Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754113Ab1BYCkW (ORCPT ); Thu, 24 Feb 2011 21:40:22 -0500 Received: from mail-qy0-f181.google.com ([209.85.216.181]:35168 "EHLO mail-qy0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752854Ab1BYCkV (ORCPT ); Thu, 24 Feb 2011 21:40:21 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:x-url:user-agent; b=M03A/L22/Jinf/l49ISybB0q2Q/bZvZmlh0PYpmIlwlR/vUUt64Av0YRdj9aw8qa3n cB667r9aJdfEErRH7LDcZAITJduwZibaCCuWZNdAiX5UcqqvIt/B82d8syoaYllvlZPY +b0WZ8DkS3OutCgJAFE56i3A2IBc8GjtGll90= Date: Thu, 24 Feb 2011 23:40:14 -0300 From: Arnaldo Carvalho de Melo To: Cliff Wickman Cc: linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, paulus@samba.org, mingo@elte.hu Subject: Re: [RFC] Performance Events 'Samples' report Message-ID: <20110225024014.GA16138@ghostprotocols.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3913 Lines: 92 Em Thu, Feb 24, 2011 at 06:15:26PM -0600, Cliff Wickman escreveu: > From: Cliff Wickman > > The perf command's report prints clock periods under the heading of 'Samples'. > Our applications people have been confused by this "Samples" heading. > > perf report -n > > # Overhead Samples Command Shared Object Symbol > # ........ .......... ............... .................... ................................ > # > 99.41%1522136216246 pthreads pthreads [.] work_function > 0.33% 4980298302 perf [kernel.kallsyms] [k] clear_page_c > .... > > It would be more compact to print the number of samples. And that would > be consistent with the heading. > > Below is the code that displays the periods. I don't see that the number > of samples is available here, but probably easily could be. > I presume that clock periods are derived from #samples * sample period. > > perf/util/hist.c > > 640 > 641 if (symbol_conf.show_nr_samples) { > 642 if (sep) > 643 ret += snprintf(s + ret, size - ret, "%c%" PRIu64, *sep, period); > 644 else > 645 ret += snprintf(s + ret, size - ret, "%11" PRIu64, period); > 646 } > 647 Wasn't this fixed by: commit fec9cbd15b9e99bab9bc50f1ed7e20a1087d7c6d Author: Arnaldo Carvalho de Melo Date: Thu Feb 17 10:37:23 2011 -0200 perf hists: Print number of samples, not the period sum So that we match the header where we state the number of events with the "Samples" column when using 'perf report -n/--show-nr-samples': [root@emilia ~]# perf record -a sleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.111 MB perf.data (~4860 samples) ] [root@emilia ~]# perf report --stdio --show-nr-samples # Events: 11 cycles # # Overhead Samples Command Shared Object Symbol # ........ .......... ........... .................. ............................ # 16.65% 1 sleep [kernel.kallsyms] [k] unmap_vmas 16.10% 1 perf libpthread-2.12.so [.] __pthread_cleanup_push_defer 15.79% 2 perf [kernel.kallsyms] [k] format_decode 12.88% 1 kworker/1:2 [kernel.kallsyms] [k] cache_reap 10.69% 1 swapper [kernel.kallsyms] [k] _raw_spin_lock 7.55% 1 sleep [kernel.kallsyms] [k] prepare_exec_creds 6.00% 1 perf [jbd2] [k] start_this_handle 5.29% 1 perf [kernel.kallsyms] [k] seq_read 4.75% 1 perf [kernel.kallsyms] [k] get_pid_task 4.30% 1 perf [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore # # (For a higher level overview, try: perf report --sort comm,dso) # [root@emilia ~]# Reported-by: Stephane Eranian Acked-by: Stephane Eranian Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Mike Galbraith Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Tom Zanussi LKML-Reference: Signed-off-by: Arnaldo Carvalho de Melo ? Please try using tip/perf/core. - 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/