From nobody Mon Feb 9 04:14:24 2026 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2A13247A6C; Fri, 22 Mar 2024 13:04:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711112680; cv=none; b=npy0skV+FyyDdCT/EQwNSeZWCIAoGB+Mc2LSTxKOGEyTzeIFCRKIKHfeX/M/oL4O0oFqP7aaHXUOK8dhRpefNCM8Cw4jwFsMLWGqUBtHaHLU3mv9lJS6t/Zr4NB3qGMdLNGOHfLap0LCpofEzPX4LwfMRjVS6hJDHlXFPhA5u08= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711112680; c=relaxed/simple; bh=Dv5y6LBmAVPIZvvpOpnDqf7nw2vZ7U/HBRtWSqL345I=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uaCOlzEykKHJCcKSAOcIsmpnDIbRtcVSirhra9wOFdFeWFACpJrYC4rcgciHVYxWKMMBAyXDVQEBRtCtR0vJha7Y4IXlcQYCfW2nsQtjv6AFyreNXmId0lBEZ/AzC39ejz1fxqX/s8pXCaa82tGanx6xvSCKS4Loenx0QgoTqog= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id CCEFA1692; Fri, 22 Mar 2024 06:05:11 -0700 (PDT) Received: from e126817.cambridge.arm.com (e126817.cambridge.arm.com [10.2.3.5]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id F0BE13F762; Fri, 22 Mar 2024 06:04:35 -0700 (PDT) From: Ben Gainey To: peterz@infradead.org, mingo@redhat.com, acme@kernel.org, namhyung@kernel.org Cc: james.clark@arm.com, mark.rutland@arm.com, alexander.shishkin@linux.intel.com, jolsa@kernel.org, irogers@google.com, adrian.hunter@intel.com, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Ben Gainey Subject: [PATCH v3 4/4] tools/perf: Allow inherit + inherit_stat + PERF_SAMPLE_READ when opening events Date: Fri, 22 Mar 2024 13:04:14 +0000 Message-ID: <20240322130414.70186-5-ben.gainey@arm.com> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240322130414.70186-1-ben.gainey@arm.com> References: <20240322130414.70186-1-ben.gainey@arm.com> 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" This change updates evsel to allow the combination of inherit and PERF_SAMPLE_READ. A fallback is implemented for kernel versions where this feature is not supported. The user must pass --stat option to perf record to opt into this new behaviour. Signed-off-by: Ben Gainey --- tools/perf/tests/attr/base-record | 2 +- tools/perf/tests/attr/base-stat | 2 +- tools/perf/tests/attr/system-wide-dummy | 2 +- tools/perf/tests/attr/test-record-dummy-C0 | 2 +- .../test-record-group-sampling-inherit-stat | 62 ++++++++++++++ tools/perf/util/evsel.c | 82 ++++++++++++++++++- tools/perf/util/evsel.h | 1 + 7 files changed, 147 insertions(+), 6 deletions(-) create mode 100644 tools/perf/tests/attr/test-record-group-sampling-inheri= t-stat diff --git a/tools/perf/tests/attr/base-record b/tools/perf/tests/attr/base= -record index b44e4e6e4443..dd76fbdb628f 100644 --- a/tools/perf/tests/attr/base-record +++ b/tools/perf/tests/attr/base-record @@ -5,7 +5,7 @@ group_fd=3D-1 flags=3D0|8 cpu=3D* type=3D0|1 -size=3D136 +size=3D144 config=3D0|1 sample_period=3D* sample_type=3D263 diff --git a/tools/perf/tests/attr/base-stat b/tools/perf/tests/attr/base-s= tat index fccd8ec4d1b0..d769e69bb4f5 100644 --- a/tools/perf/tests/attr/base-stat +++ b/tools/perf/tests/attr/base-stat @@ -5,7 +5,7 @@ group_fd=3D-1 flags=3D0|8 cpu=3D* type=3D0 -size=3D136 +size=3D144 config=3D0 sample_period=3D0 sample_type=3D65536 diff --git a/tools/perf/tests/attr/system-wide-dummy b/tools/perf/tests/att= r/system-wide-dummy index a1e1d6a263bf..9806de3d9c9e 100644 --- a/tools/perf/tests/attr/system-wide-dummy +++ b/tools/perf/tests/attr/system-wide-dummy @@ -7,7 +7,7 @@ cpu=3D* pid=3D-1 flags=3D8 type=3D1 -size=3D136 +size=3D144 config=3D9 sample_period=3D1 # PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_TIME | diff --git a/tools/perf/tests/attr/test-record-dummy-C0 b/tools/perf/tests/= attr/test-record-dummy-C0 index 576ec48b3aaf..87f5c8db5ba1 100644 --- a/tools/perf/tests/attr/test-record-dummy-C0 +++ b/tools/perf/tests/attr/test-record-dummy-C0 @@ -10,7 +10,7 @@ cpu=3D0 pid=3D-1 flags=3D8 type=3D1 -size=3D136 +size=3D144 config=3D9 sample_period=3D4000 # PERF_SAMPLE_IP | PERF_SAMPLE_TID | PERF_SAMPLE_TIME | diff --git a/tools/perf/tests/attr/test-record-group-sampling-inherit-stat = b/tools/perf/tests/attr/test-record-group-sampling-inherit-stat new file mode 100644 index 000000000000..281a17acb6ae --- /dev/null +++ b/tools/perf/tests/attr/test-record-group-sampling-inherit-stat @@ -0,0 +1,62 @@ +[config] +command =3D record +args =3D --stat --no-bpf-event -c 10000 -e '{cycles,cache-misses}:S' ki= ll >/dev/null 2>&1 +ret =3D 1 + +[event-1:base-record] +fd=3D1 +group_fd=3D-1 + +# cycles +type=3D0 +config=3D0 + +# default | PERF_SAMPLE_READ +sample_type=3D87 + +# PERF_FORMAT_ID | PERF_FORMAT_GROUP | PERF_FORMAT_LOST | PERF_FORMAT_TOT= AL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING +read_format=3D31 +task=3D1 +mmap=3D1 +comm=3D1 +enable_on_exec=3D1 +disabled=3D1 + +# inherit is enabled for group sampling, as is inherit_stat +inherit=3D1 +inherit_stat=3D1 + +# sampling disabled +sample_freq=3D0 +sample_period=3D10000 +freq=3D0 +write_backward=3D0 + +[event-2:base-record] +fd=3D2 +group_fd=3D1 + +# cache-misses +type=3D0 +config=3D3 + +# default | PERF_SAMPLE_READ +sample_type=3D87 + +# PERF_FORMAT_ID | PERF_FORMAT_GROUP | PERF_FORMAT_LOST | PERF_FORMAT_TOT= AL_TIME_ENABLED | PERF_FORMAT_TOTAL_TIME_RUNNING +read_format=3D31 +task=3D0 +mmap=3D0 +comm=3D0 +enable_on_exec=3D0 +disabled=3D0 + +# inherit is enabled for group sampling, as is inherit_stat +inherit=3D1 +inherit_stat=3D1 + +# sampling disabled +sample_freq=3D0 +sample_period=3D0 +freq=3D0 +write_backward=3D0 diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index 6d7c9c58a9bc..aec6b4f5264e 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -1097,6 +1097,64 @@ static bool evsel__is_offcpu_event(struct evsel *evs= el) return evsel__is_bpf_output(evsel) && evsel__name_is(evsel, OFFCPU_EVENT); } =20 +static bool evsel__has_term_type(struct evsel *evsel, enum evsel_term_type= type) +{ + return __evsel__get_config_term(evsel, type) !=3D NULL; +} + +/* + * Determine whether or not an evsel can support inherit+inherit_stat+PERF= _SAMPLE_READ. + * + * In order not to break existing command line behaviour, this configurati= on + * will only be enabled if certain specific requirements are met: + * + * 1) When making a system-wide capture, there is no need to support this + * configuration. Likewise, if the user disables inherit, or does not r= equest + * inherit_stat, then the configuration is not supported. + * 2) If the user explicitly specifies 'freq' as a config term, then do not + * support this feature, as frequency counters are not compatible. + * 3) If the user explicitly specifies 'period' as a config term, then the + * feature is compatible with that event. + * 4) If neither was explicitly set, and the event is part of a group, then + * base the decision on the leader. + * 5) Otherwise base the decision on whether or not the user specified a p= eriod + * or frequency on the command line (which includes the default frequen= cy + * setting). + */ +static bool evsel__compat_with_inherit_sample_read(struct record_opts *opt= s, + struct evsel *leader, + struct evsel *evsel) +{ + struct perf_event_attr *attr =3D &evsel->core.attr; + + if (opts->target.system_wide) + return false; + + if (opts->no_inherit_set || !opts->inherit_stat) + return false; + + if (evsel__has_term_type(evsel, EVSEL__CONFIG_TERM_FREQ)) + return false; + + if (evsel__has_term_type(evsel, EVSEL__CONFIG_TERM_PERIOD)) + return true; + + if (leader && (leader !=3D evsel)) { + struct perf_event_attr *ldr_att =3D &leader->core.attr; + + if (evsel__has_term_type(leader, EVSEL__CONFIG_TERM_FREQ)) + return false; + + if (evsel__has_term_type(leader, EVSEL__CONFIG_TERM_PERIOD)) + return true; + + if (ldr_att->freq) + return false; + } + + return (!attr->freq && !opts->freq); +} + /* * The enable_on_exec/disabled value strategy: * @@ -1133,6 +1191,9 @@ void evsel__config(struct evsel *evsel, struct record= _opts *opts, int track =3D evsel->tracking; bool per_cpu =3D opts->target.default_per_cpu && !opts->target.per_thread; =20 + bool allow_inherit_stat_sample_read =3D evsel__compat_with_inherit_sample= _read( + opts, leader, evsel); + attr->sample_id_all =3D perf_missing_features.sample_id_all ? 0 : 1; attr->inherit =3D !opts->no_inherit; attr->write_backward =3D opts->overwrite ? 1 : 0; @@ -1156,7 +1217,17 @@ void evsel__config(struct evsel *evsel, struct recor= d_opts *opts, */ if (leader->core.nr_members > 1) { attr->read_format |=3D PERF_FORMAT_GROUP; - attr->inherit =3D 0; + if (!allow_inherit_stat_sample_read) + attr->inherit =3D 0; + } + + /* + * Inherit + READ requires inherit_stat, but only if freq is + * not set as the two are incompatible + */ + if (attr->inherit && allow_inherit_stat_sample_read) { + attr->inherit_stat =3D 1; + evsel__set_sample_bit(evsel, TID); } } =20 @@ -1832,6 +1903,8 @@ 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.inherit_sample_read) + evsel->core.attr.inherit =3D 0; if (perf_missing_features.branch_counters) evsel->core.attr.branch_sample_type &=3D ~PERF_SAMPLE_BRANCH_COUNTERS; if (perf_missing_features.read_lost) @@ -1887,7 +1960,12 @@ bool evsel__detect_missing_features(struct evsel *ev= sel) * Must probe features in the order they were added to the * perf_event_attr interface. */ - if (!perf_missing_features.branch_counters && + if (!perf_missing_features.inherit_sample_read && + evsel->core.attr.inherit && (evsel->core.attr.sample_type & PERF_SAMP= LE_READ)) { + perf_missing_features.inherit_sample_read =3D true; + pr_debug2("Using PERF_SAMPLE_READ / :S modifier is not compatible with i= nherit, falling back to no-inherit.\n"); + return true; + } else if (!perf_missing_features.branch_counters && (evsel->core.attr.branch_sample_type & PERF_SAMPLE_BRANCH_COUNTERS)) { perf_missing_features.branch_counters =3D true; pr_debug2("switching off branch counters support\n"); diff --git a/tools/perf/util/evsel.h b/tools/perf/util/evsel.h index efbb6e848287..11cc9b8bee27 100644 --- a/tools/perf/util/evsel.h +++ b/tools/perf/util/evsel.h @@ -192,6 +192,7 @@ struct perf_missing_features { bool weight_struct; bool read_lost; bool branch_counters; + bool inherit_sample_read; }; =20 extern struct perf_missing_features perf_missing_features; --=20 2.44.0