From nobody Thu Dec 18 22:15:24 2025 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 48111C77B75 for ; Tue, 2 May 2023 22:39:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229911AbjEBWjc (ORCPT ); Tue, 2 May 2023 18:39:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229914AbjEBWj3 (ORCPT ); Tue, 2 May 2023 18:39:29 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9672330EF for ; Tue, 2 May 2023 15:39:23 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 3f1490d57ef6-b9a6f15287eso552930276.1 for ; Tue, 02 May 2023 15:39:23 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20221208; t=1683067162; x=1685659162; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=3DVy621GYiHB+6fU/268WLthwNlggN6c1xnlL0X7vU8=; b=F6p59By143t7B3onb48y5PrfMz0WvsnIWHgCmD9MSxEWtEoyWMZBByqL8R6C+3OA+6 GYmETQATKFApIE3MqIC3PpZSbayv4fLLr5HSedHZKt+vl49KkesehX9831R2t7hBR12M p3PLLquC+0/l7r56IqqF/iE8M13faTyrWpUrOLh4XFHIIHjkJV1eW5L2JewOM8VBAOca n8pGb4GlejDAL/Um+ht/lPCtrgM/fCHSkkRXcBkvGO6b+Lq/CBKPHUn7t57NYpFHtvJ6 O0rA+gv5ki5084ux2LkRMoyYOJl7zmsri5HMJETxlsbcSUojA3Z8R0tJkVi6x9IUmi8l 69Cg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683067162; x=1685659162; h=cc:to:from:subject:references:mime-version:message-id:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=3DVy621GYiHB+6fU/268WLthwNlggN6c1xnlL0X7vU8=; b=Y2Kh1TH7RCoClkubfYBmC3ACgu70WD/aPEkxwod/b1x7syKQhhvniYRmULy63RGYZf DGYCc3aj6yEOs9+Kg1Q3RFw4gi63+cKdrv3tlKhOESaqIuCDzd/wH5fQegS+jHBqs1LU NukzijplC/Fm5AOZ0yX52KHLdioMgfDUYnZfm7jPEFs/mdVu3DX4UZQRfqlx1oynpS/B sQ+fflW4XVGls71+GXsFlSyB09Kd7DOVjw0pxrK9Xd+o+jZIOQ9map6XRPGsxLfMaK3t zN2tsZa4FHtKhwKjvDleWoXyF//yP6waiyOK6UGxkXhOmBy29VKnXQuQMsMfhyDuSGrR wrgQ== X-Gm-Message-State: AC+VfDz2uahH7mj+Pm0gQQkaaDtqBhn+4srlXix+Di1h4MmpEQCEhRML f+5jCeMwlAzpbKtjPE4rRcQ8omWr08g+ X-Google-Smtp-Source: ACHHUZ6cVYw3nZo5XIGdjainuFtVO48FoXiCiFFHyRkiYuxelQ7ivnKAP1bI1zNMiXDo9Hr9UN9E3qkTu8gh X-Received: from irogers.svl.corp.google.com ([2620:15c:2d4:203:e70c:446b:d23b:982e]) (user=irogers job=sendgmr) by 2002:a05:690c:2887:b0:544:bbd2:74be with SMTP id ee7-20020a05690c288700b00544bbd274bemr84312ywb.4.1683067162600; Tue, 02 May 2023 15:39:22 -0700 (PDT) Date: Tue, 2 May 2023 15:38:09 -0700 In-Reply-To: <20230502223851.2234828-1-irogers@google.com> Message-Id: <20230502223851.2234828-3-irogers@google.com> Mime-Version: 1.0 References: <20230502223851.2234828-1-irogers@google.com> X-Mailer: git-send-email 2.40.1.495.gc816e09b53d-goog Subject: [PATCH v4 02/44] perf stat: Introduce skippable evsels From: Ian Rogers To: Arnaldo Carvalho de Melo , Kan Liang , Ahmad Yasin , Peter Zijlstra , Ingo Molnar , Stephane Eranian , Andi Kleen , Perry Taylor , Samantha Alt , Caleb Biggers , Weilin Wang , Edward Baker , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Adrian Hunter , Florian Fischer , Rob Herring , Zhengjun Xing , John Garry , Kajol Jain , Sumanth Korikkar , Thomas Richter , Tiezhu Yang , Ravi Bangoria , Leo Yan , Yang Jihong , James Clark , Suzuki Poulouse , Kang Minchul , Athira Rajeev , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Ian Rogers Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Perf stat with no arguments will use default events and metrics. These events may fail to open even with kernel and hypervisor disabled. When these fail then the permissions error appears even though they were implicitly selected. This is particularly a problem with the automatic selection of the TopdownL1 metric group on certain architectures like Skylake: ''' $ perf stat true Error: Access to performance monitoring and observability operations is limited. Consider adjusting /proc/sys/kernel/perf_event_paranoid setting to open access to performance monitoring and observability operations for processes without CAP_PERFMON, CAP_SYS_PTRACE or CAP_SYS_ADMIN Linux capability. More information can be found at 'Perf events and tool security' document: https://www.kernel.org/doc/html/latest/admin-guide/perf-security.html perf_event_paranoid setting is 2: -1: Allow use of (almost) all events by all users Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK >=3D 0: Disallow raw and ftrace function tracepoint access >=3D 1: Disallow CPU event access >=3D 2: Disallow kernel profiling To make the adjusted perf_event_paranoid setting permanent preserve it in /etc/sysctl.conf (e.g. kernel.perf_event_paranoid =3D ) ''' This patch adds skippable evsels that when they fail to open won't cause termination and will appear as "" in output. The TopdownL1 events, from the metric group, are marked as skippable. This turns the failure above to: ''' $ perf stat perf bench internals synthesize Computing performance of single threaded perf event synthesis by synthesizing events on the perf process itself: Average synthesis took: 49.287 usec (+- 0.083 usec) Average num. events: 3.000 (+- 0.000) Average time per event 16.429 usec Average data synthesis took: 49.641 usec (+- 0.085 usec) Average num. events: 11.000 (+- 0.000) Average time per event 4.513 usec Performance counter stats for 'perf bench internals synthesize': 1,222.38 msec task-clock:u # 0.993 CPUs ut= ilized 0 context-switches:u # 0.000 /sec 0 cpu-migrations:u # 0.000 /sec 162 page-faults:u # 132.529 /sec 774,445,184 cycles:u # 0.634 GHz = (49.61%) 1,640,969,811 instructions:u # 2.12 insn pe= r cycle (59.67%) 302,052,148 branches:u # 247.102 M/sec = (59.69%) 1,807,718 branch-misses:u # 0.60% of all = branches (59.68%) 5,218,927 CPU_CLK_UNHALTED.REF_XCLK:u # 4.269 M/sec # 17.3 % tma_fronten= d_bound # 56.4 % tma_retiring # nan % tma_backend= _bound # nan % tma_bad_spe= culation (60.01%) 536,580,469 IDQ_UOPS_NOT_DELIVERED.CORE:u # 438.965 M/sec = (60.33%) INT_MISC.RECOVERY_CYCLES_ANY:u 5,223,936 CPU_CLK_UNHALTED.ONE_THREAD_ACTIVE:u # 4.274 M/s= ec (40.31%) 774,127,250 CPU_CLK_UNHALTED.THREAD:u # 633.297 M/sec = (50.34%) 1,746,579,518 UOPS_RETIRED.RETIRE_SLOTS:u # 1.429 G/sec = (50.12%) 1,940,625,702 UOPS_ISSUED.ANY:u # 1.588 G/sec = (49.70%) 1.231055525 seconds time elapsed 0.258327000 seconds user 0.965749000 seconds sys ''' The event INT_MISC.RECOVERY_CYCLES_ANY:u is skipped as it can't be opened with paranoia 2 on Skylake. With a lower paranoia, or as root, all events/metrics are computed. Signed-off-by: Ian Rogers Tested-by: Kan Liang --- tools/perf/builtin-stat.c | 38 +++++++++++++++++++++++++++++--------- tools/perf/util/evsel.c | 15 +++++++++++++-- tools/perf/util/evsel.h | 1 + 3 files changed, 43 insertions(+), 11 deletions(-) diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index be9677aa642f..ffb47b166098 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -667,6 +667,13 @@ static enum counter_recovery stat_handle_error(struct = evsel *counter) evsel_list->core.threads->err_thread =3D -1; return COUNTER_RETRY; } + } else if (counter->skippable) { + if (verbose > 0) + ui__warning("skipping event %s that kernel failed to open .\n", + evsel__name(counter)); + counter->supported =3D false; + counter->errored =3D true; + return COUNTER_SKIP; } =20 evsel__open_strerror(counter, &target, errno, msg, sizeof(msg)); @@ -1890,15 +1897,28 @@ static int add_default_attributes(void) * caused by exposing latent bugs. This is fixed properly in: * https://lore.kernel.org/lkml/bff481ba-e60a-763f-0aa0-3ee53302c480@lin= ux.intel.com/ */ - if (metricgroup__has_metric("TopdownL1") && !perf_pmu__has_hybrid() && - metricgroup__parse_groups(evsel_list, "TopdownL1", - /*metric_no_group=3D*/false, - /*metric_no_merge=3D*/false, - /*metric_no_threshold=3D*/true, - stat_config.user_requested_cpu_list, - stat_config.system_wide, - &stat_config.metric_events) < 0) - return -1; + if (metricgroup__has_metric("TopdownL1") && !perf_pmu__has_hybrid()) { + struct evlist *metric_evlist =3D evlist__new(); + struct evsel *metric_evsel; + + if (!metric_evlist) + return -1; + + if (metricgroup__parse_groups(metric_evlist, "TopdownL1", + /*metric_no_group=3D*/false, + /*metric_no_merge=3D*/false, + /*metric_no_threshold=3D*/true, + stat_config.user_requested_cpu_list, + stat_config.system_wide, + &stat_config.metric_events) < 0) + return -1; + + evlist__for_each_entry(metric_evlist, metric_evsel) { + metric_evsel->skippable =3D true; + } + evlist__splice_list_tail(evsel_list, &metric_evlist->core.entries); + evlist__delete(metric_evlist); + } =20 /* Platform specific attrs */ if (evlist__add_default_attrs(evsel_list, default_null_attrs) < 0) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 356c07f03be6..1cd04b5998d2 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -290,6 +290,7 @@ void evsel__init(struct evsel *evsel, evsel->per_pkg_mask =3D NULL; evsel->collect_stat =3D false; evsel->pmu_name =3D NULL; + evsel->skippable =3D false; } =20 struct evsel *evsel__new_idx(struct perf_event_attr *attr, int idx) @@ -1725,9 +1726,13 @@ static int get_group_fd(struct evsel *evsel, int cpu= _map_idx, int thread) return -1; =20 fd =3D FD(leader, cpu_map_idx, thread); - BUG_ON(fd =3D=3D -1); + BUG_ON(fd =3D=3D -1 && !leader->skippable); =20 - return fd; + /* + * When the leader has been skipped, return -2 to distinguish from no + * group leader case. + */ + return fd =3D=3D -1 ? -2 : fd; } =20 static void evsel__remove_fd(struct evsel *pos, int nr_cpus, int nr_thread= s, int thread_idx) @@ -2109,6 +2114,12 @@ static int evsel__open_cpu(struct evsel *evsel, stru= ct perf_cpu_map *cpus, =20 group_fd =3D get_group_fd(evsel, idx, thread); =20 + if (group_fd =3D=3D -2) { + pr_debug("broken group leader for %s\n", evsel->name); + err =3D -EINVAL; + goto out_close; + } + test_attr__ready(); =20 /* Debug message used by test scripts */ diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index 35805dcdb1b9..bf8f01af1c0b 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -95,6 +95,7 @@ struct evsel { bool weak_group; bool bpf_counter; bool use_config_name; + bool skippable; int bpf_fd; struct bpf_object *bpf_obj; struct list_head config_terms; --=20 2.40.1.495.gc816e09b53d-goog