kernel_optimize_test/kernel/time
Frederic Weisbecker 31cd0e119d timers: Recalculate next timer interrupt only when necessary
The nohz tick code recalculates the timer wheel's next expiry on each idle
loop iteration.

On the other hand, the base next expiry is now always cached and updated
upon timer enqueue and execution. Only timer dequeue may leave
base->next_expiry out of date (but then its stale value won't ever go past
the actual next expiry to be recalculated).

Since recalculating the next_expiry isn't a free operation, especially when
the last wheel level is reached to find out that no timer has been enqueued
at all, reuse the next expiry cache when it is known to be reliable, which
it is most of the time.

Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20200723151641.12236-1-frederic@kernel.org
2020-07-24 12:49:40 +02:00
..
alarmtimer.c alarmtimer: Make alarmtimer_get_rtcdev() a stub when CONFIG_RTC_CLASS=n 2020-01-24 21:03:53 +01:00
clockevents.c
clocksource.c clocksource: Remove obsolete ifdef 2020-06-09 16:36:47 +02:00
hrtimer.c hrtimer: Don't dereference the hrtimer pointer after the callback 2020-04-01 13:20:14 +02:00
itimer.c y2038: rename itimerval to __kernel_old_itimerval 2019-12-18 18:07:33 +01:00
jiffies.c timekeeping: Split jiffies seqlock 2020-03-21 16:00:23 +01:00
Kconfig
Makefile ns: Introduce Time Namespace 2020-01-14 12:20:48 +01:00
namespace.c nsproxy: add struct nsset 2020-05-09 13:57:12 +02:00
ntp_internal.h
ntp.c ntp/y2038: Remove incorrect time_t truncation 2019-11-12 08:13:44 +01:00
posix-clock.c posix-clocks: Rename the clock_get() callback to clock_get_timespec() 2020-01-14 12:20:49 +01:00
posix-cpu-timers.c posix-cpu-timers: Replace __get_task_for_clock with pid_for_clock 2020-04-29 08:14:41 -05:00
posix-stubs.c posix-timers: Make clock_nanosleep() time namespace aware 2020-01-14 12:20:55 +01:00
posix-timers.c posix-timers: Pass lockdep expression to RCU lists 2020-02-17 20:12:19 +01:00
posix-timers.h posix-clocks: Introduce clock_get_ktime() callback 2020-01-14 12:20:51 +01:00
sched_clock.c time/sched_clock: Expire timer in hardirq context 2020-03-19 09:45:08 +01:00
test_udelay.c
tick-broadcast-hrtimer.c tick: broadcast-hrtimer: Fix a race in bc_set_next 2019-09-27 14:45:55 +02:00
tick-broadcast.c
tick-common.c timekeeping: Split jiffies seqlock 2020-03-21 16:00:23 +01:00
tick-internal.h
tick-oneshot.c
tick-sched.c lockdep: Annotate irq_work 2020-03-21 16:00:24 +01:00
tick-sched.h
time.c y2038: remove unused time32 interfaces 2020-02-21 11:22:15 -08:00
timeconst.bc
timeconv.c
timecounter.c
timekeeping_debug.c
timekeeping_internal.h
timekeeping.c x86/mce: Address objtools noinstr complaints 2020-06-11 15:15:02 +02:00
timekeeping.h timekeeping: Split jiffies seqlock 2020-03-21 16:00:23 +01:00
timer_list.c
timer.c timers: Recalculate next timer interrupt only when necessary 2020-07-24 12:49:40 +02:00
vsyscall.c lib/vdso: Avoid highres update if clocksource is not VDSO capable 2020-02-17 20:12:17 +01:00