From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753990Ab0EIPY3 (ORCPT ); Sun, 9 May 2010 11:24:29 -0400 Received: from casper.infradead.org ([85.118.1.10]:40369 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751885Ab0EIPYV (ORCPT ); Sun, 9 May 2010 11:24:21 -0400 Date: Sun, 9 May 2010 08:23:23 -0700 From: Arjan van de Ven To: Arjan van de Ven Cc: linux-kernel@vger.kernel.org, mingo@elte.hu, davej@redhat.com Subject: [PATCH v2 3/8] sched: Update the idle statistics in get_cpu_idle_time_us() Message-ID: <20100509082323.2d2f1945@infradead.org> In-Reply-To: <20100509082126.4a080d46@infradead.org> References: <20100509082126.4a080d46@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: 7bit 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 From: Arjan van de Ven 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 Signed-off-by: Andrew Morton Reviewed-by: Rik van Riel --- kernel/time/tick-sched.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff -puN kernel/time/tick-sched.c~sched-update-the-idle-statistics-in-get_cpu_idle_time_us kernel/time/tick-sched.c --- a/kernel/time/tick-sched.c~sched-update-the-idle-statistics-in-get_cpu_idle_time_us +++ a/kernel/time/tick-sched.c @@ -161,6 +161,7 @@ static void update_ts_time_stats(struct 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(stru 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); } _