Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759922AbZJMNh4 (ORCPT ); Tue, 13 Oct 2009 09:37:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758243AbZJMNhz (ORCPT ); Tue, 13 Oct 2009 09:37:55 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:45858 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750831AbZJMNhz (ORCPT ); Tue, 13 Oct 2009 09:37:55 -0400 Date: Tue, 13 Oct 2009 15:37:07 +0200 From: Ingo Molnar To: Mike Galbraith , Arnaldo Carvalho de Melo , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker Cc: LKML , Peter Zijlstra Subject: Re: [patch] perf_counter tools: remove expensive old debug code from perf top Message-ID: <20091013133707.GA21409@elte.hu> References: <1255438640.7173.1.camel@marge.simson.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1255438640.7173.1.camel@marge.simson.net> User-Agent: Mutt/1.5.18 (2008-05-17) 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=3.2.5 -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 Content-Length: 1331 Lines: 36 * Mike Galbraith wrote: > perf_counter tools: remove expensive old debug code from perf top > > Calling gettimeofday() at high frequency is painful for handicapped > boxen. The spot calling gettimeofday() is old unneeded debug code, so > remove it. Thanks! We still seem to have a performance problem. Just running perf top on a 16-way box: Performance counter stats for 'perf top -e cycles -c 3000000': 585.694831 task-clock-msecs # 0.113 CPUs 35163 context-switches # 0.060 M/sec 17 CPU-migrations # 0.000 M/sec 20355 page-faults # 0.035 M/sec 1476952962 cycles # 2521.711 M/sec 730770658 instructions # 0.495 IPC 11489471 cache-references # 19.617 M/sec 2055001 cache-misses # 3.509 M/sec 5.169518576 seconds time elapsed that's 11% of CPU time used on a single CPU - just displaying a measly 16K irqs/sec. Something's not quite right here. 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/