From nobody Wed Dec 17 08:19:40 2025 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7392B1850B8; Wed, 26 Jun 2024 14:55:27 +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=1719413729; cv=none; b=o1UiRUa9ZcS/EGY9ZfTS6vqJ9BBuNnqdL8LtwqL7UYDMpcbD2xdyuLtJfyslwuQ8GrrDpu/yPmEfGSyBF2hNErd0FVI+d9PAdOoiLTBfmIxTQaPGifb997Unj0C258d7R5BNulRRoXn9JZOfbD8Yt7br0VGidn+2bGE+OqT/xqs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719413729; c=relaxed/simple; bh=KcANrdZ7y8VoQfMbuEJKrubTtZ2yiWBODLZMnaA5OY4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=oKw6RK+Uw4qbh3pRS0bn3VQfCyUuoYLYrCLlQh6Eja94IJWNXSN/w7kpn1KK56wGkdqwRUUdELU5oAUWtRLDQyKDy/y1mbtJVFY+w45iHzHo8gLks0EOZ4DcBoBaqGt0e8dvciPsdU45gx25ZIoy7p3W91jOx6rMeE+F4+gk0ms= 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 C487DDA7; Wed, 26 Jun 2024 07:55:51 -0700 (PDT) Received: from e127643.cambridge.arm.com (e127643.arm.com [10.1.33.71]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 89D703F73B; Wed, 26 Jun 2024 07:55:23 -0700 (PDT) From: James Clark To: linux-perf-users@vger.kernel.org, irogers@google.com, namhyung@kernel.org Cc: robin.murphy@arm.com, James Clark , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Adrian Hunter , "Liang, Kan" , linux-kernel@vger.kernel.org Subject: [PATCH v2 2/2] perf pmu: Don't de-duplicate core PMUs Date: Wed, 26 Jun 2024 15:54:46 +0100 Message-Id: <20240626145448.896746-3-james.clark@arm.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240626145448.896746-1-james.clark@arm.com> References: <20240626145448.896746-1-james.clark@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" Arm PMUs have a suffix, either a single decimal (armv8_pmuv3_0) or 3 hex digits which (armv8_cortex_a53) which Perf assumes are both strippable suffixes for the purposes of deduplication. S390 "cpum_cf" is a similarly suffixed core PMU but is only two characters so is not treated as strippable because the rules are a minimum of 3 hex characters or 1 decimal character. There are two paths involved in listing PMU events: * HW/cache event printing assumes core PMUs don't have suffixes so doesn't try to strip. * Sysfs PMU events share the printing function with uncore PMUs which strips. This results in slightly inconsistent Perf list behavior if a core PMU has a suffix: # perf list ... armv8_pmuv3_0/branch-load-misses/ armv8_pmuv3/l3d_cache_wb/ [Kernel PMU event] ... Fix it by partially reverting back to the old list behavior where stripping was only done for uncore PMUs. For example commit 8d9f5146f5da ("perf pmus: Sort pmus by name then suffix") mentions that only PMUs starting 'uncore_' are considered to have a potential suffix. This change doesn't go back that far, but does only strip PMUs that are !is_core. This keeps the desirable behavior where the many possibly duplicated uncore PMUs aren't repeated, but it doesn't break listing for core PMUs. Searching for a PMU continues to use the new stripped comparison functions, meaning that it's still possible to request an event by specifying the common part of a PMU name, or even open events on multiple similarly named PMUs. For example: # perf stat -e armv8_cortex/inst_retired/ 5777173628 armv8_cortex_a53/inst_retired/ (99.93%) 7469626951 armv8_cortex_a57/inst_retired/ (49.88%) Fixes: 3241d46f5f54 ("perf pmus: Sort/merge/aggregate PMUs like mrvl_ddr_pm= u") Suggested-by: Ian Rogers Signed-off-by: James Clark --- tools/perf/util/pmu.c | 27 +++++++++++++++++++++------ 1 file changed, 21 insertions(+), 6 deletions(-) diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index 97d74fe6d816..28af48ea803f 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -847,6 +847,23 @@ __weak const struct pmu_metrics_table *pmu_metrics_tab= le__find(void) return perf_pmu__find_metrics_table(NULL); } =20 +/** + * Return the length of the PMU name not including the suffix for uncore P= MUs. + * + * We want to deduplicate many similar uncore PMUs by stripping their suff= ixes, + * but there are never going to be too many core PMUs and the suffixes mig= ht be + * interesting. "arm_cortex_a53" vs "arm_cortex_a57" or "cpum_cf" for exam= ple. + * + * @skip_duplicate_pmus: False in verbose mode so all uncore PMUs are visi= ble + */ +static size_t pmu_deduped_name_len(const struct perf_pmu *pmu, const char = *name, + bool skip_duplicate_pmus) +{ + return skip_duplicate_pmus && !pmu->is_core + ? pmu_name_len_no_suffix(name) + : strlen(name); +} + /** * perf_pmu__match_ignoring_suffix - Does the pmu_name match tok ignoring = any * trailing suffix? The Suffix must be i= n form @@ -1796,9 +1813,8 @@ static char *format_alias(char *buf, int len, const s= truct perf_pmu *pmu, const struct perf_pmu_alias *alias, bool skip_duplicate_pmus) { struct parse_events_term *term; - size_t pmu_name_len =3D skip_duplicate_pmus - ? pmu_name_len_no_suffix(pmu->name) - : strlen(pmu->name); + size_t pmu_name_len =3D pmu_deduped_name_len(pmu, pmu->name, + skip_duplicate_pmus); int used =3D snprintf(buf, len, "%.*s/%s", (int)pmu_name_len, pmu->name, = alias->name); =20 list_for_each_entry(term, &alias->terms.terms, list) { @@ -1839,9 +1855,8 @@ int perf_pmu__for_each_event(struct perf_pmu *pmu, bo= ol skip_duplicate_pmus, size_t buf_used, pmu_name_len; =20 info.pmu_name =3D event->pmu_name ?: pmu->name; - pmu_name_len =3D skip_duplicate_pmus - ? pmu_name_len_no_suffix(info.pmu_name) - : strlen(info.pmu_name); + pmu_name_len =3D pmu_deduped_name_len(pmu, info.pmu_name, + skip_duplicate_pmus); info.alias =3D NULL; if (event->desc) { info.name =3D event->name; --=20 2.34.1