From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754323AbbDHNs0 (ORCPT ); Wed, 8 Apr 2015 09:48:26 -0400 Received: from mail-ig0-f171.google.com ([209.85.213.171]:32976 "EHLO mail-ig0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751479AbbDHNsZ (ORCPT ); Wed, 8 Apr 2015 09:48:25 -0400 Message-ID: <552531A7.9070605@gmail.com> Date: Wed, 08 Apr 2015 07:48:23 -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: Arnaldo Carvalho de Melo CC: Linux Kernel Mailing List , Don Zickus , Jiri Olsa , Joe Mario , Ingo Molnar Subject: Re: BUG: perf top enters loop synthesizing events for existing threads References: <20150408134251.GC5403@kernel.org> <20150408134545.GD5403@kernel.org> In-Reply-To: <20150408134545.GD5403@kernel.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/8/15 7:45 AM, Arnaldo Carvalho de Melo wrote: >> I also noticed that if I set /proc/sys/kernel/perf_event_paranoid to -1 >> to run it as !root, then the problem "goes away", which I think probably >> is explained by, as !root, not being able to parse some of the /proc >> files for existing threads and thus not triggering the bug, still >> investigating... odd. because this has nothing to do with perf_events; it is just walking /proc and for the ppid adds a strstr and atoi(str). Something else is at play. I'll take a look. David