Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756107Ab2JTOgM (ORCPT ); Sat, 20 Oct 2012 10:36:12 -0400 Received: from mx1.redhat.com ([209.132.183.28]:49336 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753655Ab2JTOdm (ORCPT ); Sat, 20 Oct 2012 10:33:42 -0400 From: Jiri Olsa To: linux-kernel@vger.kernel.org Cc: Jiri Olsa , Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar , Paul Mackerras , Corey Ashford , Frederic Weisbecker , Namhyung Kim Subject: [PATCH 02/11] perf: Do not get values from disabled counters in group format read Date: Sat, 20 Oct 2012 16:33:10 +0200 Message-Id: <1350743599-4805-3-git-send-email-jolsa@redhat.com> In-Reply-To: <1350743599-4805-1-git-send-email-jolsa@redhat.com> References: <1350743599-4805-1-git-send-email-jolsa@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1872 Lines: 60 It's possible some of the counters in the group could be disabled when sampling member of the event group is reading the rest via PERF_SAMPLE_READ sample type processing. Disabled counters could then produce wrong numbers. Fixing that by reading only enabled counters for PERF_SAMPLE_READ sample type processing. Signed-off-by: Jiri Olsa Cc: Arnaldo Carvalho de Melo Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Paul Mackerras Cc: Corey Ashford Cc: Frederic Weisbecker Cc: Namhyung Kim --- kernel/events/core.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 32aec40..5220d01 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4012,12 +4012,24 @@ static void perf_output_read_group(struct perf_output_handle *handle, __output_copy(handle, values, n * sizeof(u64)); list_for_each_entry(sub, &leader->sibling_list, group_entry) { + u64 value = 0; n = 0; - if (sub != event) - sub->pmu->read(sub); + /* + * We are NOT interested in disabled counters, + * giving us strange values and keeping us from + * good night sleep!!! + */ + if (sub->state > PERF_EVENT_STATE_OFF) { + + if (sub != event) + sub->pmu->read(sub); + + value = perf_event_count(sub); + } + + values[n++] = value; - values[n++] = perf_event_count(sub); if (read_format & PERF_FORMAT_ID) values[n++] = primary_event_id(sub); -- 1.7.11.4 -- 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/