Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751793Ab3IQFy1 (ORCPT ); Tue, 17 Sep 2013 01:54:27 -0400 Received: from lgeamrelo01.lge.com ([156.147.1.125]:64279 "EHLO LGEAMRELO01.lge.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751275Ab3IQFyY (ORCPT ); Tue, 17 Sep 2013 01:54:24 -0400 X-AuditID: 9c93017d-b7c9eae0000024ac-51-5237ee8e59d9 From: Namhyung Kim To: Ingo Molnar Cc: Frederic Weisbecker , LKML , Jiri Olsa , David Ahern , Ingo Molnar , Peter Zijlstra , Arnaldo Carvalho de Melo , Stephane Eranian , Linus Torvalds Subject: Re: [PATCH 0/4] perf tools: New comm infrastructure References: <1379017783-27032-1-git-send-email-fweisbec@gmail.com> <20130912203658.GA3216@gmail.com> <20130913124354.GB4844@somewhere> <20130914061148.GF364@gmail.com> Date: Tue, 17 Sep 2013 14:54:22 +0900 In-Reply-To: <20130914061148.GF364@gmail.com> (Ingo Molnar's message of "Sat, 14 Sep 2013 08:11:49 +0200") Message-ID: <87li2wq9gx.fsf@sejong.aot.lge.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2308 Lines: 63 Hi Ingo, On Sat, 14 Sep 2013 08:11:49 +0200, Ingo Molnar wrote: > * Frederic Weisbecker wrote: >> My patches and Namhyung's should improve the comm situation a lot but we >> can't do much miracle. The only way would be perhaps to be able to limit >> the deepness of the callchain branches. >> >> Now may be we can find other big contention point in perf. It's possible >> we also have some endless loop somewhere. > > Well, it was the 100,000+ step linear list walk that was causing 90% of > the slowness here. Namhyung's patch should dramatically improve that. I > guess time for someone to post a combined tree so that it can be tested > all together? I pushed combined tree to 'perf/callchain-v2' branch in my tree git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git Please note that I also pushed other versions (v[1-3]). The v1 is my previous rbtree conversion patch, v2 adds Frederic's new comm infrastructure series on top and v3 adds my revised patch to refer current comm [1] on top of v2. I did my own test again among them. Test data is 400MB perf.data file created by parallel kernel build. $ ls -lh perf.data.big -rw-------. 1 namhyung namhyung 400M Sep 9 10:21 perf.data.big For more precise result, I changed cpufreq governor to 'performance' # echo performance > /sys/devices/system/cpu/cpu3/cpufreq/scaling_governor and run perf report on the cpu. $ taskset -c 3 time -p perf --no-pager report --stdio -i perf.data.big > /dev/null I ran it multiple times for each case and the results did not vary much. baseline v1 v2 v3 ---------------------------------------------------------- real 380.17 12.63 10.02 9.03 user 378.86 11.95 9.66 8.69 sys 0.70 0.65 0.33 0.34 I also tried to cache latest result and reuse it when adding a callchain (in callchain_append() function) but it only hits ~5% and did not help the performance. Thanks, Namhyung [1] https://lkml.org/lkml/2013/9/16/565 -- 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/