diff options
| author | Stian Halseth <stian@itx.no> | 2026-10-07 16:29:50 +0200 |
|---|---|---|
| committer | Peter Zijlstra <peterz@infradead.org> | 2026-10-16 09:49:03 +0200 |
| commit | 96a494c9cfd8f4bb7b1a7a70275426db71cf98aa (patch) | |
| tree | a4bcb7d5a6850ee0bf4f64a52a45f01800fb3500 /include/linux | |
| parent | 6f88f6cbb0472a8481ba560578a1d7c8d802eba7 (diff) | |
| download | linux-96a494c9cfd8f4bb7b1a7a70275426db71cf98aa.tar.gz linux-96a494c9cfd8f4bb7b1a7a70275426db71cf98aa.zip | |
sched/cputime: Don't account idle time twice after dyntick-idle
On idle exit the dyntick-idle accounting accounts the time up to now,
then the tick is restarted on its old period. The first tick accounts a
whole TICK_NSEC to whatever runs, although the part of that period
before the idle exit has just been accounted as idle time, or with
IRQ_TIME_ACCOUNTING as IRQ time. That is up to a full tick per idle
exit, and /proc/stat reports more idle time than wall time.
Record how much of the current tick period dyntick-idle has accounted,
and leave it out of the tick that ends the period.
Fixes: cf6444c3e1bb7 ("tick/sched: Unify idle cputime accounting")
Signed-off-by: Stian Halseth <stian@itx.no>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20261004142724.3896396-1-stian@itx.no/
Link: https://patch.msgid.link/20261007142950.547604-1-stian@itx.no
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/kernel_stat.h | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h index c1e85550bf12..9f0f91dc8d7d 100644 --- a/include/linux/kernel_stat.h +++ b/include/linux/kernel_stat.h @@ -40,6 +40,9 @@ struct kernel_cpustat { seqcount_t idle_sleeptime_seq; u64 idle_entrytime; u64 idle_stealtime[2]; + u64 idle_dyntick_entry; + u64 idle_tick_period; + u64 idle_tick_overlap; #endif u64 cpustat[NR_STATS]; }; @@ -111,7 +114,7 @@ static inline unsigned long kstat_cpu_irqs_sum(unsigned int cpu) #ifdef CONFIG_HAVE_VIRT_CPU_ACCOUNTING_IDLE static inline void kcpustat_dyntick_start(u64 now) { } -static inline void kcpustat_dyntick_stop(u64 now) { } +static inline void kcpustat_dyntick_stop(u64 now, u64 tick_start) { } static inline void kcpustat_irq_enter(u64 now) { } static inline void kcpustat_irq_exit(u64 now) { } static inline bool kcpustat_idle_dyntick(void) { return false; } @@ -132,7 +135,7 @@ static inline u64 kcpustat_field_iowait(int cpu) #else /* !CONFIG_HAVE_VIRT_CPU_ACCOUNTING_IDLE */ extern void kcpustat_dyntick_start(u64 now); -extern void kcpustat_dyntick_stop(u64 now); +extern void kcpustat_dyntick_stop(u64 now, u64 tick_start); extern void kcpustat_irq_enter(u64 now); extern void kcpustat_irq_exit(u64 now); extern u64 kcpustat_field_idle(int cpu); |