From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758950AbZBMMFj (ORCPT ); Fri, 13 Feb 2009 07:05:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753291AbZBMMFF (ORCPT ); Fri, 13 Feb 2009 07:05:05 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:53830 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753178AbZBMMFE (ORCPT ); Fri, 13 Feb 2009 07:05:04 -0500 Date: Fri, 13 Feb 2009 13:04:30 +0100 From: Ingo Molnar To: Peter Zijlstra Cc: Linus Torvalds , Thomas Gleixner , L-K , Oleg Nesterov Subject: Re: [PATCH] timers: more consistently use clock vs timer Message-ID: <20090213120430.GA5483@elte.hu> References: <1234448191.10603.9.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1234448191.10603.9.camel@laptop> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Peter Zijlstra wrote: > Subject: timers: more consistently use clock vs timer > From: Peter Zijlstra > Date: Thu Feb 12 15:00:52 CET 2009 > > While reviewing the manpages, I noticed I'd missed some clock vs timer sites. > > Make sure that all timer functions call cpu_timer_sample_group() and not > cpu_clock_sample_group(). This ensures that we enable the process wide timer > in time, and therefore pay the O(n) thread group cost from the syscall. > > Not doing it here, will result in the first jiffy tick after setting the timer > doing this, resulting in a very expensive tick (but only once) and a delay in > actually starting the timer. > > Signed-off-by: Peter Zijlstra > --- > kernel/posix-cpu-timers.c | 60 +++++++++++++++++++++++----------------------- > 1 file changed, 30 insertions(+), 30 deletions(-) Applied to tip:timers/urgent, thanks Peter! Ingo