linux-stable/kernel/time
Anna-Maria Behnsen e2e1d724e9 timers: Move marking timer bases idle into tick_nohz_stop_tick()
The timer base is marked idle when get_next_timer_interrupt() is
executed. But the decision whether the tick will be stopped and whether the
system is able to go idle is done later. When the timer bases is marked
idle and a new first timer is enqueued remote an IPI is raised. Even if it
is not required because the tick is not stopped and the timer base is
evaluated again at the next tick.

To prevent this, the timer base is marked idle in tick_nohz_stop_tick() and
get_next_timer_interrupt() is streamlined by only looking for the next timer
interrupt. All other work is postponed to timer_base_try_to_set_idle() which is
called by tick_nohz_stop_tick(). timer_base_try_to_set_idle() never resets
timer_base::is_idle state. This is done when the tick is restarted via
tick_nohz_restart_sched_tick().

With this, tick_sched::tick_stopped and timer_base::is_idle are always in
sync. So there is no longer the need to execute timer_clear_idle() in
tick_nohz_idle_retain_tick(). This was required before, as
tick_nohz_next_event() set timer_base::is_idle even if the tick would not be
stopped. So timer_clear_idle() is only executed, when timer base is idle. So the
check whether timer base is idle, is now no longer required as well.

While at it fix some nearby whitespace damage as well.

Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20240221090548.36600-4-anna-maria@linutronix.de
2024-02-22 17:52:30 +01:00
..
alarmtimer.c alarmtimer: Use maximum alarm time for suspend 2023-10-09 15:03:28 +02:00
clockevents.c clockevents: Make clockevents_subsys const 2024-02-07 15:11:24 +01:00
clocksource-wdtest.c clocksource: Scale the watchdog read retries automatically 2024-02-21 12:00:42 +01:00
clocksource.c clocksource: Scale the watchdog read retries automatically 2024-02-21 12:00:42 +01:00
hrtimer.c Merge tag 'v6.8-rc5' into timers/core, to resolve conflict 2024-02-19 22:27:57 +01:00
itimer.c time: Prevent undefined behaviour in timespec64_to_ns() 2020-10-26 11:48:11 +01:00
jiffies.c clocksource: Make clocksource watchdog test safe for slow-HZ systems 2021-08-28 17:01:32 +02:00
Kconfig clocksource: Loosen clocksource watchdog constraints 2023-01-03 20:43:45 -08:00
Makefile time: Improve performance of time64_to_tm() 2021-06-24 11:51:59 +02:00
namespace.c vdso/timens: Refactor copy-pasted find_timens_vvar_page() helper into one copy 2022-12-01 11:35:40 +01:00
ntp_internal.h ntp: Make the RTC synchronization more reliable 2020-12-11 10:40:52 +01:00
ntp.c timekeeping, clocksource: Fix various typos in comments 2021-03-22 23:06:48 +01:00
posix-clock.c posix-clock: introduce posix_clock_context concept 2023-10-15 20:07:52 +01:00
posix-cpu-timers.c posix-cpu-timers: Implement the missing timer_wait_running callback 2023-04-21 15:34:33 +02:00
posix-stubs.c posix-timers: Get rid of [COMPAT_]SYS_NI() uses 2023-12-20 21:30:27 -08:00
posix-timers.c posix-timers: Refer properly to CONFIG_HIGH_RES_TIMERS 2023-06-18 22:41:53 +02:00
posix-timers.h posix-clocks: Introduce clock_get_ktime() callback 2020-01-14 12:20:51 +01:00
sched_clock.c time/sched_clock: Provide sched_clock_noinstr() 2023-06-05 21:11:04 +02:00
test_udelay.c time/debug: Fix memory leak with using debugfs_lookup() 2023-02-09 20:12:27 +01:00
tick-broadcast-hrtimer.c time/tick-broadcast: Remove RCU_NONIDLE() usage 2023-01-13 11:48:16 +01:00
tick-broadcast.c tick/broadcast: Make broadcast device replacement work correctly 2023-05-08 23:18:16 +02:00
tick-common.c tick/common: Align tick period during sched_timer setup 2023-06-16 20:45:28 +02:00
tick-internal.h timers: Move marking timer bases idle into tick_nohz_stop_tick() 2024-02-22 17:52:30 +01:00
tick-legacy.c timekeeping: remove xtime_update 2020-10-30 21:57:07 +01:00
tick-oneshot.c time: Fix various kernel-doc problems 2023-01-03 11:07:58 +01:00
tick-sched.c timers: Move marking timer bases idle into tick_nohz_stop_tick() 2024-02-22 17:52:30 +01:00
tick-sched.h timers/nohz: Protect idle/iowait sleep time under seqcount 2023-04-18 16:35:12 +02:00
time_test.c time/kunit: Use correct format specifier 2024-02-21 12:00:42 +01:00
time.c time: add kernel-doc in time.c 2023-07-14 13:47:07 -06:00
timeconst.bc time: Add SPDX license identifiers 2018-11-23 11:51:20 +01:00
timeconv.c time: Improve performance of time64_to_tm() 2021-06-24 11:51:59 +02:00
timecounter.c time/timecounter: Mark 1st argument of timecounter_cyc2time() as const 2021-04-16 21:03:50 +02:00
timekeeping_debug.c timekeeping/debug: No need to check return value of debugfs_create functions 2019-01-29 20:08:41 +01:00
timekeeping_internal.h timekeeping/vsyscall: Provide vdso_update_begin/end() 2020-08-06 10:57:30 +02:00
timekeeping.c timekeeping: Fix cross-timestamp interpolation for non-x86 2024-02-19 12:18:51 +01:00
timekeeping.h asm-generic: cross-architecture timer cleanup 2020-12-16 00:07:17 -08:00
timer_list.c timer_list: Print name of per-cpu wakeup device 2021-05-31 17:04:49 +02:00
timer.c timers: Move marking timer bases idle into tick_nohz_stop_tick() 2024-02-22 17:52:30 +01:00
vsyscall.c timekeeping, clocksource: Fix various typos in comments 2021-03-22 23:06:48 +01:00