From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753858AbbJIU72 (ORCPT ); Fri, 9 Oct 2015 16:59:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38276 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751093AbbJIU70 (ORCPT ); Fri, 9 Oct 2015 16:59:26 -0400 Date: Fri, 9 Oct 2015 22:59:24 +0200 From: Jiri Olsa To: kan.liang@intel.com Cc: acme@kernel.org, jolsa@kernel.org, ak@linux.intel.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/1] perf,tools: fix core dump caused by per-socket/core system-wide stat Message-ID: <20151009205924.GA19587@krava.landal.opennet> References: <1444388363-35936-1-git-send-email-kan.liang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1444388363-35936-1-git-send-email-kan.liang@intel.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 09, 2015 at 06:59:23AM -0400, kan.liang@intel.com wrote: > From: Kan Liang > > Perf will core dump if --per-socket/core -a are applied for perf stat. > > The root cause is that cpu_map__build_map set refcnt of evlist's cpu_map > to 1. > It should set refcnt for the newly created cpu_map, not evlist's > cpu_map. > > Here is the example: > > perf stat -e cycles --per-socket -a sleep 1 > > Performance counter stats for 'system wide': > > S0 36 30,196,257 cycles > S1 28 15,823,536 cycles > > 1.001126828 seconds time elapsed > > *** Error in `./perf': corrupted double-linked list: 0x00000000021f9090 > *** > ======= Backtrace: ========= > /lib64/libc.so.6[0x3002e7bbe7] > /lib64/libc.so.6[0x3002e7d2b5] > ./perf(perf_evsel__delete+0x28)[0x485bdd] > ./perf[0x4800e8] > ./perf(perf_evlist__delete+0x5e)[0x482cd5] > ./perf(cmd_stat+0xf25)[0x432328] > ./perf[0x4768e0] > ./perf[0x476ad6] > ./perf[0x476b41] > ./perf(main+0x1d0)[0x476db2] > /lib64/libc.so.6(__libc_start_main+0xf5)[0x3002e21b45] > ./perf[0x4202c5] > > Signed-off-by: Kan Liang > --- > tools/perf/util/cpumap.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/perf/util/cpumap.c b/tools/perf/util/cpumap.c > index c51c29f..dfc1f0b 100644 > --- a/tools/perf/util/cpumap.c > +++ b/tools/perf/util/cpumap.c > @@ -284,7 +284,7 @@ static int cpu_map__build_map(struct cpu_map *cpus, struct cpu_map **res, > /* ensure we process id in increasing order */ > qsort(c->map, c->nr, sizeof(int), cmp_ids); > > - atomic_set(&cpus->refcnt, 1); > + atomic_set(&c->refcnt, 1); ouch ;-) Acked-by: Jiri Olsa thanks, jirka