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=ham 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 5BF5FC433ED for ; Thu, 6 May 2021 10:46:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2630861177 for ; Thu, 6 May 2021 10:46:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234621AbhEFKrC (ORCPT ); Thu, 6 May 2021 06:47:02 -0400 Received: from foss.arm.com ([217.140.110.172]:32832 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234614AbhEFKrA (ORCPT ); Thu, 6 May 2021 06:47:00 -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 67372D6E; Thu, 6 May 2021 03:46:02 -0700 (PDT) Received: from [10.57.83.253] (unknown [10.57.83.253]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 4EF6D3F73B; Thu, 6 May 2021 03:46:00 -0700 (PDT) Subject: Re: [PATCH 2/7] perf cs-etm: Only search timestamp in current sample's queue. To: coresight@lists.linaro.org Cc: al.grant@arm.com, branislav.rankov@arm.com, denik@chromium.org, suzuki.poulose@arm.com, Mike Leach , Leo Yan , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , John Garry , Will Deacon , Mathieu Poirier , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20210212144513.31765-1-james.clark@arm.com> <20210212144513.31765-3-james.clark@arm.com> From: James Clark Message-ID: <69b81af7-8d94-a6fa-b2e3-ca4e8483d5c0@arm.com> Date: Thu, 6 May 2021 13:45:59 +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: <20210212144513.31765-3-james.clark@arm.com> 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 12/02/2021 16:45, James Clark wrote: > Change initial timestamp search to only operate on the queue > related to the current event. In a later change the bounds > of the aux record will also be used to reset the decoder and > the record is only relevant to a single queue. > > This change makes some files that had coresight data > but didn't syntesise any events start working and generating > events. I'm not sure of the reason for that. I'd expect this > change to only affect the ordering of events. I've gotten to the bottom of this mystery of why decoding starts working because of this change. Currently: * _All_ decoding happens on the first AUX record * Decoding depends on binary data (so also depends on MMAP records) * Ordering of AUX records and MMAP records is timing sensitive So there are two scenarios: 1) The perf.data file contains MMAPs followed by AUX records. Everything works 2) The perf.data file contains an AUX record, followed by MMAPS, then further AUX records. Decoding never worked. Per-thread mode (timeless) always worked because we wait for EXIT rather than AUX to start the decode, which is after MMAPS. Per-cpu mode was always at the mercy of the ordering of events. So it's not a regression that this patchset changes the behaviour here and it's doing more of 'the right thing' now. As a separate change I will add a warning to cs_etm__mem_access() when it fails to find the right binary as this is a current sore point. James > > Signed-off-by: James Clark > --- > tools/perf/util/cs-etm.c | 30 ++++++++++++++---------------- > 1 file changed, 14 insertions(+), 16 deletions(-) > > diff --git a/tools/perf/util/cs-etm.c b/tools/perf/util/cs-etm.c > index 27894facae5e..8f8b448632fb 100644 > --- a/tools/perf/util/cs-etm.c > +++ b/tools/perf/util/cs-etm.c > @@ -97,7 +97,7 @@ struct cs_etm_queue { > /* RB tree for quick conversion between traceID and metadata pointers */ > static struct intlist *traceid_list; > > -static int cs_etm__update_queues(struct cs_etm_auxtrace *etm); > +static int cs_etm__update_queues(struct cs_etm_auxtrace *etm, int cpu); > static int cs_etm__process_queues(struct cs_etm_auxtrace *etm); > static int cs_etm__process_timeless_queues(struct cs_etm_auxtrace *etm, > pid_t tid); > @@ -524,7 +524,6 @@ static void cs_etm__dump_event(struct cs_etm_auxtrace *etm, > static int cs_etm__flush_events(struct perf_session *session, > struct perf_tool *tool) > { > - int ret; > struct cs_etm_auxtrace *etm = container_of(session->auxtrace, > struct cs_etm_auxtrace, > auxtrace); > @@ -534,11 +533,6 @@ static int cs_etm__flush_events(struct perf_session *session, > if (!tool->ordered_events) > return -EINVAL; > > - ret = cs_etm__update_queues(etm); > - > - if (ret < 0) > - return ret; > - > if (etm->timeless_decoding) > return cs_etm__process_timeless_queues(etm, -1); > > @@ -851,10 +845,7 @@ static int cs_etm__setup_queue(struct cs_etm_auxtrace *etm, > etmq->queue_nr = queue_nr; > etmq->offset = 0; > > - if (etm->timeless_decoding) > - return 0; > - else > - return cs_etm__search_first_timestamp(etmq); > + return 0; > } > > static int cs_etm__setup_queues(struct cs_etm_auxtrace *etm) > @@ -874,14 +865,20 @@ static int cs_etm__setup_queues(struct cs_etm_auxtrace *etm) > return 0; > } > > -static int cs_etm__update_queues(struct cs_etm_auxtrace *etm) > +static int cs_etm__update_queues(struct cs_etm_auxtrace *etm, int cpu) > { > + int ret; > if (etm->queues.new_data) { > etm->queues.new_data = false; > - return cs_etm__setup_queues(etm); > + ret = cs_etm__setup_queues(etm); > + if (ret) > + return ret; > } > > - return 0; > + if (!etm->timeless_decoding) > + return cs_etm__search_first_timestamp(etm->queues.queue_array[cpu].priv); > + else > + return 0; > } > > static inline > @@ -2358,8 +2355,9 @@ static int cs_etm__process_event(struct perf_session *session, > else > timestamp = 0; > > - if (timestamp || etm->timeless_decoding) { > - err = cs_etm__update_queues(etm); > + if ((timestamp || etm->timeless_decoding) > + && event->header.type == PERF_RECORD_AUX) { > + err = cs_etm__update_queues(etm, sample->cpu); > if (err) > return err; > } >