From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754921Ab3BDMdg (ORCPT ); Mon, 4 Feb 2013 07:33:36 -0500 Received: from mx1.redhat.com ([209.132.183.28]:2788 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753814Ab3BDMdd (ORCPT ); Mon, 4 Feb 2013 07:33:33 -0500 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 06/11] perf tools: Fix event ID retrieval for group format read case Date: Mon, 4 Feb 2013 13:33:00 +0100 Message-Id: <1359981185-16819-7-git-send-email-jolsa@redhat.com> In-Reply-To: <1359981185-16819-1-git-send-email-jolsa@redhat.com> References: <1359981185-16819-1-git-send-email-jolsa@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "jolsa@redhat.com" We need to fail the event ID retrieval in case both following conditions are true: - we are on kernel with no PERF_EVENT_IOC_ID support - PERF_FORMAT_GROUP read format is set The PERF_FORMAT_GROUP read format bit is the killer for retrieving event ID out of the read syscall, because we have no guarantee of the event placement within leader kernel sibling list. 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 --- tools/perf/util/evlist.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/tools/perf/util/evlist.c b/tools/perf/util/evlist.c index 5ba5509..8789adf 100644 --- a/tools/perf/util/evlist.c +++ b/tools/perf/util/evlist.c @@ -310,6 +310,15 @@ static int perf_evlist__id_add_fd(struct perf_evlist *evlist, /* Legacy way to get event id.. All hail to old kernels! */ + /* + * This way does not work with group format read, so bail + * out in that case. + */ + if (perf_evlist__read_format(evlist) & PERF_FORMAT_GROUP) { + pr_err("No kernel support for ':S' group modifier\n"); + return -1; + } + if (!(evsel->attr.read_format & PERF_FORMAT_ID) || read(fd, &read_data, sizeof(read_data)) == -1) return -1; -- 1.7.11.7