From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752174AbaLRG3Z (ORCPT ); Thu, 18 Dec 2014 01:29:25 -0500 Received: from terminus.zytor.com ([198.137.202.10]:58568 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751701AbaLRG3X (ORCPT ); Thu, 18 Dec 2014 01:29:23 -0500 Date: Wed, 17 Dec 2014 22:28:41 -0800 From: tip-bot for Arnaldo Carvalho de Melo Message-ID: Cc: hpa@zytor.com, paulus@samba.org, jolsa@redhat.com, tglx@linutronix.de, peterz@infradead.org, bp@suse.de, mingo@kernel.org, eranian@google.com, dsahern@gmail.com, namhyung@kernel.org, acme@redhat.com, adrian.hunter@intel.com, efault@gmx.de, linux-kernel@vger.kernel.org, dzickus@redhat.com, fweisbec@gmail.com Reply-To: mingo@kernel.org, paulus@samba.org, hpa@zytor.com, jolsa@redhat.com, peterz@infradead.org, bp@suse.de, tglx@linutronix.de, fweisbec@gmail.com, dsahern@gmail.com, eranian@google.com, adrian.hunter@intel.com, acme@redhat.com, namhyung@kernel.org, efault@gmx.de, dzickus@redhat.com, linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/urgent] perf evlist: Improve the strerror_mmap method Git-Commit-ID: e965bea1ad1a8062b306f7fcc5c3e05dc5213b7c 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: e965bea1ad1a8062b306f7fcc5c3e05dc5213b7c Gitweb: http://git.kernel.org/tip/e965bea1ad1a8062b306f7fcc5c3e05dc5213b7c Author: Arnaldo Carvalho de Melo AuthorDate: Fri, 12 Dec 2014 16:25:33 -0300 Committer: Arnaldo Carvalho de Melo CommitDate: Tue, 16 Dec 2014 13:38:26 -0300 perf evlist: Improve the strerror_mmap method Considering the per user locked pages limit, improve the message when a user uses multiple simultaneous perf mmap calls: When the request is more than the current maximum: [acme@ssdandy linux]$ trace -m 128 usleep 1 Error: Operation not permitted. Hint: Check /proc/sys/kernel/perf_event_mlock_kb (516 kB) setting. Hint: Tried using 516 kB. Hint: Try 'sudo sh -c "echo 1032 > /proc/sys/kernel/perf_event_mlock_kb"', or Hint: Try using a smaller -m/--mmap-pages value. [acme@ssdandy linux]$ And when the limit is less than that: [acme@ssdandy linux]$ trace -m 512 usleep 1 Error: Operation not permitted. Hint: Check /proc/sys/kernel/perf_event_mlock_kb (2056 kB) setting. Hint: Tried using 2052 kB. Hint: Try using a smaller -m/--mmap-pages value. [acme@ssdandy linux]$ Cc: Adrian Hunter Cc: Borislav Petkov Cc: David Ahern Cc: Don Zickus Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-yqdie3c8qvdgenwleri267d4@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evlist.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index d661f25..7847f38 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -1487,16 +1487,25 @@ int perf_evlist__strerror_open(struct perf_evlist *evlist __maybe_unused, int perf_evlist__strerror_mmap(struct perf_evlist *evlist, int err, char *buf, size_t size) { char sbuf[STRERR_BUFSIZE], *emsg = strerror_r(err, sbuf, sizeof(sbuf)); - int pages_attempted = evlist->mmap_len / 1024, pages_max_per_user; + int pages_attempted = evlist->mmap_len / 1024, pages_max_per_user, printed = 0; switch (err) { case EPERM: sysctl__read_int("kernel/perf_event_mlock_kb", &pages_max_per_user); - scnprintf(buf, size, "Error:\t%s.\n" + printed += scnprintf(buf + printed, size - printed, + "Error:\t%s.\n" "Hint:\tCheck /proc/sys/kernel/perf_event_mlock_kb (%d kB) setting.\n" - "Hint:\tTried using %zd kB.\n" - "Hint:\tTry using a smaller -m/--mmap-pages value.", + "Hint:\tTried using %zd kB.\n", emsg, pages_max_per_user, pages_attempted); + + if (pages_attempted >= pages_max_per_user) { + printed += scnprintf(buf + printed, size - printed, + "Hint:\tTry 'sudo sh -c \"echo %d > /proc/sys/kernel/perf_event_mlock_kb\"', or\n", + pages_max_per_user + pages_attempted); + } + + printed += scnprintf(buf + printed, size - printed, + "Hint:\tTry using a smaller -m/--mmap-pages value."); break; default: scnprintf(buf, size, "%s", emsg);