Star64_linux/kernel
Paul E. McKenney b626c1b689 rcu: Provide OOM handler to motivate lazy RCU callbacks
In kernels built with CONFIG_RCU_FAST_NO_HZ=y, CPUs can accumulate a
large number of lazy callbacks, which as the name implies will be slow
to be invoked.  This can be a problem on small-memory systems, where the
default 6-second sleep for CPUs having only lazy RCU callbacks could well
be fatal.  This commit therefore installs an OOM hander that ensures that
every CPU with lazy callbacks has at least one non-lazy callback, in turn
ensuring timely advancement for these callbacks.

Updated to fix bug that disabled OOM killing, noted by Lai Jiangshan.

Updated to push the for_each_rcu_flavor() loop into rcu_oom_notify_cpu(),
thus reducing the number of IPIs, as suggested by Steven Rostedt.  Also
to make the for_each_online_cpu() loop be preemptible.  (Later, it might
be good to use smp_call_function(), as suggested by Peter Zijlstra.)

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Sasha Levin <levinsasha928@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2012-09-23 07:41:53 -07:00
..
debug kernel/debug: Make use of KGDB_REASON_NMI 2012-07-31 08:16:43 -05:00
events perf/trace: Add ability to set a target task for events 2012-07-31 17:02:05 +02:00
gcov
irq Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-08-03 10:56:44 -07:00
power Revert "NMI watchdog: fix for lockup detector breakage on resume" 2012-08-08 20:49:45 +02:00
sched Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-08-20 10:35:05 -07:00
time time: Move ktime_t overflow checking into timespec_valid_strict 2012-09-01 10:24:48 -07:00
trace tracing/syscalls: Fix perf syscall tracing when syscall_nr == -1 2012-08-17 15:19:46 -04:00
.gitignore
acct.c
async.c
audit.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
audit.h
audit_tree.c audit: clean up refcounting in audit-tree 2012-08-15 12:55:22 +02:00
audit_watch.c
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
cgroup.c Merge branch 'for-3.6' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2012-07-24 17:47:44 -07:00
cgroup_freezer.c
compat.c
configs.c
cpu.c mm/hotplug: correctly setup fallback zonelists when creating new pgdat 2012-07-31 18:42:44 -07:00
cpu_pm.c
cpuset.c
crash_dump.c
cred.c
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c posix_types.h: Cleanup stale __NFDBITS and related definitions 2012-07-26 13:36:43 -07:00
extable.c
fork.c uprobes: Fix mmap_region()'s mm->mm_rb corruption if uprobe_mmap() fails 2012-08-21 11:48:12 +02:00
freezer.c
futex.c
futex_compat.c
groups.c
hrtimer.c
hung_task.c
irq_work.c
itimer.c
jump_label.c
kallsyms.c
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c kdump: append newline to the last lien of vmcoreinfo note 2012-07-30 17:25:20 -07:00
kfifo.c
kmod.c kmod: avoid deadlock from recursive kmod call 2012-07-30 17:25:20 -07:00
kprobes.c
ksysfs.c
kthread.c
latencytop.c
lglock.c
lockdep.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
Makefile
module.c
mutex-debug.c
mutex-debug.h
mutex.c
mutex.h
notifier.c
nsproxy.c
padata.c
panic.c panic: fix a possible deadlock in panic() 2012-07-30 17:25:13 -07:00
params.c
pid.c
pid_namespace.c
posix-cpu-timers.c
posix-timers.c
printk.c printk: Fix calculation of length used to discard records 2012-08-12 21:25:50 +03:00
profile.c
ptrace.c
range.c
rcu.h
rcupdate.c
rcutiny.c
rcutiny_plugin.h
rcutorture.c
rcutree.c rcu: Prevent offline CPUs from executing RCU core code 2012-09-23 07:41:53 -07:00
rcutree.h rcu: Provide OOM handler to motivate lazy RCU callbacks 2012-09-23 07:41:53 -07:00
rcutree_plugin.h rcu: Provide OOM handler to motivate lazy RCU callbacks 2012-09-23 07:41:53 -07:00
rcutree_trace.c
relay.c
res_counter.c
resource.c resource: make sure requested range is included in the root range 2012-07-30 17:25:21 -07:00
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rtmutex_common.h
rwsem.c
seccomp.c
semaphore.c
signal.c
smp.c
smpboot.c
smpboot.h
softirq.c mm: allow PF_MEMALLOC from softirq context 2012-07-31 18:42:45 -07:00
spinlock.c
srcu.c
stacktrace.c
stop_machine.c
sys.c kernel/sys.c: avoid argv_free(NULL) 2012-07-30 17:25:13 -07:00
sys_ni.c
sysctl.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-08-01 10:26:23 -07:00
sysctl_binary.c mm: prepare for removal of obsolete /proc/sys/vm/nr_pdflush_threads 2012-07-31 18:42:40 -07:00
task_work.c task_work: add a scheduling point in task_work_run() 2012-08-21 09:11:44 -07:00
taskstats.c taskstats: check nla_reserve() return 2012-07-30 17:25:21 -07:00
test_kprobes.c
time.c
timeconst.pl
timer.c alpha: take a bunch of syscalls into osf_sys.c 2012-08-19 08:41:19 -07:00
tracepoint.c
tsacct.c
uid16.c
up.c
user-return-notifier.c
user.c
user_namespace.c
utsname.c
utsname_sysctl.c
wait.c
watchdog.c Revert "NMI watchdog: fix for lockup detector breakage on resume" 2012-08-08 20:49:45 +02:00
workqueue.c
workqueue_sched.h