linux/kernel/time
Stephen Boyd 70e5975d3a clockevents: Prefer CPU local devices over global devices
On an SMP system with only one global clockevent and a dummy
clockevent per CPU we run into problems. We want the dummy
clockevents to be registered as the per CPU tick devices, but
we can only achieve that if we register the dummy clockevents
before the global clockevent or if we artificially inflate the
rating of the dummy clockevents to be higher than the rating
of the global clockevent. Failure to do so leads to boot
hangs when the dummy timers are registered on all other CPUs
besides the CPU that accepted the global clockevent as its tick
device and there is no broadcast timer to poke the dummy
devices.

If we're registering multiple clockevents and one clockevent is
global and the other is local to a particular CPU we should
choose to use the local clockevent regardless of the rating of
the device. This way, if the clockevent is a dummy it will take
the tick device duty as long as there isn't a higher rated tick
device and any global clockevent will be bumped out into
broadcast mode, fixing the problem described above.

Reported-and-tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: soren.brinkmann@xilinx.com
Cc: John Stultz <john.stultz@linaro.org>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Cc: John Stultz <john.stultz@linaro.org>
Link: http://lkml.kernel.org/r/20130613183950.GA32061@codeaurora.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2013-06-24 22:27:36 +02:00
..
alarmtimer.c alarmtimer: Export symbols of functions declared in linux/alarmtimer.h 2013-06-12 14:02:12 -07:00
clockevents.c clockevents: Implement unbind functionality 2013-05-16 11:09:18 +02:00
clocksource.c clocksource: Implement clocksource_select_fallback() for CONFIG_ARCH_USES_GETTIMEOFFSET=y 2013-05-28 09:48:46 +02:00
jiffies.c time: Kill xtime_lock, replacing it with jiffies_lock 2012-11-13 14:08:23 -05:00
Kconfig Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-05-15 14:05:17 -07:00
Makefile sched_clock: Make ARM's sched_clock generic for all architectures 2013-06-12 14:02:13 -07:00
ntp_internal.h ntp: Rework do_adjtimex to take timespec and tai arguments 2013-04-04 13:18:15 -07:00
ntp.c ntp: Remove ntp_lock, using the timekeeping locks to protect ntp state 2013-04-04 13:18:17 -07:00
posix-clock.c kernel: Fix files explicitly needing EXPORT_SYMBOL infrastructure 2011-10-31 19:30:05 -04:00
sched_clock.c ARM: sched_clock: Load cycle count after epoch stabilizes 2013-06-17 15:56:11 -07:00
tick-broadcast.c clockevents: Split out selection logic 2013-05-16 11:09:17 +02:00
tick-common.c clockevents: Prefer CPU local devices over global devices 2013-06-24 22:27:36 +02:00
tick-internal.h clockevents: Define CS_NAME_LEN unconditionally 2013-05-28 09:28:02 +02:00
tick-oneshot.c clockevents: Make minimum delay adjustments configurable 2011-09-08 11:10:56 +02:00
tick-sched.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2013-05-15 14:05:17 -07:00
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
timekeeping_debug.c power: Add option to log time spent in suspend 2013-05-29 12:57:34 -07:00
timekeeping_internal.h power: Add option to log time spent in suspend 2013-05-29 12:57:34 -07:00
timekeeping.c power: Add option to log time spent in suspend 2013-05-29 12:57:34 -07:00
timer_list.c timer_list: Convert timer list to be a proper seq_file 2013-04-17 20:51:02 +02:00
timer_stats.c locking, timer_stats: Annotate table_lock as raw 2011-09-13 11:12:00 +02:00