From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23FF7C43461 for ; Wed, 12 May 2021 14:40:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EB771613E9 for ; Wed, 12 May 2021 14:40:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231274AbhELOlJ (ORCPT ); Wed, 12 May 2021 10:41:09 -0400 Received: from foss.arm.com ([217.140.110.172]:40616 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231268AbhELOlH (ORCPT ); Wed, 12 May 2021 10:41:07 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 700561FB; Wed, 12 May 2021 07:39:59 -0700 (PDT) Received: from [10.57.81.122] (unknown [10.57.81.122]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 584EF3F718; Wed, 12 May 2021 07:39:57 -0700 (PDT) Subject: Re: [PATCH v1 2/3] perf arm-spe: Correct sample flags for dummy event To: Leo Yan , Arnaldo Carvalho de Melo , John Garry , Will Deacon , Mathieu Poirier , Peter Zijlstra , Ingo Molnar , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Al Grant References: <20210429150100.282180-1-leo.yan@linaro.org> <20210429150100.282180-3-leo.yan@linaro.org> From: James Clark Message-ID: Date: Wed, 12 May 2021 17:39:56 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210429150100.282180-3-leo.yan@linaro.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 29/04/2021 18:00, Leo Yan wrote: > The dummy event is mainly used for mmap, the TIME sample is only needed > for per-cpu case so that the perf tool can rely on the correct timing > for parsing symbols. And the CPU sample is useless for mmap. > > This patch enables TIME sample for per-cpu mmap and doesn't enable CPU > sample. For later extension (e.g. support multiple AUX events), it sets > the dummy event when the condition "opts->full_auxtrace" is true. > > Signed-off-by: Leo Yan > --- > tools/perf/arch/arm64/util/arm-spe.c | 30 ++++++++++++++++------------ > 1 file changed, 17 insertions(+), 13 deletions(-) > > diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c > index 902e73a64184..f6eec0900604 100644 > --- a/tools/perf/arch/arm64/util/arm-spe.c > +++ b/tools/perf/arch/arm64/util/arm-spe.c > @@ -70,7 +70,6 @@ static int arm_spe_recording_options(struct auxtrace_record *itr, > struct evsel *evsel, *arm_spe_evsel = NULL; > struct perf_cpu_map *cpus = evlist->core.cpus; > bool privileged = perf_event_paranoid_check(-1); > - struct evsel *tracking_evsel; > int err; > > sper->evlist = evlist; > @@ -126,18 +125,23 @@ static int arm_spe_recording_options(struct auxtrace_record *itr, > evsel__set_sample_bit(arm_spe_evsel, CPU); > > /* Add dummy event to keep tracking */ > - err = parse_events(evlist, "dummy:u", NULL); > - if (err) > - return err; > - > - tracking_evsel = evlist__last(evlist); > - evlist__set_tracking_event(evlist, tracking_evsel); > - > - tracking_evsel->core.attr.freq = 0; > - tracking_evsel->core.attr.sample_period = 1; > - evsel__set_sample_bit(tracking_evsel, TIME); > - evsel__set_sample_bit(tracking_evsel, CPU); > - evsel__reset_sample_bit(tracking_evsel, BRANCH_STACK); > + if (opts->full_auxtrace) { > + struct evsel *tracking_evsel; Hi Leo, I know the "if (opts->full_auxtrace)" pattern is copied from other auxtrace files, but I don't think it does anything because there is this at the top of the function: if (!opts->full_auxtrace) return 0; The same applies for other usages of "full_auxtrace" in the same function. They are all always true. I'm also not sure if it's ever defined what full_auxtrace means. James > + > + err = parse_events(evlist, "dummy:u", NULL); > + if (err) > + return err; > + > + tracking_evsel = evlist__last(evlist); > + evlist__set_tracking_event(evlist, tracking_evsel); > + > + tracking_evsel->core.attr.freq = 0; > + tracking_evsel->core.attr.sample_period = 1; > + > + /* In per-cpu case, always need the time of mmap events etc */ > + if (!perf_cpu_map__empty(cpus)) > + evsel__set_sample_bit(tracking_evsel, TIME); > + } > > return 0; > } >