Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755704AbaAIMMZ (ORCPT ); Thu, 9 Jan 2014 07:12:25 -0500 Received: from mail-gg0-f171.google.com ([209.85.161.171]:33622 "EHLO mail-gg0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753523AbaAIMMO (ORCPT ); Thu, 9 Jan 2014 07:12:14 -0500 Date: Thu, 9 Jan 2014 09:12:06 -0300 From: Arnaldo Carvalho de Melo To: Namhyung Kim Cc: Vince Weaver , linux-kernel@vger.kernel.org, Chad Paradis , Peter Zijlstra , Paul Mackerras , Ingo Molnar Subject: Re: [patch] perf tools: perf list broken on ARM Message-ID: <20140109121206.GA30069@ghostprotocols.net> References: <871u0hd0x4.fsf@sejong.aot.lge.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871u0hd0x4.fsf@sejong.aot.lge.com> X-Url: http://acmel.wordpress.com User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Em Thu, Jan 09, 2014 at 05:17:27PM +0900, Namhyung Kim escreveu: > Hi Vince, > > On Wed, 8 Jan 2014 16:30:17 -0500 (EST), Vince Weaver wrote: > > just checking on the status of this patch. Am I sending it to the wrong > > place? Did it get lost in the post-holiday e-mail purges? > > > > The bug is annoying if you're trying to use perf on ARM systems. > > Right, acme, would you please merge this? I will, but having a patch authored by someone and Acked-by that same person looks weird, so, to clarify, this was written by Vince, acked by you, right? - Arnaldo > Thanks, > Namhyung > > > > > On Mon, 30 Dec 2013, Vince Weaver wrote: > > > >> > >> "perf list" listing of hardware events doesn't work on older ARM devices. > >> The change enabling event detection: > >> > >> commit b41f1cec91c37eeea6fdb15effbfa24ea0a5536b > >> Author: Namhyung Kim > >> Date: Tue Aug 27 11:41:53 2013 +0900 > >> > >> perf list: Skip unsupported events > >> > >> > >> uses the following code in tools/perf/util/parse-events.c: > >> > >> struct perf_event_attr attr = { > >> .type = type, > >> .config = config, > >> .disabled = 1, > >> .exclude_kernel = 1, > >> }; > >> > >> On ARM machines pre-dating the Cortex-A15 this doesn't work, as > >> these machines don't support .exclude_kernel. So starting with 3.12 > >> "perf list" does not report any hardware events at all on older > >> machines (seen on Rasp-Pi, Pandaboard, Beagleboard, etc). > >> > >> This version of the patch makes changes suggested by Namhyung Kim > >> to check for EACCESS and retry (instead of just dropping > >> the exclude_kernel) so we can properly handle machines where > >> /proc/sys/kernel/perf_event_paranoid is set to 2. > >> > >> Reported-by: Chad Paradis > >> Signed-off-by: Vince Weaver > >> Acked-by: Namhyung Kim > >> > >> diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c > >> index 6de6f89..1fa98b9 100644 > >> --- a/tools/perf/util/parse-events.c > >> +++ b/tools/perf/util/parse-events.c > >> @@ -1082,12 +1082,12 @@ int is_valid_tracepoint(const char *event_string) > >> static bool is_event_supported(u8 type, unsigned config) > >> { > >> bool ret = true; > >> + int open_return; > >> struct perf_evsel *evsel; > >> struct perf_event_attr attr = { > >> .type = type, > >> .config = config, > >> .disabled = 1, > >> - .exclude_kernel = 1, > >> }; > >> struct { > >> struct thread_map map; > >> @@ -1099,7 +1099,20 @@ static bool is_event_supported(u8 type, unsigned config) > >> > >> evsel = perf_evsel__new(&attr); > >> if (evsel) { > >> - ret = perf_evsel__open(evsel, NULL, &tmap.map) >= 0; > >> + open_return = perf_evsel__open(evsel, NULL, &tmap.map); > >> + ret = open_return >= 0; > >> + > >> + if (open_return == -EACCES) { > >> + /* > >> + * This happens if the paranoid value > >> + * /proc/sys/kernel/perf_event_paranoid is set to 2 > >> + * Re-run with exclude_kernel set; we don't do that > >> + * by default as some ARM machines do not support it. > >> + * > >> + */ > >> + evsel->attr.exclude_kernel = 1; > >> + ret = perf_evsel__open(evsel, NULL, &tmap.map) >= 0; > >> + } > >> perf_evsel__delete(evsel); > >> } > >> > >> > > > > Vince Weaver > > vincent.weaver@maine.edu > > http://www.eece.maine.edu/~vweaver/ -- 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/