[PATCH 1/7] sched: add a comment to get_cpu_idle_time_us()
in [Kernel]
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From: Arjan van de Ven on 18 Apr 2010 15:10 From 6f9df3bc6571d6545c552151f408d69265e15f92 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven <arjan(a)linux.intel.com> Date: Sun, 18 Apr 2010 10:25:19 -0700 Subject: [PATCH 1/7] sched: add a comment to get_cpu_idle_time_us() The exported function get_cpu_idle_time_us() has no comment describing it; add a kerneldoc comment Signed-off-by: Arjan van de Ven <arjan(a)linux.intel.com> --- kernel/time/tick-sched.c | 14 ++++++++++++++ 1 files changed, 14 insertions(+), 0 deletions(-) diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index f992762..54dc155 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -179,6 +179,20 @@ static ktime_t tick_nohz_start_idle(struct tick_sched *ts) return now; } +/** + * get_cpu_idle_time_us - get the total idle time of a cpu + * @cpu: CPU number to query + * @last_update_time: variable to store update time in + * + * Return the cummulative idle time (since boot) for a given + * CPU, in microseconds. The idle time returned includes + * the iowait time (unlike what "top" and co report). + * + * This time is measured via accounting rather than sampling, + * and is as accurate as ktime_get() is. + * + * This function returns -1 if NOHZ is not enabled. + */ u64 get_cpu_idle_time_us(int cpu, u64 *last_update_time) { struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu); -- 1.6.2.5 -- 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/
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