[tip:sched/core] sched: Update the idle statistics in get_cpu_idle_time_us()
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From: tip-bot for Arjan van de Ven on 10 May 2010 02:00 Commit-ID: 8c7b09f43f4bf570654bcc458ce96819a932303c Gitweb: http://git.kernel.org/tip/8c7b09f43f4bf570654bcc458ce96819a932303c Author: Arjan van de Ven <arjan(a)linux.intel.com> AuthorDate: Sun, 9 May 2010 08:23:23 -0700 Committer: Ingo Molnar <mingo(a)elte.hu> CommitDate: Sun, 9 May 2010 19:35:26 +0200 sched: Update the idle statistics in get_cpu_idle_time_us() Right now, get_cpu_idle_time_us() only reports the idle statistics upto the point the CPU entered last idle; not what is valid right now. This patch adds an update of the idle statistics to get_cpu_idle_time_us(), so that calling this function always returns statistics that are accurate at the point of the call. This includes resetting the start of the idle time for accounting purposes to avoid double accounting. Signed-off-by: Arjan van de Ven <arjan(a)linux.intel.com> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Reviewed-by: Rik van Riel <riel(a)redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra(a)chello.nl> Cc: davej(a)redhat.com LKML-Reference: <20100509082323.2d2f1945(a)infradead.org> Signed-off-by: Ingo Molnar <mingo(a)elte.hu> --- kernel/time/tick-sched.c | 7 ++++++- 1 files changed, 6 insertions(+), 1 deletions(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 59d8762..f15d18d 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -161,6 +161,7 @@ static void update_ts_time_stats(struct tick_sched *ts, ktime_t now) if (ts->idle_active) { delta = ktime_sub(now, ts->idle_entrytime); ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta); + ts->idle_entrytime = now; } } @@ -205,14 +206,18 @@ static ktime_t tick_nohz_start_idle(struct tick_sched *ts) u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time) { struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); + ktime_t now; if (!tick_nohz_enabled) return -1; + now = ktime_get(); + update_ts_time_stats(ts, now); + if (ts->idle_active) *last_update_time = ktime_to_us(ts->idle_lastupdate); else - *last_update_time = ktime_to_us(ktime_get()); + *last_update_time = ktime_to_us(now); return ktime_to_us(ts->idle_sleeptime); } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |