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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E4F0FC001DC for ; Tue, 11 Jul 2023 13:13:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232184AbjGKNNp (ORCPT ); Tue, 11 Jul 2023 09:13:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41420 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231226AbjGKNNm (ORCPT ); Tue, 11 Jul 2023 09:13:42 -0400 Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B3979E55; Tue, 11 Jul 2023 06:13:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689081213; x=1720617213; h=message-id:date:mime-version:subject:to:references:from: in-reply-to:content-transfer-encoding; bh=j/p/nhIRZ9ZpkuLx/tRzZlO+OaCeIIAB7XnwRxGyg1w=; b=oFsRI2oOOeUHp6c6QQol62UsaFCBVL6uyfgaH9tzPu5VnNyLk8+S2wPN lfC9UDqQDpCsjcCBX3rpnJueXuGuvyq6sL2aZkq61pqI16HNpKH+TonkL xrdTBbTaMbqZ0xk/thJcj8q6qiV0OBK7SbB4xtFRSS6Ei4f+conG8NxDq MncPVjLrRaj2CLJwWrvTOdnSX8PUaKKMi5SovdJ7kIRPZsgNTOsLLzBNk XSSGKnSRVRaPFhhlHGbrRbqR/4XjEjMKJopW4yZE5a6zgxsYxln2x9LLc UNm1z87XbbnPyj0JyXqho2CL2BoVZUfL6fUN++3JqkJa6L10jMzMhvQl+ g==; X-IronPort-AV: E=McAfee;i="6600,9927,10768"; a="362077029" X-IronPort-AV: E=Sophos;i="6.01,196,1684825200"; d="scan'208";a="362077029" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jul 2023 06:13:33 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10768"; a="786620609" X-IronPort-AV: E=Sophos;i="6.01,196,1684825200"; d="scan'208";a="786620609" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO [10.0.2.15]) ([10.252.44.50]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 11 Jul 2023 06:13:30 -0700 Message-ID: <206972a3-d44d-1c75-3fbc-426427614543@intel.com> Date: Tue, 11 Jul 2023 16:13:26 +0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.13.0 Subject: Re: [PATCH 3/5] perf record: Tracking side-band events for all CPUs when tracing selected CPUs Content-Language: en-US To: Yang Jihong , peterz@infradead.org, mingo@redhat.com, acme@kernel.org, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, namhyung@kernel.org, irogers@google.com, kan.liang@linux.intel.com, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org References: <20230704074217.240939-1-yangjihong1@huawei.com> <20230704074217.240939-4-yangjihong1@huawei.com> From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki In-Reply-To: <20230704074217.240939-4-yangjihong1@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/07/23 10:42, Yang Jihong wrote: > User space tasks can migrate between CPUs, we need to track side-band > events for all CPUs. > > The specific scenarios are as follows: > > CPU0 CPU1 > perf record -C 0 start > taskA starts to be created and executed > -> PERF_RECORD_COMM and PERF_RECORD_MMAP > events only deliver to CPU1 > ...... > | > migrate to CPU0 > | > Running on CPU0 <----------/ > ... > > perf record -C 0 stop > > Now perf samples the PC of taskA. However, perf does not record the > PERF_RECORD_COMM and PERF_RECORD_COMM events of taskA. > Therefore, the comm and symbols of taskA cannot be parsed. > > The sys_perf_event_open invoked is as follows: > > # perf --debug verbose=3 record -e cpu-clock -C 1 true > > Opening: cpu-clock > ------------------------------------------------------------ > perf_event_attr: > type 1 > size 136 > { sample_period, sample_freq } 4000 > sample_type IP|TID|TIME|ID|CPU|PERIOD > read_format ID|LOST > disabled 1 > inherit 1 > freq 1 > sample_id_all 1 > exclude_guest 1 > ------------------------------------------------------------ > sys_perf_event_open: pid -1 cpu 1 group_fd -1 flags 0x8 = 5 > Opening: dummy:HG > ------------------------------------------------------------ > perf_event_attr: > type 1 > size 136 > config 0x9 > { sample_period, sample_freq } 4000 > sample_type IP|TID|TIME|ID|CPU|PERIOD > read_format ID|LOST > inherit 1 > mmap 1 > comm 1 > freq 1 > task 1 > sample_id_all 1 > mmap2 1 > comm_exec 1 > ksymbol 1 > bpf_event 1 > ------------------------------------------------------------ > sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 6 > sys_perf_event_open: pid -1 cpu 1 group_fd -1 flags 0x8 = 7 > sys_perf_event_open: pid -1 cpu 2 group_fd -1 flags 0x8 = 9 > sys_perf_event_open: pid -1 cpu 3 group_fd -1 flags 0x8 = 10 > sys_perf_event_open: pid -1 cpu 4 group_fd -1 flags 0x8 = 11 > sys_perf_event_open: pid -1 cpu 5 group_fd -1 flags 0x8 = 12 > sys_perf_event_open: pid -1 cpu 6 group_fd -1 flags 0x8 = 13 > sys_perf_event_open: pid -1 cpu 7 group_fd -1 flags 0x8 = 14 > > > Signed-off-by: Yang Jihong > --- > tools/perf/builtin-record.c | 31 +++++++++++++++++++++++++++++++ > 1 file changed, 31 insertions(+) > > diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c > index 8872cd037f2c..69e0d8c75aab 100644 > --- a/tools/perf/builtin-record.c > +++ b/tools/perf/builtin-record.c > @@ -908,6 +908,31 @@ static int record__config_off_cpu(struct record *rec) > return off_cpu_prepare(rec->evlist, &rec->opts.target, &rec->opts); > } > > +static int record__config_tracking_events(struct record *rec) > +{ > + struct evsel *evsel; > + struct evlist *evlist = rec->evlist; > + struct record_opts *opts = &rec->opts; > + > + /* > + * User space tasks can migrate between CPUs, so when tracing > + * selected CPUs, sideband for all CPUs is still needed. > + */ > + if (opts->target.cpu_list) { I am not sure if anyone minds doing this by default, but perhaps we should say something about it on the perf record man page. > + evsel = evlist__findnew_tracking_event(evlist); > + if (!evsel) > + return -ENOMEM; > + > + if (!evsel->core.system_wide) { > + evsel->core.system_wide = true; > + evsel__set_sample_bit(evsel, TIME); > + perf_evlist__propagate_maps(&evlist->core, &evsel->core); > + } Perhaps better to export via internel/evsel.h void perf_evsel__go_system_wide(struct perf_evlist *evlist, struct perf_evsel *evsel) { if (!evsel->system_wide) { evsel->system_wide = true; if (evlist->needs_map_propagation) __perf_evlist__propagate_maps(evlist, evsel); } } As suggested in response to patch 2, perhaps deal with system_wide inside evlist__findnew_tracking_event() > + } > + > + return 0; > +} > + > static bool record__kcore_readable(struct machine *machine) > { > char kcore[PATH_MAX]; > @@ -4235,6 +4260,12 @@ int cmd_record(int argc, const char **argv) > goto out; > } > > + err = record__config_tracking_events(rec); > + if (err) { > + pr_err("record__config_tracking_events failed, error %d\n", err); > + goto out; > + } > + > err = record__init_thread_masks(rec); > if (err) { > pr_err("Failed to initialize parallel data streaming masks\n");