Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753462Ab3JUOvk (ORCPT ); Mon, 21 Oct 2013 10:51:40 -0400 Received: from g6t0184.atlanta.hp.com ([15.193.32.61]:2226 "EHLO g6t0184.atlanta.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752954Ab3JUOvj (ORCPT ); Mon, 21 Oct 2013 10:51:39 -0400 Message-ID: <52653F6E.2030306@hp.com> Date: Mon, 21 Oct 2013 10:51:26 -0400 From: Waiman Long User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:10.0.12) Gecko/20130109 Thunderbird/10.0.12 MIME-Version: 1.0 To: Arnaldo Carvalho de Melo CC: Ingo Molnar , Peter Zijlstra , Paul Mackerras , Namhyung Kim , Jiri Olsa , Adrian Hunter , David Ahern , Stephane Eranian , linux-kernel@vger.kernel.org, Aswin Chandramouleeswaran , Scott J Norton Subject: Re: [PATCH v2 3/4] perf-report: add --max-stack option to limit callchain stack scan References: <1382107129-2010-1-git-send-email-Waiman.Long@hp.com> <1382107129-2010-4-git-send-email-Waiman.Long@hp.com> <20131018171726.GD12054@ghostprotocols.net> In-Reply-To: <20131018171726.GD12054@ghostprotocols.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1569 Lines: 37 On 10/18/2013 01:17 PM, Arnaldo Carvalho de Melo wrote: > Em Fri, Oct 18, 2013 at 10:38:48AM -0400, Waiman Long escreveu: >> When callgraph data was included in the perf data file, it may take a >> long time to scan all those data and merge them together especially >> if the stored callchains are long and the perf data file itself is >> large, like a Gbyte or so. >> >> The callchain stack is currently limited to PERF_MAX_STACK_DEPTH (127). >> This is a large value. Usually the callgraph data that developers are >> most interested in are the first few levels, the rests are usually >> not looked at. >> >> This patch adds a new --max-stack option to perf-report to limit the >> depth of callchain stack data to look at to reduce the time it takes >> for perf-report to finish its processing. It trades the presence of >> trailing stack information with faster speed. >> >> The following table shows the elapsed time of doing perf-report on a >> perf.data file of size 985,531,828 bytes. >> >> --max_stack Elapsed Time Output data size >> ----------- ------------ ---------------- > Please prefix lines like this (------) with a space, otherwise 'git am' > will chop off everything from that line onwards. Fixing it up now. > > - Arnaldo > > Thank for spotting the problem, will fix that in the next version. -Longman -- 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/