From nobody Mon Feb 9 19:25:49 2026 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 16EBEEB64DA for ; Tue, 4 Jul 2023 07:44:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231532AbjGDHov (ORCPT ); Tue, 4 Jul 2023 03:44:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55244 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231459AbjGDHoa (ORCPT ); Tue, 4 Jul 2023 03:44:30 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E766CE6D; Tue, 4 Jul 2023 00:44:23 -0700 (PDT) Received: from kwepemm600003.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4QwFCD5pDkzTm8c; Tue, 4 Jul 2023 15:43:20 +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; Tue, 4 Jul 2023 15:44:21 +0800 From: Yang Jihong To: , , , , , , , , , , , CC: Subject: [PATCH 3/5] perf record: Tracking side-band events for all CPUs when tracing selected CPUs Date: Tue, 4 Jul 2023 07:42:15 +0000 Message-ID: <20230704074217.240939-4-yangjihong1@huawei.com> X-Mailer: git-send-email 2.30.GIT In-Reply-To: <20230704074217.240939-1-yangjihong1@huawei.com> References: <20230704074217.240939-1-yangjihong1@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Originating-IP: [10.67.174.95] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemm600003.china.huawei.com (7.193.23.202) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" 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=3D3 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 =3D 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 =3D 6 sys_perf_event_open: pid -1 cpu 1 group_fd -1 flags 0x8 =3D 7 sys_perf_event_open: pid -1 cpu 2 group_fd -1 flags 0x8 =3D 9 sys_perf_event_open: pid -1 cpu 3 group_fd -1 flags 0x8 =3D 10 sys_perf_event_open: pid -1 cpu 4 group_fd -1 flags 0x8 =3D 11 sys_perf_event_open: pid -1 cpu 5 group_fd -1 flags 0x8 =3D 12 sys_perf_event_open: pid -1 cpu 6 group_fd -1 flags 0x8 =3D 13 sys_perf_event_open: pid -1 cpu 7 group_fd -1 flags 0x8 =3D 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); } =20 +static int record__config_tracking_events(struct record *rec) +{ + struct evsel *evsel; + struct evlist *evlist =3D rec->evlist; + struct record_opts *opts =3D &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) { + evsel =3D evlist__findnew_tracking_event(evlist); + if (!evsel) + return -ENOMEM; + + if (!evsel->core.system_wide) { + evsel->core.system_wide =3D true; + evsel__set_sample_bit(evsel, TIME); + perf_evlist__propagate_maps(&evlist->core, &evsel->core); + } + } + + 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; } =20 + err =3D record__config_tracking_events(rec); + if (err) { + pr_err("record__config_tracking_events failed, error %d\n", err); + goto out; + } + err =3D record__init_thread_masks(rec); if (err) { pr_err("Failed to initialize parallel data streaming masks\n"); --=20 2.30.GIT