Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760044AbZJMOn5 (ORCPT ); Tue, 13 Oct 2009 10:43:57 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753756AbZJMOn4 (ORCPT ); Tue, 13 Oct 2009 10:43:56 -0400 Received: from mx1.redhat.com ([209.132.183.28]:16595 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752539AbZJMOnz (ORCPT ); Tue, 13 Oct 2009 10:43:55 -0400 Date: Tue, 13 Oct 2009 11:43:12 -0300 From: Arnaldo Carvalho de Melo To: Mike Galbraith Cc: Ingo Molnar , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , LKML , Peter Zijlstra Subject: Re: [patch] perf_counter tools: remove expensive old debug code from perf top Message-ID: <20091013144312.GE21809@ghostprotocols.net> References: <1255438640.7173.1.camel@marge.simson.net> <20091013133707.GA21409@elte.hu> <1255444919.7042.2.camel@marge.simson.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1255444919.7042.2.camel@marge.simson.net> X-Url: http://oops.ghostprotocols.net:81/blog User-Agent: Mutt/1.5.19 (2009-01-05) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1820 Lines: 44 Em Tue, Oct 13, 2009 at 04:41:59PM +0200, Mike Galbraith escreveu: > On Tue, 2009-10-13 at 15:37 +0200, Ingo Molnar wrote: > > * 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. > > I'll try to figure out why after I do some more wakeup preempt testing. > > btw, something broke top annotation (again). Module symbols still > annotate, but vmlinux symbols went south. I'll check this one, and I'm profiling perf top as well. - Arnaldo -- 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/