Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758570Ab1ENSxU (ORCPT ); Sat, 14 May 2011 14:53:20 -0400 Received: from mail-qw0-f46.google.com ([209.85.216.46]:33001 "EHLO mail-qw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753657Ab1ENSxT convert rfc822-to-8bit (ORCPT ); Sat, 14 May 2011 14:53:19 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:from:date :x-google-sender-auth:message-id:subject:to:cc:content-type :content-transfer-encoding; b=XsprwV6fUiRe0S1XsejFA+shI9N1FySLo97jhyZkBrCVwjSKFftnSVAMEw9kOeUqbb j4M0jDAMR38hmYoVcFLX71M1aOUW6N7FgiPRb7XGewS7O7Fi4wCfvACHcIW96G54X7vH pHE1CfMGk/1/TfFBBmKnPLOfTpPf3BMpuLhBw= MIME-Version: 1.0 In-Reply-To: <4DCEC068.3050301@gmail.com> References: <4DCD4FC5.8020608@gmail.com> <20110513154410.GA6373@elte.hu> <4DCDB886.7090909@gmail.com> <4DCEC068.3050301@gmail.com> From: Wim Heirman Date: Sat, 14 May 2011 20:52:57 +0200 X-Google-Sender-Auth: M_A_DSMUBceLjnTob5RmTTx_1C0 Message-ID: Subject: Re: perf-stat per thread results To: David Ahern Cc: Ingo Molnar , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, Peter Zijlstra , Thomas Gleixner , =?ISO-8859-1?Q?Fr=E9d=E9ric_Weisbecker?= , Brice Goglin Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2118 Lines: 50 2011/5/14 David Ahern : > On 05/14/11 06:49, Wim Heirman wrote: >>> Hmm.... my mileage varies using latest kernel >>> (446cc6345d3de6571bdd0840f48aca441488a28d) >>> >>> $ /tmp/build-perf/perf record --stat -fo /tmp/perf.data -p $(pidof rsyslogd) >>> ^C[ perf record: Woken up 1 times to write data ] >>> [ perf record: Captured and wrote 0.007 MB /tmp/perf.data (~308 samples) ] >>> >>> $ /tmp/build-perf/perf report -T -i /tmp/perf.data >>> # Events: 6 ?cycles >>> # >>> # Overhead ? Command ? ? ?Shared Object ? ? ? ? ? ? ? ? ? ? ?Symbol >>> # ........ ?........ ?................. ?.......................... >>> # >>> ? ?97.61% ?rsyslogd ?libc-2.13.so ? ? ? [.] __libc_disable_asynccancel >>> ? ? 2.39% ?rsyslogd ?[kernel.kallsyms] ?[k] native_write_msr_safe >>> >>> >>> # >>> # (For a higher level overview, try: perf report --sort comm,dso) >>> # >>> # PID ?TID >>> >>> >>> ie., I do not get the counter values. Specifying the counter with -e >>> (e.g., -e branch-misses) does not help -- still no counter output. >> >> Is rsyslogd multithreaded? (Or at least, do the non-main threads >> execute any work during your perf-record measurement) If not, then >> what you see is consistent with what I'm getting, i.e. everything but >> the main thread is reported. > > It is multithreaded, but my point is that I do not get counter output at > the end -- the PID/TID table is empty. I do not get counters for single > threaded processes nor for commands run by perf record -- e.g., > /tmp/build-perf/perf record --stat -e instructions -fo /tmp/perf.data -- > sleep 1 My guess was that none of the threads got scheduled while you did your perf-record run (rsyslogd usually isn't exactly very CPU intensive). And the main thread isn't ever reported, at least that's the bug I'm seeing. Can you try with a compute-intensive, multi-threaded program? Wim. -- 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/