linux/kernel/time
Anna-Maria Gleixner 3f0b9e8eec hrtimer: Store running timer in hrtimer_clock_base
The pointer to the currently running timer is stored in hrtimer_cpu_base
before the base lock is dropped and the callback is invoked.

This results in two levels of indirections and the upcoming support for
softirq based hrtimer requires splitting the "running" storage into soft
and hard IRQ context expiry.

Storing both in the cpu base would require conditionals in all code paths
accessing that information.

It's possible to have a per clock base sequence count and running pointer
without changing the semantics of the related mechanisms because the timer
base pointer cannot be changed while a timer is running the callback.

Unfortunately this makes cpu_clock base larger than 32 bytes on 32-bit
kernels. Instead of having huge gaps due to alignment, remove the alignment
and let the compiler pack CPU base for 32-bit kernels. The resulting cache access
patterns are fortunately not really different from the current
behaviour. On 64-bit kernels the 64-byte alignment stays and the behaviour is
unchanged. This was determined by analyzing the resulting layout and
looking at the number of cache lines involved for the frequently used
clocks.

Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: keescook@chromium.org
Link: http://lkml.kernel.org/r/20171221104205.7269-12-anna-maria@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-01-16 02:35:46 +01:00
..
alarmtimer.c alarmtimer: Ensure RTC module is not unloaded 2017-08-31 21:36:45 +02:00
clockevents.c clockevents: Retry programming min delta up to 10 times 2017-10-19 16:29:15 +02:00
clocksource.c treewide: setup_timer() -> timer_setup() 2017-11-21 15:57:07 -08:00
hrtimer.c hrtimer: Store running timer in hrtimer_clock_base 2018-01-16 02:35:46 +01:00
itimer.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
jiffies.c jiffies: Revert bogus conversion of NSEC_PER_SEC to TICK_NSEC 2017-03-07 11:03:28 +01:00
Kconfig sched/isolation: Make CONFIG_NO_HZ_FULL select CONFIG_CPU_ISOLATION 2017-12-18 13:46:42 +01:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ntp_internal.h Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-13 17:56:58 -08:00
ntp.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-13 17:56:58 -08:00
posix-clock.c posix-timers: Prevent UB from shifting negative signed value 2018-01-04 14:57:10 +01:00
posix-cpu-timers.c posix-cpu-timers: Make set_process_cpu_timer() more robust 2018-01-14 20:50:59 +01:00
posix-stubs.c posix-stubs: Use get_timespec64() and put_timespec64() 2017-10-17 17:22:27 +02:00
posix-timers.c posix-timer: Properly check sigevent->sigev_notify 2017-12-15 11:08:40 +01:00
posix-timers.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sched_clock.c timers, sched_clock: Update timeout for clock wrap 2017-03-23 12:30:27 -07:00
test_udelay.c time: Avoid timespec in udelay_test 2016-06-20 12:47:26 -07:00
tick-broadcast-hrtimer.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tick-broadcast.c tick/broadcast: Make tick_broadcast_setup_oneshot() static 2017-06-12 18:56:01 +02:00
tick-common.c ktime: Cleanup ktime_set() usage 2016-12-25 17:21:22 +01:00
tick-internal.h hrtimer: Optimize the hrtimer code by using static keys for migration_enable/nohz_active 2018-01-16 02:35:44 +01:00
tick-oneshot.c clockevents: Update clockevents device next_event on stop 2017-11-01 18:20:17 +01:00
tick-sched.c hrtimer: Optimize the hrtimer code by using static keys for migration_enable/nohz_active 2018-01-16 02:35:44 +01:00
tick-sched.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
time.c Merge branch 'fortglx/4.15/time' of https://git.linaro.org/people/john.stultz/linux into timers/core 2017-10-31 23:17:28 +01:00
timeconst.bc time: Introduce jiffies64_to_nsecs() 2017-02-01 09:13:45 +01:00
timeconv.c
timecounter.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
timekeeping_debug.c PM / timekeeping: Print debug messages when requested 2017-07-23 00:03:43 +02:00
timekeeping_internal.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
timekeeping.c timekeeping: Remove CONFIG_GENERIC_TIME_VSYSCALL_OLD 2017-11-14 11:20:25 +01:00
timekeeping.h Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-11-13 17:56:58 -08:00
timer_list.c timer/debug: Change /proc/timer_list from 0444 to 0400 2017-11-13 16:04:06 +01:00
timer.c hrtimer: Optimize the hrtimer code by using static keys for migration_enable/nohz_active 2018-01-16 02:35:44 +01:00