diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2026-02-24 17:37:58 +0100 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2026-02-27 16:40:13 +0100 |
| commit | a43b4856bc039675165a50d9ef5f41b28520f0f4 (patch) | |
| tree | c5782d97f53f421ba74e2093e5f36d185fad2b4d /kernel/time | |
| parent | 9e07a9c980eaa93fd1bba722d31eeb4bf0cbbfb4 (diff) | |
hrtimer: Prepare stubs for deferred rearming
The hrtimer interrupt expires timers and at the end of the interrupt it
rearms the clockevent device for the next expiring timer.
That's obviously correct, but in the case that a expired timer set
NEED_RESCHED the return from interrupt ends up in schedule(). If HRTICK is
enabled then schedule() will modify the hrtick timer, which causes another
reprogramming of the hardware.
That can be avoided by deferring the rearming to the return from interrupt
path and if the return results in a immediate schedule() invocation then it
can be deferred until the end of schedule().
To make this correct the affected code parts need to be made aware of this.
Provide empty stubs for the deferred rearming mechanism, so that the
relevant code changes for entry, softirq and scheduler can be split up into
separate changes independent of the actual enablement in the hrtimer code.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260224163431.000891171@kernel.org
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/Kconfig | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/time/Kconfig b/kernel/time/Kconfig index e1968ab8b37f..b95bfee3f592 100644 --- a/kernel/time/Kconfig +++ b/kernel/time/Kconfig @@ -58,6 +58,10 @@ config GENERIC_CLOCKEVENTS_COUPLED_INLINE config GENERIC_CMOS_UPDATE bool +# Deferred rearming of the hrtimer interrupt +config HRTIMER_REARM_DEFERRED + def_bool n + # Select to handle posix CPU timers from task_work # and not from the timer interrupt context config HAVE_POSIX_CPU_TIMERS_TASK_WORK |