From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Ahern Subject: Re: perf top -z not working? Date: Mon, 22 Oct 2012 07:12:19 -0600 Message-ID: <50854633.30206@gmail.com> References: <507EA40D.60206@cs.utoronto.ca> <507EB776.9030304@core.kaist.ac.kr> <20121022014618.GA7924@ghostprotocols.net> <50853311.3040707@cs.utoronto.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail-pa0-f46.google.com ([209.85.220.46]:45819 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753537Ab2JVNMW (ORCPT ); Mon, 22 Oct 2012 09:12:22 -0400 Received: by mail-pa0-f46.google.com with SMTP id hz1so1922221pad.19 for ; Mon, 22 Oct 2012 06:12:22 -0700 (PDT) In-Reply-To: <50853311.3040707@cs.utoronto.ca> Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: Ryan Johnson Cc: Arnaldo Carvalho de Melo , Chulmin Kim , linux-perf-users@vger.kernel.org On 10/22/12 5:50 AM, Ryan Johnson wrote: >>>> It seems that `perf top -z' does not behave as advertized, at >>>> least not on the 3.2.0-25 kernel (Ubuntu) that I'm running. The >>>> man page states that it should "zero history across display >>>> updates" but the counts still seem to accumulate (the total >>>> samples reported rises monotonically) and processes still show up >>>> in the display long after they have exited. Pressing `z' or `Z' >>>> seems to have no effect, either. >> Are you using the --tui or --stdio interface? Try with both and check if >> it works in one of them, I bet the problem is with --tui. > --stdio does the same, so I'll have to try updating my kernel like > Chulmin suggested (haven't had time to do that yet) The kernel has nothing to do with the feature. From builtin-top.c, this part is either not happening or more likely not happening correctly. if (top->zero) symbol__annotate_zero_histogram(symbol, top->sym_evsel->idx); else symbol__annotate_decay_histogram(symbol, top->sym_evsel->idx); I recall it working recently - last year or so. Can you try different versions -- say 3.0, 3.2, 3.4 and latest? If you have a copy of Linus' tree or Arnaldo's git tree it should not take much time. David