From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754074AbcD2PBK (ORCPT ); Fri, 29 Apr 2016 11:01:10 -0400 Received: from merlin.infradead.org ([205.233.59.134]:48343 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753990AbcD2O5z (ORCPT ); Fri, 29 Apr 2016 10:57:55 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Arnaldo Carvalho de Melo , Adrian Hunter , Brendan Gregg , Frederic Weisbecker , Jiri Olsa , Milian Wolff , Namhyung Kim , Wang Nan Subject: [PATCH 03/13] perf evsel: Handle ENOMEM for perf_event_max_stack + PERF_SAMPLE_CALLCHAIN Date: Fri, 29 Apr 2016 11:57:31 -0300 Message-Id: <1461941861-24207-4-git-send-email-acme@kernel.org> X-Mailer: git-send-email 2.5.5 In-Reply-To: <1461941861-24207-1-git-send-email-acme@kernel.org> References: <1461941861-24207-1-git-send-email-acme@kernel.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by merlin.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Arnaldo Carvalho de Melo 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 334364e25bbe..9bed7f4419d8 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", -- 2.5.5