Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757498Ab0DRTCR (ORCPT ); Sun, 18 Apr 2010 15:02:17 -0400 Received: from casper.infradead.org ([85.118.1.10]:44612 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751579Ab0DRTCP convert rfc822-to-8bit (ORCPT ); Sun, 18 Apr 2010 15:02:15 -0400 Date: Sun, 18 Apr 2010 12:00:50 -0700 From: Arjan van de Ven To: linux-kernel@vger.kernel.org Cc: Arjan van de Ven , akpm@linux-foundation.org, mingo@elte.hu, peterz@infradead.org, tglx@linutronix.de, davej@redhat.com, cpufreq@vger.kernel.org Subject: [PATCH 1/7] sched: add a comment to get_cpu_idle_time_us() Message-ID: <20100418120050.562d63a6@infradead.org> In-Reply-To: <20100418115949.7b743898@infradead.org> References: <20100418115949.7b743898@infradead.org> Organization: Intel X-Mailer: Claws Mail 3.7.5 (GTK+ 2.16.6; i586-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 8BIT X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1619 Lines: 46 >From 6f9df3bc6571d6545c552151f408d69265e15f92 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven 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 --- 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@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/