diff options
| author | Frederic Weisbecker <frederic@kernel.org> | 2022-02-02 01:01:07 +0100 |
|---|---|---|
| committer | Frederic Weisbecker <frederic@kernel.org> | 2022-03-07 23:01:19 +0100 |
| commit | a1ff03cd6fb9c501fff63a4a2bface9adcfa81cd (patch) | |
| tree | 5a5e4af9948395d52664857409bb6d4c4811efe8 /kernel/time/tick-sched.h | |
| parent | 58dedf0a4782ce42b4d31f1f62e5ad80a1b73d72 (diff) | |
tick: Detect and fix jiffies update stall
On some rare cases, the timekeeper CPU may be delaying its jiffies
update duty for a while. Known causes include:
* The timekeeper is waiting on stop_machine in a MULTI_STOP_DISABLE_IRQ
or MULTI_STOP_RUN state. Disabled interrupts prevent from timekeeping
updates while waiting for the target CPU to complete its
stop_machine() callback.
* The timekeeper vcpu has VMEXIT'ed for a long while due to some overload
on the host.
Detect and fix these situations with emergency timekeeping catchups.
Original-patch-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel/time/tick-sched.h')
| -rw-r--r-- | kernel/time/tick-sched.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/time/tick-sched.h b/kernel/time/tick-sched.h index d952ae393423..504649513399 100644 --- a/kernel/time/tick-sched.h +++ b/kernel/time/tick-sched.h @@ -49,6 +49,8 @@ enum tick_nohz_mode { * @timer_expires_base: Base time clock monotonic for @timer_expires * @next_timer: Expiry time of next expiring timer for debugging purpose only * @tick_dep_mask: Tick dependency mask - is set, if someone needs the tick + * @last_tick_jiffies: Value of jiffies seen on last tick + * @stalled_jiffies: Number of stalled jiffies detected across ticks */ struct tick_sched { struct hrtimer sched_timer; @@ -77,6 +79,8 @@ struct tick_sched { u64 next_timer; ktime_t idle_expires; atomic_t tick_dep_mask; + unsigned long last_tick_jiffies; + unsigned int stalled_jiffies; }; extern struct tick_sched *tick_get_tick_sched(int cpu); |