diff options
| author | Thomas Gleixner <tglx@kernel.org> | 2026-04-14 22:55:01 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@kernel.org> | 2026-04-16 21:22:04 +0200 |
| commit | 4096fd0e8eaea13ebe5206700b33f49635ae18e5 (patch) | |
| tree | dce5f4f328ff5a081a108b6fdf5402cbf6a9ae7d | |
| parent | 1d51b370a0f8f642f4fc84c795fbedac0fcdbbd2 (diff) | |
clockevents: Add missing resets of the next_event_forced flag
The prevention mechanism against timer interrupt starvation missed to reset
the next_event_forced flag in a couple of places:
- When the clock event state changes. That can cause the flag to be
stale over a shutdown/startup sequence
- When a non-forced event is armed, which then prevents rearming before
that event. If that event is far out in the future this will cause
missed timer interrupts.
- In the suspend wakeup handler.
That led to stalls which have been reported by several people.
Add the missing resets, which fixes the problems for the reporters.
Fixes: d6e152d905bd ("clockevents: Prevent timer interrupt starvation")
Reported-by: Hanabishi <i.r.e.c.c.a.k.u.n+kernel.org@gmail.com>
Reported-by: Eric Naim <dnaim@cachyos.org>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Tested-by: Hanabishi <i.r.e.c.c.a.k.u.n+kernel.org@gmail.com>
Tested-by: Eric Naim <dnaim@cachyos.org>
Cc: stable@vger.kernel.org
Closes: https://lore.kernel.org/68d1e9ac-2780-4be3-8ee3-0788062dd3a4@gmail.com
Link: https://patch.msgid.link/87340xfeje.ffs@tglx
| -rw-r--r-- | kernel/time/clockevents.c | 7 | ||||
| -rw-r--r-- | kernel/time/tick-broadcast.c | 1 |
2 files changed, 7 insertions, 1 deletions
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index b4d730604972..5e22697b098d 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -94,6 +94,9 @@ static int __clockevents_switch_state(struct clock_event_device *dev, if (dev->features & CLOCK_EVT_FEAT_DUMMY) return 0; + /* On state transitions clear the forced flag unconditionally */ + dev->next_event_forced = 0; + /* Transition with new state-specific callbacks */ switch (state) { case CLOCK_EVT_STATE_DETACHED: @@ -366,8 +369,10 @@ int clockevents_program_event(struct clock_event_device *dev, ktime_t expires, b if (delta > (int64_t)dev->min_delta_ns) { delta = min(delta, (int64_t) dev->max_delta_ns); cycles = ((u64)delta * dev->mult) >> dev->shift; - if (!dev->set_next_event((unsigned long) cycles, dev)) + if (!dev->set_next_event((unsigned long) cycles, dev)) { + dev->next_event_forced = 0; return 0; + } } if (dev->next_event_forced) diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 7e57fa31ee26..115e0bf01276 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -108,6 +108,7 @@ static struct clock_event_device *tick_get_oneshot_wakeup_device(int cpu) static void tick_oneshot_wakeup_handler(struct clock_event_device *wd) { + wd->next_event_forced = 0; /* * If we woke up early and the tick was reprogrammed in the * meantime then this may be spurious but harmless. |