From nobody Thu Dec 18 07:20:15 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 DC06DC197A0 for ; Tue, 21 Nov 2023 00:04:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232598AbjKUAEa (ORCPT ); Mon, 20 Nov 2023 19:04:30 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37428 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229490AbjKUAE2 (ORCPT ); Mon, 20 Nov 2023 19:04:28 -0500 Received: from mail-yw1-x1149.google.com (mail-yw1-x1149.google.com [IPv6:2607:f8b0:4864:20::1149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DAC6695 for ; Mon, 20 Nov 2023 16:04:24 -0800 (PST) Received: by mail-yw1-x1149.google.com with SMTP id 00721157ae682-5c994880223so30990637b3.0 for ; Mon, 20 Nov 2023 16:04:24 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1700525064; x=1701129864; darn=vger.kernel.org; h=to:from:subject:mime-version:message-id:date:from:to:cc:subject :date:message-id:reply-to; bh=ZCOnJaz0EAvoHbURgEibZw+mVElLQgmjJxMJmfh1m6s=; b=TmuvYQsKAJQJZzDkHKjz+BV8Uwe24eNYQq+mK8B1oFZb3bG8+WdF3roTc3A5wVLGg8 rFTIrFK0j1iT8C83sRGVp+HrVkolOui2sCcsl698CTEQt31HcygZ9OpSC33at5h8Um0/ 0W8kZ9bzno0NJTQXj2PcC/2QWkui1DrTaXpjc8iUp+1XchkQExJAQqSJmRtxud1/heh5 iAmv59qMd/rWDxqlNnlF+kcU97V30zNLoyt5nQTPak6uywMRKNINORT1sTfUTWNrk5PQ sCiq10qlcdkK1kEPRyek1XTt9Zz49VC9ayVhNjYNIpqd/BkN67LKgf6QmJ6tvishLVnB 2iRA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1700525064; x=1701129864; h=to:from:subject:mime-version:message-id:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=ZCOnJaz0EAvoHbURgEibZw+mVElLQgmjJxMJmfh1m6s=; b=KVKRhqU41Wphpc3SuOWwIDfvSOkAn6iApmZmHlcGfie//1583fcvWxS8TNODyHMduV f5ZT2h1jLGOKR0CSnngBGGZnjoBLu/pZu5jNcOGr8Pjo17k25TmjBT6x21rKagoWTADE oV+nnCxUlfpULmBX8Flu/mGByv3Nf8PeGvuDWBgFlUhvRZe+k5o1AUutssTU1ggcZ0tk msy+pLwMxIrSDf5t9caYfyWiBrW5MXb6ajaEULrSizs9y3oNz1v22dDpRDVPy+ioMWjF +DCLeO/av+t/spq/6Fv4zY0nELz7/pXcDZKpHWfs/E/S+/w+rhArtGPjcvuVxg1iMXbF Q3JQ== X-Gm-Message-State: AOJu0YxPAK6g/Yr7ukOg1t+DHGhoWzTHX48hueuV9N/AwyAEpyXLD6MK jDVfOoQowXxmgsA3OEYJU9vWc2HjzJCU X-Google-Smtp-Source: AGHT+IGZuQayuCjQP5dz/h24rjY1hkIw1a8Z19AVZJreAbOPUa3gynFThusK5ZvC3dGpVbHo8Ov07h9bIRaB X-Received: from irogers.svl.corp.google.com ([2620:15c:2a3:200:9c08:6dab:5948:ab06]) (user=irogers job=sendgmr) by 2002:a0d:c981:0:b0:59b:c811:a709 with SMTP id l123-20020a0dc981000000b0059bc811a709mr270383ywd.0.1700525063964; Mon, 20 Nov 2023 16:04:23 -0800 (PST) Date: Mon, 20 Nov 2023 16:04:20 -0800 Message-Id: <20231121000420.368075-1-irogers@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.43.0.rc1.413.gea7ed67945-goog Subject: [RFC PATCH v2] perf evsel: Fallback to task-clock when not system wide From: Ian Rogers To: Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , Kan Liang , Yang Jihong , Leo Yan , Sandipan Das , Ravi Bangoria , linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Ajay Kaher , Alexey Makhalov Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When the cycles event isn't available evsel will fallback to the cpu-clock software event. task-clock is similar to cpu-clock but only runs when the process is running. Falling back to cpu-clock when not system wide leads to confusion, by falling back to task-clock it is hoped the confusion is less. Pass the target to determine if task-clock is more appropriate. Update a nearby comment and debug string for the change. Acked-by: Namhyung Kim Tested-by: Athira Rajeev --- v2. Use target__has_cpu as suggested by Namhyung. https://lpc.events/event/17/contributions/1556/ Signed-off-by: Ian Rogers --- tools/perf/builtin-record.c | 2 +- tools/perf/builtin-stat.c | 2 +- tools/perf/builtin-top.c | 2 +- tools/perf/util/evsel.c | 18 ++++++++++-------- tools/perf/util/evsel.h | 3 ++- 5 files changed, 15 insertions(+), 12 deletions(-) diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c index 8ec818568662..d8bb59511fdd 100644 --- a/tools/perf/builtin-record.c +++ b/tools/perf/builtin-record.c @@ -1350,7 +1350,7 @@ static int record__open(struct record *rec) evlist__for_each_entry(evlist, pos) { try_again: if (evsel__open(pos, pos->core.cpus, pos->core.threads) < 0) { - if (evsel__fallback(pos, errno, msg, sizeof(msg))) { + if (evsel__fallback(pos, &opts->target, errno, msg, sizeof(msg))) { if (verbose > 0) ui__warning("%s\n", msg); goto try_again; diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index a3af805a1d57..d8e5d6f7a87a 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -653,7 +653,7 @@ static enum counter_recovery stat_handle_error(struct e= vsel *counter) if ((evsel__leader(counter) !=3D counter) || !(counter->core.leader->nr_members > 1)) return COUNTER_SKIP; - } else if (evsel__fallback(counter, errno, msg, sizeof(msg))) { + } else if (evsel__fallback(counter, &target, errno, msg, sizeof(msg))) { if (verbose > 0) ui__warning("%s\n", msg); return COUNTER_RETRY; diff --git a/tools/perf/builtin-top.c b/tools/perf/builtin-top.c index ea8c7eca5eee..1e42bd1c7d5a 100644 --- a/tools/perf/builtin-top.c +++ b/tools/perf/builtin-top.c @@ -1044,7 +1044,7 @@ static int perf_top__start_counters(struct perf_top *= top) perf_top_overwrite_fallback(top, counter)) goto try_again; =20 - if (evsel__fallback(counter, errno, msg, sizeof(msg))) { + if (evsel__fallback(counter, &opts->target, errno, msg, sizeof(msg))) { if (verbose > 0) ui__warning("%s\n", msg); goto try_again; diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index a5da74e3a517..532f34d9fcb5 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -2853,7 +2853,8 @@ u64 evsel__intval_common(struct evsel *evsel, struct = perf_sample *sample, const =20 #endif =20 -bool evsel__fallback(struct evsel *evsel, int err, char *msg, size_t msgsi= ze) +bool evsel__fallback(struct evsel *evsel, struct target *target, int err, + char *msg, size_t msgsize) { int paranoid; =20 @@ -2861,18 +2862,19 @@ bool evsel__fallback(struct evsel *evsel, int err, = char *msg, size_t msgsize) evsel->core.attr.type =3D=3D PERF_TYPE_HARDWARE && evsel->core.attr.config =3D=3D PERF_COUNT_HW_CPU_CYCLES) { /* - * If it's cycles then fall back to hrtimer based - * cpu-clock-tick sw counter, which is always available even if - * no PMU support. + * If it's cycles then fall back to hrtimer based cpu-clock sw + * counter, which is always available even if no PMU support. * * PPC returns ENXIO until 2.6.37 (behavior changed with commit * b0a873e). */ - scnprintf(msg, msgsize, "%s", -"The cycles event is not supported, trying to fall back to cpu-clock-ticks= "); - evsel->core.attr.type =3D PERF_TYPE_SOFTWARE; - evsel->core.attr.config =3D PERF_COUNT_SW_CPU_CLOCK; + evsel->core.attr.config =3D target__has_cpu(target) + ? PERF_COUNT_SW_CPU_CLOCK + : PERF_COUNT_SW_TASK_CLOCK; + scnprintf(msg, msgsize, + "The cycles event is not supported, trying to fall back to %s", + target__has_cpu(target) ? "cpu-clock" : "task-clock"); =20 zfree(&evsel->name); return true; diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index f19ac9f027ef..efbb6e848287 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -460,7 +460,8 @@ static inline bool evsel__is_clock(const struct evsel *= evsel) evsel__match(evsel, SOFTWARE, SW_TASK_CLOCK); } =20 -bool evsel__fallback(struct evsel *evsel, int err, char *msg, size_t msgsi= ze); +bool evsel__fallback(struct evsel *evsel, struct target *target, int err, + char *msg, size_t msgsize); int evsel__open_strerror(struct evsel *evsel, struct target *target, int err, char *msg, size_t size); =20 --=20 2.43.0.rc1.413.gea7ed67945-goog