From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752211AbcEAHiM (ORCPT ); Sun, 1 May 2016 03:38:12 -0400 Received: from terminus.zytor.com ([198.137.202.10]:40212 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752069AbcEAHiK (ORCPT ); Sun, 1 May 2016 03:38:10 -0400 Date: Sun, 1 May 2016 00:37:41 -0700 From: tip-bot for Arnaldo Carvalho de Melo Message-ID: Cc: hpa@zytor.com, milian.wolff@kdab.com, wangnan0@huawei.com, brendan.d.gregg@gmail.com, acme@redhat.com, namhyung@kernel.org, tglx@linutronix.de, adrian.hunter@intel.com, dsahern@gmail.com, mingo@kernel.org, fweisbec@gmail.com, linux-kernel@vger.kernel.org, jolsa@kernel.org Reply-To: adrian.hunter@intel.com, dsahern@gmail.com, mingo@kernel.org, jolsa@kernel.org, fweisbec@gmail.com, linux-kernel@vger.kernel.org, hpa@zytor.com, milian.wolff@kdab.com, wangnan0@huawei.com, brendan.d.gregg@gmail.com, acme@redhat.com, namhyung@kernel.org, tglx@linutronix.de To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf evsel: Handle ENOMEM for perf_event_max_stack + PERF_SAMPLE_CALLCHAIN Git-Commit-ID: de46d5268c4ec5c5b473c96fbf56ece188a6ba85 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: de46d5268c4ec5c5b473c96fbf56ece188a6ba85 Gitweb: http://git.kernel.org/tip/de46d5268c4ec5c5b473c96fbf56ece188a6ba85 Author: Arnaldo Carvalho de Melo AuthorDate: Wed, 27 Apr 2016 17:51:45 -0300 Committer: Arnaldo Carvalho de Melo CommitDate: Thu, 28 Apr 2016 09:58:58 -0300 perf evsel: Handle ENOMEM for perf_event_max_stack + PERF_SAMPLE_CALLCHAIN When the kernel allows tweaking perf_event_max_stack and the event being setup has PERF_SAMPLE_CALLCHAIN in its perf_event_attr.sample_type, tell the user that tweaking /proc/sys/kernel/perf_event_max_stack may solve the problem. Before: # echo 32000 > /proc/sys/kernel/perf_event_max_stack # perf record -g usleep 1 Error: The sys_perf_event_open() syscall returned with 12 (Cannot allocate memory) for event (cycles:ppp). /bin/dmesg may provide additional information. No CONFIG_PERF_EVENTS=y kernel support configured? # After: # echo 64000 > /proc/sys/kernel/perf_event_max_stack # perf record -g usleep 1 Error: Not enough memory to setup event with callchain. Hint: Try tweaking /proc/sys/kernel/perf_event_max_stack Hint: Current value: 64000 # Suggested-by: David Ahern Cc: Adrian Hunter Cc: Brendan Gregg Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Milian Wolff Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-ebv0orelj1s1ye857vhb82ov@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evsel.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 334364e2..9bed7f4 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2325,6 +2325,14 @@ int perf_evsel__open_strerror(struct perf_evsel *evsel, struct target *target, "Probably the maximum number of open file descriptors has been reached.\n" "Hint: Try again after reducing the number of events.\n" "Hint: Try increasing the limit with 'ulimit -n '"); + case ENOMEM: + if ((evsel->attr.sample_type & PERF_SAMPLE_CALLCHAIN) != 0 && + access("/proc/sys/kernel/perf_event_max_stack", F_OK) == 0) + return scnprintf(msg, size, + "Not enough memory to setup event with callchain.\n" + "Hint: Try tweaking /proc/sys/kernel/perf_event_max_stack\n" + "Hint: Current value: %d", sysctl_perf_event_max_stack); + break; case ENODEV: if (target->cpu_list) return scnprintf(msg, size, "%s",