Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753191Ab1EGIUp (ORCPT ); Sat, 7 May 2011 04:20:45 -0400 Received: from mx2.mail.elte.hu ([157.181.151.9]:38643 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752402Ab1EGIUm (ORCPT ); Sat, 7 May 2011 04:20:42 -0400 Date: Sat, 7 May 2011 10:20:18 +0200 From: Ingo Molnar To: Andi Kleen Cc: Thomas Gleixner , Eric Dumazet , john stultz , lkml , Paul Mackerras , "Paul E. McKenney" , Anton Blanchard Subject: Re: [RFC] time: xtime_lock is held too long Message-ID: <20110507082018.GC25065@elte.hu> References: <1304574244.32152.666.camel@edumazet-laptop> <1304576495.2943.40.camel@work-vm> <1304604284.3032.78.camel@edumazet-laptop> <1304608095.3032.95.camel@edumazet-laptop> <20110505210118.GI2925@one.firstfloor.org> <20110506102232.GA11036@elte.hu> <20110506165359.GE11636@one.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20110506165359.GE11636@one.firstfloor.org> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.3.1 -2.0 BAYES_00 BODY: Bayes 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 Content-Length: 783 Lines: 22 * Andi Kleen wrote: > > Then precise measurements have to be done on the source of cache misses, the > > total cost of the timer interrupt, etc. > > What we did was profiling the remote node cache misses > using raw offcore events, and the xtime code was high up. > I cannot share exact numbers for various reasons, but it was > an improvement on a hard to improve workload. You could certainly share the profiling commands you typed, so that others can reproduce and double check your results. Thanks, Ingo -- 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/