From mboxrd@z Thu Jan 1 00:00:00 1970 From: M Kelly Subject: Re: =?utf-8?b?c3Bpbl9sb2Nr?= cause ? Date: Wed, 1 Jun 2016 17:43:12 +0000 (UTC) Message-ID: References: <574F15E4.5070008@lexisnexis.com> <4716588.WReR5L1Wkn@milian-kdab2> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Return-path: Received: from plane.gmane.org ([80.91.229.3]:43526 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932138AbcFARng (ORCPT ); Wed, 1 Jun 2016 13:43:36 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1b8AAy-000316-E9 for linux-perf-users@vger.kernel.org; Wed, 01 Jun 2016 19:43:28 +0200 Received: from 209.243.55.99 ([209.243.55.99]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 01 Jun 2016 19:43:28 +0200 Received: from mark.kelly by 209.243.55.99 with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 01 Jun 2016 19:43:28 +0200 Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: linux-perf-users@vger.kernel.org Milian Wolff kdab.com> writes: > > On Wednesday, June 1, 2016 1:05:40 PM CEST Kelly, Mark (RIS-BCT) wrote: > > Hi, > > > > Perf report for our application shows: > > > > 34.27% [kernel] [k] _spin_lock > > 8.19% libjlib.so [.] CLZWExpander::expand(void*) > > 4.62% libjhtree.so [.] CMRUCacheOf > CJHTreeNode> 1.97% [kernel] [k] futex_wait_setup > > 1.51% [kernel] [k] native_write_msr_safe > > 1.34% [kernel] [k] futex_wake > > > > Any suggestion for how to trace where/who is responsible for the spin_lock ? > > For both cases, you should collect backtraces which should allow you to find > culprits. Have you tried: > > perf record --call-graph dwarf > > or similar? > > Cheers > ok, I will try it, thank you. I will have to upgrade perf or move to a newer kernel ? because dwarf does not seem to be supported on my current system. I will report back what it shows once I get it working. thanks, mark