From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752606AbbHQTQ3 (ORCPT ); Mon, 17 Aug 2015 15:16:29 -0400 Received: from casper.infradead.org ([85.118.1.10]:39537 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752151AbbHQTMT (ORCPT ); Mon, 17 Aug 2015 15:12:19 -0400 From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Adrian Hunter , Jiri Olsa , Arnaldo Carvalho de Melo Subject: [PATCH 07/14] perf tools: Add a helper function to probe whether cpu-wide tracing is possible Date: Mon, 17 Aug 2015 16:12:00 -0300 Message-Id: <1439838727-6824-8-git-send-email-acme@kernel.org> X-Mailer: git-send-email 2.1.0 In-Reply-To: <1439838727-6824-1-git-send-email-acme@kernel.org> References: <1439838727-6824-1-git-send-email-acme@kernel.org> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.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: Adrian Hunter Add a helper function to probe whether cpu-wide tracing is possible. Signed-off-by: Adrian Hunter Cc: Jiri Olsa Link: http://lkml.kernel.org/r/1439458857-30636-2-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/evlist.h | 1 + tools/perf/util/record.c | 24 ++++++++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/tools/perf/util/evlist.h b/tools/perf/util/evlist.h index 397757063da1..436e358300b1 100644 --- a/tools/perf/util/evlist.h +++ b/tools/perf/util/evlist.h @@ -115,6 +115,7 @@ void perf_evlist__close(struct perf_evlist *evlist); void perf_evlist__set_id_pos(struct perf_evlist *evlist); bool perf_can_sample_identifier(void); bool perf_can_record_switch_events(void); +bool perf_can_record_cpu_wide(void); void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts); int record_opts__config(struct record_opts *opts); diff --git a/tools/perf/util/record.c b/tools/perf/util/record.c index 0d228a29526d..0467367dc315 100644 --- a/tools/perf/util/record.c +++ b/tools/perf/util/record.c @@ -105,6 +105,30 @@ bool perf_can_record_switch_events(void) return perf_probe_api(perf_probe_context_switch); } +bool perf_can_record_cpu_wide(void) +{ + struct perf_event_attr attr = { + .type = PERF_TYPE_SOFTWARE, + .config = PERF_COUNT_SW_CPU_CLOCK, + .exclude_kernel = 1, + }; + struct cpu_map *cpus; + int cpu, fd; + + cpus = cpu_map__new(NULL); + if (!cpus) + return false; + cpu = cpus->map[0]; + cpu_map__put(cpus); + + fd = sys_perf_event_open(&attr, -1, cpu, -1, 0); + if (fd < 0) + return false; + close(fd); + + return true; +} + void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts) { struct perf_evsel *evsel; -- 2.1.0