diff options
| author | Anna-Maria Behnsen <anna-maria@linutronix.de> | 2024-02-21 10:05:48 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2024-02-22 17:52:32 +0100 |
| commit | b2cf7507e18649a30512515ec0ca89f26b2c2d0f (patch) | |
| tree | 0ee6441f5893dfffc3107cbe22bd72ceca24139a /include/linux/timer.h | |
| parent | 36e40df35d2c1891fe58241640c7c95de4aa739b (diff) | |
timers: Always queue timers on the local CPU
The timer pull model is in place so we can remove the heuristics which try
to guess the best target CPU at enqueue/modification time.
All non pinned timers are queued on the local CPU in the separate storage
and eventually pulled at expiry time to a remote CPU.
Originally-by: Richard Cochran (linutronix GmbH) <richardcochran@gmail.com>
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/20240221090548.36600-21-anna-maria@linutronix.de
Diffstat (limited to 'include/linux/timer.h')
| -rw-r--r-- | include/linux/timer.h | 14 |
1 files changed, 4 insertions, 10 deletions
diff --git a/include/linux/timer.h b/include/linux/timer.h index 2be8be6dd317..14a633ba61d6 100644 --- a/include/linux/timer.h +++ b/include/linux/timer.h @@ -36,16 +36,10 @@ * workqueue locking issues. It's not meant for executing random crap * with interrupts disabled. Abuse is monitored! * - * @TIMER_PINNED: A pinned timer will not be affected by any timer - * placement heuristics (like, NOHZ) and will always expire on the CPU - * on which the timer was enqueued. - * - * Note: Because enqueuing of timers can migrate the timer from one - * CPU to another, pinned timers are not guaranteed to stay on the - * initialy selected CPU. They move to the CPU on which the enqueue - * function is invoked via mod_timer() or add_timer(). If the timer - * should be placed on a particular CPU, then add_timer_on() has to be - * used. + * @TIMER_PINNED: A pinned timer will always expire on the CPU on which the + * timer was enqueued. When a particular CPU is required, add_timer_on() + * has to be used. Enqueue via mod_timer() and add_timer() is always done + * on the local CPU. */ #define TIMER_CPUMASK 0x0003FFFF #define TIMER_MIGRATING 0x00040000 |