From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754354AbbCXUK1 (ORCPT ); Tue, 24 Mar 2015 16:10:27 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32970 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752612AbbCXUKZ (ORCPT ); Tue, 24 Mar 2015 16:10:25 -0400 Date: Tue, 24 Mar 2015 16:10:20 -0400 From: Don Zickus To: David Ahern Cc: acme@kernel.org, linux-kernel@vger.kernel.org, Jiri Olsa , jmario@redhat.com Subject: Re: [PATCH] perf tool: Fix ppid for synthesized fork events Message-ID: <20150324201020.GH199787@redhat.com> References: <1426786875-18025-1-git-send-email-dsahern@gmail.com> <20150319205648.GC199787@redhat.com> <550B3A66.2030902@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <550B3A66.2030902@gmail.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 On Thu, Mar 19, 2015 at 03:06:46PM -0600, David Ahern wrote: > On 3/19/15 2:56 PM, Don Zickus wrote: > >On Thu, Mar 19, 2015 at 11:41:15AM -0600, David Ahern wrote: > >>>363b785f38 added synthesized fork events and set a thread's parent id > >>>to itself. Since we are already processing/proc//status the ppid > >>>can be determined properly. Make it so. > >Thanks David. My tester, Joe, is currently running other tests and then is > >out until Tuesday. I will try to provide test feedback by Tuesday or > >Wednesday if it can wait. > > ok. thanks for the heads up. Hmm, preliminary tests, show a significant slow down in perf record and perf report. I would be against this patch for now. We will dig into what the problem is. Joe is running a specjbb bench with lots of threads in the background and running: perf mem record -a -e 'cpu/mem-loads,ldlat=50/pp' -e 'cpu/mem-stores/pp' sleep 10 multiple times to get an average. And also perf mem report --stdio to get that timing average too.. He does this with and without the patch. The difference is usually over 50% extra time with the patch for both the record timings and report timings. :-( Cheers, Don