diff options
| author | Wanpeng Li <[email protected]> | 2016-06-13 18:32:45 +0800 |
|---|---|---|
| committer | Ingo Molnar <[email protected]> | 2016-06-14 11:13:15 +0200 |
| commit | 3d89e5478bf550a50c99e93adf659369798263b0 (patch) | |
| tree | ed64193221dbc18db91101aa6a060a710d986c52 | |
| parent | 2348140d58f4f4245e9635ea8f1a77e940a4d877 (diff) | |
sched/cputime: Fix prev steal time accouting during CPU hotplug
Commit:
e9532e69b8d1 ("sched/cputime: Fix steal time accounting vs. CPU hotplug")
... set rq->prev_* to 0 after a CPU hotplug comes back, in order to
fix the case where (after CPU hotplug) steal time is smaller than
rq->prev_steal_time.
However, this should never happen. Steal time was only smaller because of the
KVM-specific bug fixed by the previous patch. Worse, the previous patch
triggers a bug on CPU hot-unplug/plug operation: because
rq->prev_steal_time is cleared, all of the CPU's past steal time will be
accounted again on hot-plug.
Since the root cause has been fixed, we can just revert commit e9532e69b8d1.
Signed-off-by: Wanpeng Li <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Paolo Bonzini <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Radim Krčmář <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Fixes: 'commit e9532e69b8d1 ("sched/cputime: Fix steal time accounting vs. CPU hotplug")'
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
| -rw-r--r-- | kernel/sched/core.c | 1 | ||||
| -rw-r--r-- | kernel/sched/sched.h | 13 |
2 files changed, 0 insertions, 14 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index 13d0896aff87..c1b537bc4b90 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -7227,7 +7227,6 @@ static void sched_rq_cpu_starting(unsigned int cpu) struct rq *rq = cpu_rq(cpu); rq->calc_load_update = calc_load_update; - account_reset_rq(rq); update_max_interval(); } diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h index 72f1f3087b04..de607e4febd9 100644 --- a/kernel/sched/sched.h +++ b/kernel/sched/sched.h @@ -1809,16 +1809,3 @@ static inline void cpufreq_trigger_update(u64 time) {} #else /* arch_scale_freq_capacity */ #define arch_scale_freq_invariant() (false) #endif - -static inline void account_reset_rq(struct rq *rq) -{ -#ifdef CONFIG_IRQ_TIME_ACCOUNTING - rq->prev_irq_time = 0; -#endif -#ifdef CONFIG_PARAVIRT - rq->prev_steal_time = 0; -#endif -#ifdef CONFIG_PARAVIRT_TIME_ACCOUNTING - rq->prev_steal_time_rq = 0; -#endif -} |