From patchwork Sat Jul 22 09:32:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yang Jihong X-Patchwork-Id: 124263 Return-Path: Delivered-To: ouuuleilei@gmail.com Received: by 2002:a59:9010:0:b0:3e4:2afc:c1 with SMTP id l16csp727523vqg; Sat, 22 Jul 2023 03:28:52 -0700 (PDT) X-Google-Smtp-Source: APBJJlEYo6f90SHExzP2/wOWkysKPd0egP75oEfyNnK/tHlyhkpfF0bjB0dNERO+gz40KruQyrLw X-Received: by 2002:a17:902:7893:b0:1b9:d961:69b7 with SMTP id q19-20020a170902789300b001b9d96169b7mr4350254pll.10.1690021731935; Sat, 22 Jul 2023 03:28:51 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1690021731; cv=none; d=google.com; s=arc-20160816; b=yRvl5mMVOCIV6wJ8C98XdoIPUsy3mLth1Rnk00ECTFZV5jvAkiL3N8Ucde0Pcs9qz1 GNkO31N7fIXMcZpmnJ6TAbfbCatvIvJRlJ8Hb23PmsNFrnOfKFqODhU7Kr0n4dCEUE8L 3L7diX7FG++ncakaEq/4qtYrBU6aJbrp8SDLlb3ApycKAsLlQ6TZfP3JIcBqk28ezzL1 hEOP9rLkPOfuAD4QJdUGFCdgZJ+7HthQO0iIwTJfaTMsEslkWMnmsDHkvQFLF0rT98nm bC7axpm5kHNUrw/Wa1g8eLWONQ2e9wNcfPLj1e9un3E3SSrq2F+r846RDdHhBjL7/ZoI VqiQ== 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=5ZnIEtk84GprAgAni+9Xy3W6UwXfLZPX8UXOtpQ94Hg=; fh=Ib1wi7jRbo+eNDLEErvWCJx+cnUm87PkGFthhdFf08Y=; b=vrvijrZUOATHj247ziyUYx/uEB3IRbQpm9lIRw3q39nMLO0JM5oHiekZy7REzDLrth kXQSg5H12e9Dd+uHRLCfGMi3QCsQ0MyOKQ8bL88clfW9pil/yOKEbYKOD6nkGXgSufWp VNequfYlbBJPvOl+6B+YCo+vcIIbjki/0IDyWRHXF2/EgEN5r98YF9nXkLFUoNSExVGr oHYh9W8Jo58FHp+Lk3PWW4nTf0MhSA+IAmRDJUZW6YYh6OqqFJUhSFFk8pp9AbBK3vcj 0ba1QH/enUzBqA59NS4NQzHJvrH6Z4/vPrZDXp8254ldL/qxJoToDOeyQnvNNxuTWeXM 9dgw== 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 ks3-20020a170903084300b001b8b4330585si4609645plb.510.2023.07.22.03.28.38; Sat, 22 Jul 2023 03:28:51 -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 S230049AbjGVJfP (ORCPT + 99 others); Sat, 22 Jul 2023 05:35:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56364 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229805AbjGVJes (ORCPT ); Sat, 22 Jul 2023 05:34:48 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B38F430EF; Sat, 22 Jul 2023 02:34:46 -0700 (PDT) Received: from kwepemm600003.china.huawei.com (unknown [172.30.72.55]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4R7LpW34g8zrRjF; Sat, 22 Jul 2023 17:33:55 +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 15.1.2507.27; Sat, 22 Jul 2023 17:34:43 +0800 From: Yang Jihong To: , , , , , , , , , , , , , , , CC: Subject: [PATCH v3 4/7] perf record: Track sideband events for all CPUs when tracing selected CPUs Date: Sat, 22 Jul 2023 09:32:16 +0000 Message-ID: <20230722093219.174898-5-yangjihong1@huawei.com> X-Mailer: git-send-email 2.30.GIT In-Reply-To: <20230722093219.174898-1-yangjihong1@huawei.com> References: <20230722093219.174898-1-yangjihong1@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.67.174.95] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) 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,RCVD_IN_MSPIKE_H5,RCVD_IN_MSPIKE_WL, SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED 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: 1772115935790334986 X-GMAIL-MSGID: 1772116227825447354 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 --- tools/perf/Documentation/perf-record.txt | 3 +++ tools/perf/builtin-record.c | 14 +++++++++++++- 2 files changed, 16 insertions(+), 1 deletion(-) diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt index 680396c56bd1..dac53ece51ab 100644 --- a/tools/perf/Documentation/perf-record.txt +++ b/tools/perf/Documentation/perf-record.txt @@ -388,6 +388,9 @@ 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 3ff9d972225e..4e8e97928f05 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -912,6 +912,7 @@ 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; /* @@ -921,7 +922,18 @@ 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 all (non-dummy) evsel have exclude_user, + * system_wide is not needed. + */ + if (!!opts->target.cpu_list && !opts->all_kernel) + system_wide = true; + + evsel = evlist__findnew_tracking_event(evlist, system_wide); if (!evsel) return -ENOMEM;