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Peter Zijlstra d72bce0e67 rcu: Cure load woes 
Commit cc3ce5176d (rcu: Start RCU kthreads in TASK_INTERRUPTIBLE
state) fudges a sleeping task' state, resulting in the scheduler seeing
a TASK_UNINTERRUPTIBLE task going to sleep, but a TASK_INTERRUPTIBLE
task waking up. The result is unbalanced load calculation.

The problem that patch tried to address is that the RCU threads could
stay in UNINTERRUPTIBLE state for quite a while and triggering the hung
task detector due to on-demand wake-ups.

Cure the problem differently by always giving the tasks at least one
wake-up once the CPU is fully up and running, this will kick them out of
the initial UNINTERRUPTIBLE state and into the regular INTERRUPTIBLE
wait state.

[ The alternative would be teaching kthread_create() to start threads as
  INTERRUPTIBLE but that needs a tad more thought. ]

Reported-by: Damien Wyart <damien.wyart@free.fr>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Paul E. McKenney <paul.mckenney@linaro.org>
Link: http://lkml.kernel.org/r/1306755291.1200.2872.camel@twins
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-05-31 10:01:48 +02:00
..
debug
events perf: Fix SIGIO handling 2011-05-28 17:04:59 +02:00
gcov
irq irq: Remove smp_affinity_list when unregister irq proc 2011-05-26 13:15:28 +02:00
power PM / Hibernate: Update kerneldoc comments in hibernate.c 2011-05-24 23:36:06 +02:00
time
trace ftrace: Add internal recursive checks 2011-05-25 22:13:49 -04:00
.gitignore
acct.c
async.c
audit_tree.c
audit_watch.c
audit.c
audit.h
auditfilter.c
auditsc.c
backtracetest.c
bounds.c
capability.c
cgroup_freezer.c cgroups: add per-thread subsystem callbacks 2011-05-26 17:12:34 -07:00
cgroup.c cgroup: remove the ns_cgroup 2011-05-26 17:12:34 -07:00
compat.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2011-05-25 15:35:32 -07:00
configs.c
cpu.c
cpuset.c cpuset: Fix cpuset_cpus_allowed_fallback(), don't update tsk->rt.nr_cpus_allowed 2011-05-28 17:02:57 +02:00
crash_dump.c
cred.c Merge branch 'docs-move' of git://git.kernel.org/pub/scm/linux/kernel/git/rdunlap/linux-docs 2011-05-27 10:25:02 -07:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c
extable.c
fork.c mm: Fix boot crash in mm_alloc() 2011-05-29 11:32:28 -07:00
freezer.c
futex_compat.c
futex.c
groups.c
hrtimer.c hrtimers: Fix typo causing erratic timers 2011-05-25 15:31:58 -07:00
hung_task.c
irq_work.c
itimer.c
jump_label.c jump_label: Check entries limit in __jump_label_update 2011-05-25 19:56:36 -04:00
kallsyms.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kexec.c
kfifo.c
kmod.c Merge branch 'next' into for-linus 2011-05-24 22:55:24 +10:00
kprobes.c
ksysfs.c
kthread.c cpuset: Fix cpuset_cpus_allowed_fallback(), don't update tsk->rt.nr_cpus_allowed 2011-05-28 17:02:57 +02:00
latencytop.c
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c
Makefile cgroup: remove the ns_cgroup 2011-05-26 17:12:34 -07:00
module.c
mutex-debug.c
mutex-debug.h
mutex.c lockdep, mutex: provide mutex_lock_nest_lock 2011-05-25 08:39:17 -07:00
mutex.h
notifier.c
nsproxy.c cgroup: remove the ns_cgroup 2011-05-26 17:12:34 -07:00
padata.c
panic.c
params.c
pid_namespace.c
pid.c
pm_qos_params.c Merge branch 'idle-release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-idle-2.6 2011-05-29 11:18:09 -07:00
posix-cpu-timers.c
posix-timers.c posix-timers: RCU conversion 2011-05-24 12:10:51 +02:00
printk.c printk: allocate kernel log buffer earlier 2011-05-25 08:39:48 -07:00
profile.c kernel/profile.c: remove some duplicate code from profile_hits() 2011-05-26 17:12:37 -07:00
ptrace.c ptrace: ptrace_resume() shouldn't wake up !TASK_TRACED thread 2011-05-25 19:20:21 +02:00
range.c
rcupdate.c
rcutiny_plugin.h
rcutiny.c
rcutorture.c
rcutree_plugin.h rcu: Cure load woes 2011-05-31 10:01:48 +02:00
rcutree_trace.c rcu: Decrease memory-barrier usage based on semi-formal proof 2011-05-26 09:42:23 -07:00
rcutree.c rcu: Cure load woes 2011-05-31 10:01:48 +02:00
rcutree.h rcu: Remove waitqueue usage for cpu, node, and boost kthreads 2011-05-28 17:41:52 +02:00
relay.c
res_counter.c
resource.c
rtmutex_common.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex-tester.c
rtmutex.c
rtmutex.h
rwsem.c
sched_autogroup.c
sched_autogroup.h
sched_clock.c
sched_cpupri.c
sched_cpupri.h
sched_debug.c
sched_fair.c sched: Fix ->min_vruntime calculation in dequeue_entity() 2011-05-28 17:02:56 +02:00
sched_features.h
sched_idletask.c
sched_rt.c sched: More sched_domain iterations fixes 2011-05-28 17:02:54 +02:00
sched_stats.h sched: More sched_domain iterations fixes 2011-05-28 17:02:54 +02:00
sched_stoptask.c
sched.c cpuset: Fix cpuset_cpus_allowed_fallback(), don't update tsk->rt.nr_cpus_allowed 2011-05-28 17:02:57 +02:00
seccomp.c
semaphore.c
signal.c signal: sys_pause() should check signal_pending() 2011-05-25 19:22:27 +02:00
smp.c
softirq.c
spinlock.c
srcu.c
stacktrace.c
stop_machine.c
sys_ni.c
sys.c
sysctl_binary.c
sysctl_check.c
sysctl.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/cmetcalf/linux-tile 2011-05-25 15:35:32 -07:00
taskstats.c
test_kprobes.c
time.c
timeconst.pl
timer.c
tracepoint.c
tsacct.c
uid16.c
up.c
user_namespace.c
user-return-notifier.c
user.c
utsname_sysctl.c
utsname.c
wait.c
watchdog.c kernel/watchdog.c: Use proper ANSI C prototypes 2011-05-23 21:07:40 -07:00
workqueue_sched.h
workqueue.c Merge branch 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu 2011-05-24 11:53:42 -07:00