From: Sai Gurrappadi <[email protected]> NOHZ related per-cpu data is cleared on CPU down. This was introduced by 4b0c0f294 "tick: Cleanup NOHZ per cpu data on cpu down" which breaks /proc/stats because the idle and iowait sums are now non-monotonic across a CPU down/up cycle.
Fix this by not clearing the idle_sleeptime and iowait_sleeptime fields on CPU down. Signed-off-by: Sai Gurrappadi <[email protected]> Signed-off-by: Peter De Schrijver <[email protected]> --- kernel/time/tick-sched.c | 13 ++++++++++++- 1 files changed, 12 insertions(+), 1 deletions(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index c12c006..2cd27ec 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -1164,6 +1164,17 @@ void tick_setup_sched_timer(void) #endif /* HIGH_RES_TIMERS */ #if defined CONFIG_NO_HZ_COMMON || defined CONFIG_HIGH_RES_TIMERS + +static inline void clear_tick_sched(struct tick_sched *ts) +{ + ktime_t idle_sleeptime = ts->idle_sleeptime; + ktime_t iowait_sleeptime = ts->iowait_sleeptime; + + memset(ts, 0, sizeof(*ts)); + ts->idle_sleeptime = idle_sleeptime; + ts->iowait_sleeptime = iowait_sleeptime; +} + void tick_cancel_sched_timer(int cpu) { struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); @@ -1173,7 +1184,7 @@ void tick_cancel_sched_timer(int cpu) hrtimer_cancel(&ts->sched_timer); # endif - memset(ts, 0, sizeof(*ts)); + clear_tick_sched(ts); } #endif -- 1.7.7.rc0.72.g4b5ea.dirty -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
