From patchwork Mon Aug 21 01:27:31 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yang Jihong X-Patchwork-Id: 136415 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:b82d:0:b0:3f2:4152:657d with SMTP id z13csp3150854vqi; Mon, 21 Aug 2023 10:18:10 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHmrb8dzF3tpChjNY4gsCVaLl5hwSL3vQCJ+pU4ZpZl5BeuqVMD5LXau68FMpVOmVOUku2r X-Received: by 2002:a17:902:f681:b0:1bc:56c3:ebb6 with SMTP id l1-20020a170902f68100b001bc56c3ebb6mr11338384plg.8.1692638289788; Mon, 21 Aug 2023 10:18:09 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1692638289; cv=none; d=google.com; s=arc-20160816; b=j5o7+JJ0gJr458UTzCWmNzabMHjDH/L8Q6NukKEXjfuli3YHKHler3zwf/fSA6iqNL HbQ1vJmQ5Qynmh9ihF6nsZZ2xhIWCA3Ri45L2ik4simfZ1zg0rNQQrRzCMxg0HYY5HPZ XHm2lcsqc79UnvR5sk9dq7NUmwU0FMUEo9vfEshbyGVUSc5VMcLmlpDE/YJvqOwOwo0q SQRdYfDpq/oMesCxlxh1n5VFGxZrk5kjN9ELt9H2OXShQNFBR2jVddxcZunI1MecaK0j eFcyhBzN7LIWgU235CYGm37xPJ6KVIzL/RbIdn//Pf4yvCPtbkzH6XqiUz038UmChtvf Ruwg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :references:in-reply-to:message-id:date:subject:cc:to:from; bh=9+5niE0zVSvITtB+ESQwvuRIrye14zahF4rA4Z9v9Bs=; fh=Ib1wi7jRbo+eNDLEErvWCJx+cnUm87PkGFthhdFf08Y=; b=qH7HnSIQ9YRp1LXxCHOEUMCDceTdVl+xZnpmkhYMND33PGSLfb29SmG/AltJZ/JuEV qKf9LYZ2ce1SDo2ed/zC46SBpSPgg5OBLA/4jK3JQor9f9DAlNG19TCu8O4ClSXLWU4B iFm+7WSxRrVvw123K1t0NcbC2fCyqq8E5Joxbad9IGPsZASAOsiw10tubVva70C4+IzB 3ge8yx1rxO6aSujuivaZ8Lq6tfjPMoR9v/Jz4CnFjhZYdqhpGR91O0cKip2PX9Ly1RvO /QHAgohHLs76uOrHHtJ6SIUKaernk3rCO3YdY6vTNfiQSyrpxIuthMu+aWWmeHDF5A3t saSg== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=huawei.com Received: from out1.vger.email (out1.vger.email. [2620:137:e000::1:20]) by mx.google.com with ESMTP id d11-20020a170903208b00b001b8c4021be9si7270418plc.397.2023.08.21.10.17.55; Mon, 21 Aug 2023 10:18:09 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=huawei.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232446AbjHUBak (ORCPT + 99 others); Sun, 20 Aug 2023 21:30:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40466 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232328AbjHUBae (ORCPT ); Sun, 20 Aug 2023 21:30:34 -0400 Received: from szxga08-in.huawei.com (szxga08-in.huawei.com [45.249.212.255]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C42EA0; Sun, 20 Aug 2023 18:30:31 -0700 (PDT) Received: from kwepemm600003.china.huawei.com (unknown [172.30.72.57]) by szxga08-in.huawei.com (SkyGuard) with ESMTP id 4RTZdC3CWZz1L90b; Mon, 21 Aug 2023 09:29:03 +0800 (CST) Received: from localhost.localdomain (10.67.174.95) by kwepemm600003.china.huawei.com (7.193.23.202) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Mon, 21 Aug 2023 09:30:29 +0800 From: Yang Jihong To: , , , , , , , , , , , , , , , CC: Subject: [PATCH v6 4/7] perf record: Track sideband events for all CPUs when tracing selected CPUs Date: Mon, 21 Aug 2023 01:27:31 +0000 Message-ID: <20230821012734.18241-5-yangjihong1@huawei.com> X-Mailer: git-send-email 2.30.GIT In-Reply-To: <20230821012734.18241-1-yangjihong1@huawei.com> References: <20230821012734.18241-1-yangjihong1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.174.95] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemm600003.china.huawei.com (7.193.23.202) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1774851993853639344 X-GMAIL-MSGID: 1774859887232896991 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_MMAP events of taskA. Therefore, the comm and symbols of taskA cannot be parsed. The solution is to record sideband events for all CPUs when tracing selected CPUs. Because this modifies the default behavior, add related comments to the perf record man page. 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 (PERF_TYPE_SOFTWARE) size 136 config 0 (PERF_COUNT_SW_CPU_CLOCK) { sample_period, sample_freq } 4000 sample_type IP|TID|TIME|CPU|PERIOD|IDENTIFIER 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:u ------------------------------------------------------------ perf_event_attr: type 1 (PERF_TYPE_SOFTWARE) size 136 config 0x9 (PERF_COUNT_SW_DUMMY) { sample_period, sample_freq } 1 sample_type IP|TID|TIME|CPU|IDENTIFIER read_format ID|LOST inherit 1 exclude_kernel 1 exclude_hv 1 mmap 1 comm 1 task 1 sample_id_all 1 exclude_guest 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 Acked-by: Adrian Hunter --- tools/perf/Documentation/perf-record.txt | 3 ++ tools/perf/builtin-record.c | 44 +++++++++++++++++++++++- 2 files changed, 46 insertions(+), 1 deletion(-) diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index d5217be012d7..1889f66addf2 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -374,6 +374,9 @@ comma-separated list with no space: 0,1. Ranges of CPUs are specified with -: 0- In per-thread mode with inheritance mode on (default), samples are captured only when the thread executes on the designated CPUs. Default is to monitor all CPUs. +User space tasks can migrate between CPUs, so when tracing selected CPUs, +a dummy event is created to track sideband for all CPUs. + -B:: --no-buildid:: Do not save the build ids of binaries in the perf.data files. This skips diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 4ee94058028f..ae2e21b945fa 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -906,10 +906,44 @@ static int record__config_off_cpu(struct record *rec) return off_cpu_prepare(rec->evlist, &rec->opts.target, &rec->opts); } +static bool record__tracking_system_wide(struct record *rec) +{ + struct record_opts *opts = &rec->opts; + struct evlist *evlist = rec->evlist; + struct evsel *evsel; + + /* + * If all (non-dummy) evsel have exclude_user, + * system_wide is not needed. + * + * all_kernel and all_user will overwrite exclude_kernel and + * exclude_user of attr in evsel__config(), here need to check + * all the three items. + * + * Sideband system wide if one of the following conditions is met: + * + * - all_user is set, and there is a non-dummy event + * - all_user and all_kernel are not set, and there is + * a non-dummy event without exclude_user + */ + if (opts->all_kernel) + return false; + + evlist__for_each_entry(evlist, evsel) { + if (!evsel__is_dummy_event(evsel)) { + if (opts->all_user || !evsel->core.attr.exclude_user) + return true; + } + } + + return false; +} + static int record__config_tracking_events(struct record *rec) { struct record_opts *opts = &rec->opts; struct evlist *evlist = rec->evlist; + bool system_wide = false; struct evsel *evsel; /* @@ -919,7 +953,15 @@ static int record__config_tracking_events(struct record *rec) */ if (opts->target.initial_delay || target__has_cpu(&opts->target) || perf_pmus__num_core_pmus() > 1) { - evsel = evlist__findnew_tracking_event(evlist, false); + + /* + * User space tasks can migrate between CPUs, so when tracing + * selected CPUs, sideband for all CPUs is still needed. + */ + if (!!opts->target.cpu_list && record__tracking_system_wide(rec)) + system_wide = true; + + evsel = evlist__findnew_tracking_event(evlist, system_wide); if (!evsel) return -ENOMEM;