Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753654AbbDXNtw (ORCPT ); Fri, 24 Apr 2015 09:49:52 -0400 Received: from mail-ie0-f180.google.com ([209.85.223.180]:36785 "EHLO mail-ie0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753175AbbDXNtu (ORCPT ); Fri, 24 Apr 2015 09:49:50 -0400 Message-ID: <553A49FC.9010002@gmail.com> Date: Fri, 24 Apr 2015 07:49:48 -0600 From: David Ahern User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Yunlong Song , a.p.zijlstra@chello.nl, paulus@samba.org, mingo@redhat.com, Arnaldo Carvalho de Melo CC: linux-kernel@vger.kernel.org, wangnan0@huawei.com Subject: Re: [Question] How does perf still record the stack of a specified pid even when that process is interrupted and CPU is scheduled to other process References: <553A45CA.8020808@huawei.com> In-Reply-To: <553A45CA.8020808@huawei.com> Content-Type: text/plain; charset=utf-8; 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: 681 Lines: 18 On 4/24/15 7:31 AM, Yunlong Song wrote: > [Profiling Problem] > > Although perf can record the events (with call stack) of a specified pid, e.g. using > "perf record -g iozone -s 262144 -r 64 -i 0 -i 2". But we find iozone is interrupted That command tells perf to *only* collect data for iozone. This command: perf record -g -a -- iozone .... tells perf to collect samples system wide as long as the iozone process is alive. -- 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/