linux/kernel/time
Preeti U Murthy a127d2bcf1 timers/tick/broadcast-hrtimer: Fix suspicious RCU usage in idle loop
The hrtimer mode of broadcast queues hrtimers in the idle entry
path so as to wakeup cpus in deep idle states. The associated
call graph is :

	cpuidle_idle_call()
	|____ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, ....))
	     |_____tick_broadcast_set_event()
		   |____clockevents_program_event()
			|____bc_set_next()

The hrtimer_{start/cancel} functions call into tracing which uses RCU.
But it is not legal to call into RCU in cpuidle because it is one of the
quiescent states. Hence protect this region with RCU_NONIDLE which informs
RCU that the cpu is momentarily non-idle.

As an aside it is helpful to point out that the clock event device that is
programmed here is not a per-cpu clock device; it is a
pseudo clock device, used by the broadcast framework alone.
The per-cpu clock device programming never goes through bc_set_next().

Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: linuxppc-dev@ozlabs.org
Cc: mpe@ellerman.id.au
Cc: tglx@linutronix.de
Link: http://lkml.kernel.org/r/20150318104705.17763.56668.stgit@preeti.in.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-03-23 10:50:05 +01:00
..
alarmtimer.c all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
clockevents.c clockevents: Prevent shift out of bounds 2014-10-25 10:43:15 +02:00
clocksource.c time: move the timecounter/cyclecounter code into its own file. 2014-12-30 18:29:25 -05:00
hrtimer.c all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
itimer.c time/timers: Move all time(r) related files into kernel/time 2014-06-23 11:22:35 +02:00
jiffies.c time: Fix overflow when HZ is smaller than 60 2014-02-06 16:01:40 +01:00
Kconfig clocksource: Move cycle_last validation to core code 2014-07-23 15:01:51 -07:00
Makefile time: move the timecounter/cyclecounter code into its own file. 2014-12-30 18:29:25 -05:00
ntp_internal.h timekeeping: Convert timekeeping core to use timespec64s 2014-07-23 10:17:54 -07:00
ntp.c ntp: Fixup adjtimex freq validation on 32-bit systems 2015-02-18 14:50:10 +01:00
posix-clock.c kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructure 2011-10-31 19:30:05 -04:00
posix-cpu-timers.c all arches, signal: move restart_block to struct task_struct 2015-02-12 18:54:12 -08:00
posix-timers.c posix-timers: Fix stack info leak in timer_create() 2014-10-25 10:43:15 +02:00
sched_clock.c sched_clock: Avoid corrupting hrtimer tree during suspend 2014-07-24 12:02:49 +02:00
test_udelay.c time: Rename udelay_test.c to test_udelay.c 2014-11-21 11:59:55 -08:00
tick-broadcast-hrtimer.c timers/tick/broadcast-hrtimer: Fix suspicious RCU usage in idle loop 2015-03-23 10:50:05 +01:00
tick-broadcast.c time: Replace __get_cpu_var uses 2014-08-26 13:45:44 -04:00
tick-common.c PM / sleep: Make it possible to quiesce timers during suspend-to-idle 2015-02-15 19:40:09 +01:00
tick-internal.h nohz: Move nohz full init call to tick init 2014-09-13 18:34:44 +02:00
tick-oneshot.c time: Replace __get_cpu_var uses 2014-08-26 13:45:44 -04:00
tick-sched.c time: use %*pb[l] to print bitmaps including cpumasks and nodemasks 2015-02-13 21:21:37 -08:00
time.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2015-01-25 17:47:34 -08:00
timeconst.bc time/timers: Move all time(r) related files into kernel/time 2014-06-23 11:22:35 +02:00
timeconv.c time: add function to convert between calendar time and broken-down time for universal use 2009-09-24 07:20:56 -07:00
timecounter.c timecounter: keep track of accumulated fractional nanoseconds 2014-12-30 18:29:27 -05:00
timekeeping_debug.c timekeeping: Convert timekeeping core to use timespec64s 2014-07-23 10:17:54 -07:00
timekeeping_internal.h clocksource: Move cycle_last validation to core code 2014-07-23 15:01:51 -07:00
timekeeping.c PM / sleep: Make it possible to quiesce timers during suspend-to-idle 2015-02-15 19:40:09 +01:00
timekeeping.h PM / sleep: Make it possible to quiesce timers during suspend-to-idle 2015-02-15 19:40:09 +01:00
timer_list.c timer_list: correct the iterator for timer_list 2013-08-28 19:26:38 -07:00
timer_stats.c timer stats: Add a 'Collection: active/inactive' line to timer usage statistics 2013-10-10 09:59:25 +02:00
timer.c rcu: Remove "cpu" argument to rcu_check_callbacks() 2014-11-03 19:20:11 -08:00