From mboxrd@z Thu Jan 1 00:00:00 1970 From: William Cohen Subject: Re: Issue perf attaching to processes creating many short-live threads Date: Fri, 23 Oct 2015 15:27:04 -0400 Message-ID: <562A8A08.9010101@redhat.com> References: <562A81ED.70900@redhat.com> <562A82F5.8090306@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mx1.redhat.com ([209.132.183.28]:45507 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753108AbbJWT1G (ORCPT ); Fri, 23 Oct 2015 15:27:06 -0400 In-Reply-To: <562A82F5.8090306@gmail.com> Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: David Ahern , "linux-perf-use." Cc: =?UTF-8?B?5aSn5bmz5oCc?= , oprofile-list On 10/23/2015 02:56 PM, David Ahern wrote: > On 10/23/15 12:52 PM, William Cohen wrote: >> Earlier this month Rei Odeira found that the oprofile tool operf would >> have problems attaching and monitoring a process that created many >> very short-lived threads. It looks like the kernel's perf tool also >> has issues when attempting to attach and monitor a process that is >> creating many short-lived threads. > > known a problem. If this is the problem I think it is you will find that strace shows perf stuck walking /proc directory. > > David > Hi David, Is the following thread related to the problem? [PATCH 1/1] perf,tools: add time out to force stop endless mmap processing" http://lkml.iu.edu/hypermail/linux/kernel/1506.1/02251.html Or is there some other thread about the problem? -Will