From nobody Wed Jan 22 10:52:26 2025 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BDA161FA150; Wed, 22 Jan 2025 02:32:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737513153; cv=none; b=Q16Jb7mOFSU01hjIwoXbYxWbFP4mu1e0rM3eUGQkumAO89YR28lCHCMWkp5VQMhEQT7vzvtb8nE4GRMeqXhp+PLvvtZUwhoJ8xiu2ZvGC0Rv1w5pD147l4vI2bGXUmWzpJ4p1Y3dbybTRoA30ITCo23PgFmuPNgmZ/yN4V8h/PY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1737513153; c=relaxed/simple; bh=uQkriTpbv5xsQRFM+z/ztvmuKCsCVHw581yTqgar7aM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eoW60IEeAzSoJKC6ihVyK93ndJIJDm6eO2uDjJE9HwrkFjDNDaEX/8atsJRDm1c+pn1N1BYfVe/fkIB2WLdHgMZ+22WjRXEit2SaDtK7cV1PW8f8A1nLeHWnq9mBjcZYCCFbG56OY117ksLZgMccnPK/wCp7T//IpWbWkw9o+r4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=r0Dc8Dnd; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="r0Dc8Dnd" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 19006C4CEDF; Wed, 22 Jan 2025 02:32:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1737513152; bh=uQkriTpbv5xsQRFM+z/ztvmuKCsCVHw581yTqgar7aM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=r0Dc8DndFHN9H320zL9b6Ez3/+/ciLSVzzMWVeNKc9M14Zrdw+qWl7YJgPjjKuOJp rMDFUB0+omkZqhWA9qMnqEI7SQRIA9OsLh7vN5QOb7WhGYofeXcBTg9jXh4qTqYz5d 6pvPkYW+uUMmobaWhiO4Oy+3G2pk9OHJgTEWf9djeznhoVvdwBpuY89SmVAvEkv5QE eIfIesvIfOjfsLDUf/PHDZPbVXZyOJr0kiSME2qr1issMrM5BSigtUYbSDFn+KhCST zdbwCYTFK9ZFkuvUkB7tUIXepwOk4RRRf+lFfCXqLog5JV23KIj8MyOREHnGvbwYae K15p471mPnRLw== From: Josh Poimboeuf To: x86@kernel.org Cc: Peter Zijlstra , Steven Rostedt , Ingo Molnar , Arnaldo Carvalho de Melo , linux-kernel@vger.kernel.org, Indu Bhagat , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Ian Rogers , Adrian Hunter , linux-perf-users@vger.kernel.org, Mark Brown , linux-toolchains@vger.kernel.org, Jordan Rome , Sam James , linux-trace-kernel@vger.kernel.org, Andrii Nakryiko , Jens Remus , Mathieu Desnoyers , Florian Weimer , Andy Lutomirski , Masami Hiramatsu , Weinan Liu Subject: [PATCH v4 37/39] perf record: Enable defer_callchain for user callchains Date: Tue, 21 Jan 2025 18:31:29 -0800 Message-ID: X-Mailer: git-send-email 2.48.1 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Namhyung Kim And add the missing feature detection logic to clear the flag on old kernels. $ perf record -g -vv true ... ------------------------------------------------------------ perf_event_attr: type 0 (PERF_TYPE_HARDWARE) size 136 config 0 (PERF_COUNT_HW_CPU_CYCLES) { sample_period, sample_freq } 4000 sample_type IP|TID|TIME|CALLCHAIN|PERIOD read_format ID|LOST disabled 1 inherit 1 mmap 1 comm 1 freq 1 enable_on_exec 1 task 1 sample_id_all 1 mmap2 1 comm_exec 1 ksymbol 1 bpf_event 1 defer_callchain 1 ------------------------------------------------------------ sys_perf_event_open: pid 162755 cpu 0 group_fd -1 flags 0x8 sys_perf_event_open failed, error -22 switching off deferred callchain support Signed-off-by: Namhyung Kim Signed-off-by: Josh Poimboeuf --- tools/perf/util/evsel.c | 24 ++++++++++++++++++++++++ tools/perf/util/evsel.h | 1 + 2 files changed, 25 insertions(+) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 09b9735f2fb1..e3be3cc7632d 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -998,6 +998,14 @@ static void __evsel__config_callchain(struct evsel *ev= sel, struct record_opts *o } } =20 + if (param->record_mode =3D=3D CALLCHAIN_FP && !attr->exclude_callchain_us= er) { + /* + * Enable deferred callchains optimistically. It'll be switched + * off later if the kernel doesn't support it. + */ + attr->defer_callchain =3D 1; + } + if (function) { pr_info("Disabling user space callchains for function trace event.\n"); attr->exclude_callchain_user =3D 1; @@ -2038,6 +2046,8 @@ static int __evsel__prepare_open(struct evsel *evsel,= struct perf_cpu_map *cpus, =20 static void evsel__disable_missing_features(struct evsel *evsel) { + if (perf_missing_features.defer_callchain) + evsel->core.attr.defer_callchain =3D 0; if (perf_missing_features.inherit_sample_read && evsel->core.attr.inherit= && (evsel->core.attr.sample_type & PERF_SAMPLE_READ)) evsel->core.attr.inherit =3D 0; @@ -2244,6 +2254,15 @@ static bool evsel__detect_missing_features(struct ev= sel *evsel) =20 /* Please add new feature detection here. */ =20 + attr.defer_callchain =3D true; + attr.sample_type =3D PERF_SAMPLE_CALLCHAIN; + if (has_attr_feature(&attr, /*flags=3D*/0)) + goto found; + perf_missing_features.defer_callchain =3D true; + pr_debug2("switching off deferred callchain support\n"); + attr.defer_callchain =3D false; + attr.sample_type =3D 0; + attr.inherit =3D true; attr.sample_type =3D PERF_SAMPLE_READ; if (has_attr_feature(&attr, /*flags=3D*/0)) @@ -2355,6 +2374,11 @@ static bool evsel__detect_missing_features(struct ev= sel *evsel) errno =3D old_errno; =20 check: + if (evsel->core.attr.defer_callchain && + evsel->core.attr.sample_type & PERF_SAMPLE_CALLCHAIN && + perf_missing_features.defer_callchain) + return true; + if (evsel->core.attr.inherit && (evsel->core.attr.sample_type & PERF_SAMPLE_READ) && perf_missing_features.inherit_sample_read) diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index 04934a7af174..b90a970f9a30 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -206,6 +206,7 @@ struct perf_missing_features { bool read_lost; bool branch_counters; bool inherit_sample_read; + bool defer_callchain; }; =20 extern struct perf_missing_features perf_missing_features; --=20 2.48.1