Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753580Ab2BVQEb (ORCPT ); Wed, 22 Feb 2012 11:04:31 -0500 Received: from terminus.zytor.com ([198.137.202.10]:50954 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752917Ab2BVQE3 (ORCPT ); Wed, 22 Feb 2012 11:04:29 -0500 Date: Wed, 22 Feb 2012 08:03:19 -0800 From: tip-bot for Stephane Eranian Message-ID: Cc: acme@redhat.com, linux-kernel@vger.kernel.org, eranian@google.com, hpa@zytor.com, mingo@redhat.com, eric.dumazet@gmail.com, peterz@infradead.org, dsahern@gmail.com, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, eranian@google.com, linux-kernel@vger.kernel.org, acme@redhat.com, eric.dumazet@gmail.com, peterz@infradead.org, dsahern@gmail.com, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <20120221145424.GA6757@quad> References: <20120221145424.GA6757@quad> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf tools: fix broken perf record -a mode Git-Commit-ID: 6b1bee9035d430c4b4f586df6df4b3f840e89b5b 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 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.2.6 (terminus.zytor.com [127.0.0.1]); Wed, 22 Feb 2012 08:03:40 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2590 Lines: 68 Commit-ID: 6b1bee9035d430c4b4f586df6df4b3f840e89b5b Gitweb: http://git.kernel.org/tip/6b1bee9035d430c4b4f586df6df4b3f840e89b5b Author: Stephane Eranian AuthorDate: Tue, 21 Feb 2012 15:54:25 +0100 Committer: Arnaldo Carvalho de Melo CommitDate: Tue, 21 Feb 2012 15:05:43 -0200 perf tools: fix broken perf record -a mode The following commit: b52956c perf tools: Allow multiple threads or processes in record, stat, top introduced a bug in the thread_map code which caused perf record -a to not setup system-wide monitoring properly. $ taskset -c 1 noploop 1000 & $ perf record -a -C 1 sleep 10 $ perf report -D | tail -20 cycles stats: TOTAL events: 4413 MMAP events: 4025 COMM events: 340 SAMPLE events: 48 Here I was expecting about 10,000 samples and not 48. In system-wide mode, the PID passed to perf_event_open() must be -1 and it was 0. That caused the kernel to setup a per-process event on PID:0. Consequently, the number of samples captured does not correspond to the requested measurement. The following one-liner fixes the problem for me with or without -C. I would also suggest to change the malloc() to something that matches the struct definition. thread_map->map[] is declared as int map[] and not pid_t map[]. If map[] can only contain pids, then change the struct definition. Acked-by: David Ahern Cc: David Ahern Cc: Eric Dumazet Cc: Ingo Molnar Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20120221145424.GA6757@quad Signed-off-by: Stephane Eranian Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/thread_map.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/tools/perf/util/thread_map.c b/tools/perf/util/thread_map.c index e15983c..84d9bd78 100644 --- a/tools/perf/util/thread_map.c +++ b/tools/perf/util/thread_map.c @@ -229,7 +229,7 @@ static struct thread_map *thread_map__new_by_tid_str(const char *tid_str) if (!tid_str) { threads = malloc(sizeof(*threads) + sizeof(pid_t)); if (threads != NULL) { - threads->map[1] = -1; + threads->map[0] = -1; threads->nr = 1; } return threads; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/