Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752387AbZLOFvj (ORCPT ); Tue, 15 Dec 2009 00:51:39 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752058AbZLOFvi (ORCPT ); Tue, 15 Dec 2009 00:51:38 -0500 Received: from e3.ny.us.ibm.com ([32.97.182.143]:39405 "EHLO e3.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751853AbZLOFvh (ORCPT ); Tue, 15 Dec 2009 00:51:37 -0500 Date: Mon, 14 Dec 2009 21:51:33 -0800 From: "Paul E. McKenney" To: Arnaldo Carvalho de Melo Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Stephen Hemminger , =?iso-8859-1?Q?Fr=E9d=E9ric?= Weisbecker , Mike Galbraith , Peter Zijlstra , Paul Mackerras Subject: Re: [PATCH 3/3] perf diff: Introduce tool to show performance difference Message-ID: <20091215055133.GA6759@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com References: <1260828571-3613-1-git-send-email-acme@infradead.org> <1260828571-3613-3-git-send-email-acme@infradead.org> <20091214224708.GF6679@linux.vnet.ibm.com> <20091214233026.GC21796@ghostprotocols.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20091214233026.GC21796@ghostprotocols.net> User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3657 Lines: 85 On Mon, Dec 14, 2009 at 09:30:26PM -0200, Arnaldo Carvalho de Melo wrote: > Em Mon, Dec 14, 2009 at 02:47:08PM -0800, Paul E. McKenney escreveu: > > On Mon, Dec 14, 2009 at 08:09:31PM -0200, Arnaldo Carvalho de Melo wrote: > > > From: Arnaldo Carvalho de Melo > > > > > > I guess it is enough to show some examples: > > > > Very cool!!! > > > > Some questions on the numbers below... > > Lets go! [ . . . ] Thank you for the info!!! > in another, and look at what happen when you flip those xterms. > > And if you want to see an html rendering of what I wanted to get coming > accross: > > http://esporte.uol.com.br/futebol/campeonatos/brasileiro/2009/serie-a/classificacao.jhtm Differential profiling applied to soccer statistics... No -there- is a scary thought!!! ;-) Thanx, Paul > > > [root@doppio linux-2.6-tip]# perf diff -p | head -5 > > > 1 +1.00% /lib64/libc-2.10.1.so _IO_vfprintf_internal > > > 2 [kernel.kallsyms] __kmalloc > > > 3 +1 /lib64/libc-2.10.1.so __GI_memmove > > > 4 +4 /lib64/libc-2.10.1.so _int_malloc > > > 5 +7 -1.00% [kernel.kallsyms] __d_lookup > > > > The third column is percent of total execution time? Or percent change > > in profile ticks? My guess is the former. > > counter percentage wrt the total number of hits for that particualr > session. The unit is whatever is specified in --event, i.e. the counter > specified, whichever it is. > > > > [root@doppio linux-2.6-tip]# perf diff -v | head -5 > > > 1 361449551 326454971 -34994580 /lib64/libc-2.10.1.so _IO_vfprintf_internal > > > 2 151009241 135701435 -15307806 [kernel.kallsyms] __kmalloc > > > 3 +1 101805328 105471269 +3665941 /lib64/libc-2.10.1.so __GI_memmove > > > 4 +4 78041440 101550435 +23508995 /lib64/libc-2.10.1.so _int_malloc > > > 5 +7 59536172 98074985 +38538813 [kernel.kallsyms] __d_lookup > > > [root@doppio linux-2.6-tip]# perf diff -vp | head -5 > > > 1 9.00% 8.00% +1.00% /lib64/libc-2.10.1.so _IO_vfprintf_internal > > > 2 3.00% 3.00% [kernel.kallsyms] __kmalloc > > > 3 +1 2.00% 2.00% /lib64/libc-2.10.1.so __GI_memmove > > > 4 +4 2.00% 2.00% /lib64/libc-2.10.1.so _int_malloc > > > 5 +7 1.00% 2.00% -1.00% [kernel.kallsyms] __d_lookup > > > > If these examples are all using the same numbers, then the percentages > > must be of total execution time rather than percent change in the > > profiling ticks? > > Its all using the same perf.data.old + perf.data files, so the numbers > are for the default -e metrics, which is PERF_COUNT_HW_CPU_CYCLES. > > > > [root@doppio linux-2.6-tip]# > > > > > > This should be enough for diffs where the system is non volatile, i.e. when one > > > doesn't updates binaries. > > > > > > For volatile environments, stay tuned for the next perf tool feature: a buildid > > > cache populated by 'perf record', managed by 'perf buildid-cache' a-la ccache, > > > and used by all the report tools. > > > > For scalability studies, it would be very cool to have a ratio as well > > as a difference, but again, good stuff!!! > > Point taken! > > Please let me know about any other issue or suggestion you may come to! > > - 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/