.c
relay.c
resource.c
seccomp.c seccomp, ptrace: add support for dumping seccomp filters 2015-10-27 19:55:13 -07:00
signal.c
smp.c
smpboot.c stop_machine: Kill smp_hotplug_thread->pre_unpark, introduce stop_machine_unpark() 2015-10-20 10:23:55 +02:00
smpboot.h
softirq.c
stacktrace.c
stop_machine.c sched: Move cpu_active() tests from stop_two_cpus() into migrate_swap_stop() 2015-10-20 10:25:56 +02:00
sys_ni.c
sys.c
sysctl_binary.c
sysctl.c kernel/watchdog.c: add sysctl knob hardlockup_panic 2015-11-05 19:34:48 -08:00
task_work.c
taskstats.c
test_kprobes.c
torture.c
tracepoint.c
tsacct.c
uid16.c
up.c
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
watchdog.c kernel/watchdog.c: fix race between proc_watchdog_thresh() and watchdog_timer_fn() 2015-11-05 19:34:48 -08:00
workqueue_internal.h
workqueue.c