From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-dl1-f74.google.com (mail-dl1-f74.google.com [74.125.82.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 585EF48AE2D for ; Thu, 4 Jun 2026 16:36:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.82.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780590996; cv=none; b=q93Iz01t35Ku1zrakHBMvLyKynDX6YheuetUACvfrzrzpLoo1AIWlnSfm2e7KaZIXV5VxYuweg+beeKOEnmiYjpK0Ytvtqm1TJv1a99g/5oXYUrCsrf4rW0IAQcEshLixsZ6i9uMesr/YlVgZL+deoFTWDp1HKaCLba3CimIXtQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780590996; c=relaxed/simple; bh=S//dvOBs/USieF1vXWpNPbPuhuIfEQr4R8jo7tO7zf4=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=U7SikoumeI9IAa/GR054N+puoMGKexPbEYIFC9Yr3Bp7hQM2fWcEV3GT1Dm6D0re6LwTNSw61P3gqAQce8yNur0XF7Hw33Dc1kAF6cBeRA6nFDNp0X0jB6XVTMJujoJGodcrLLD/dw+Gll+98ieIA7mTq0x2Y9DZjy6IsijIYfM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=a6gPaQVH; arc=none smtp.client-ip=74.125.82.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--irogers.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="a6gPaQVH" Received: by mail-dl1-f74.google.com with SMTP id a92af1059eb24-135916eefa0so103832c88.1 for ; Thu, 04 Jun 2026 09:36:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1780590994; x=1781195794; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=XCZcSKYNKaSrihd7vUWodA5r8ht64vt3LOLPQyq/or8=; b=a6gPaQVHjCeyo9/RLk3DGy+MujCzdCUkpQGtfpEJ7tMZN6zYl7t9Rkk9tADgW5ZNmn BL/AsKhp1gh67wk45DGbWxfv8ld3sVsgBAT+h5a6QNJie4vB9eVR/viq4wMf4ykfQo2n j+7m4PMhOzkH8t/SFTOSIqf4shidtl+OyzFM7K41djiHwPlrdBMAqUMeQj/jEunUY/Je bH3iZQC+eK2Cy3yJU+8H3kKnANm2L7PDY6wtwEED6K5kIkkptOh14P0IIPYx+Ecd2cIx uN7lAnW7r4HFKQ8slByFqxQpLFgjEmqCcYMB6nDLs7sTjwAY0WiV/UzmCYoaXYy6k4JH HgIw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1780590994; x=1781195794; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=XCZcSKYNKaSrihd7vUWodA5r8ht64vt3LOLPQyq/or8=; b=RS7ygtIg+d7jNLhJ7ltxWBqf7ddixrY7O+oEMGp0cPsH5aGflDpSNfT7iv7Ii30Q5I 3olnZMVIgJ9Z0T2ddoXp068UJzaQ+zRwt/QpY3sQTNOgWcj6MRdpLB4EXqUwhE4qgA18 94bNisXpgUti81Y1Qh8g90kNukHogoKG0ttfZTtlwD0D5rqj4zyo/Axs/wKDVgYEvkFp NfwmCEuBd9+lY11wijnMHBC4bf7Bo/R22u6lgRaIOa60cAHM39prcB//V2fW8/NUrMwU z+JhrHEZrtMkGbv6mW9tnhso7zDp/fPeXuYV1uI5nbg8g9XGVil0IvFdn8sTdK729jeh afyw== X-Forwarded-Encrypted: i=1; AFNElJ+HzT3tLPcy6lkKs9G/UETvvQhQFMXRxGRQk11WcGFev4lGmDKq8lgCY2e8g0i5bi8XxVBUjiCboW41P5k=@vger.kernel.org X-Gm-Message-State: AOJu0YzmeXukmqOvqARA/rHbHTz00HDFF1bprb0Ry/y+NBRKZLYO7L8U //wHhKRL8dEfgvmxlN0Hu9Ow+ZHmuK9yNKWQjXi9Wb6/7HeyufAMhb4TaGEOZ+/JPBIoV/52Ldu xWKy5jwW65A== X-Received: from dlbep4.prod.google.com ([2002:a05:7022:1084:b0:132:d312:88dc]) (user=irogers job=prod-delivery.src-stubby-dispatcher) by 2002:a05:701a:c951:b0:137:fb3f:8b65 with SMTP id a92af1059eb24-137fb3f8e2dmr3326779c88.10.1780590994051; Thu, 04 Jun 2026 09:36:34 -0700 (PDT) Date: Thu, 4 Jun 2026 09:36:26 -0700 In-Reply-To: <20260604163627.501078-1-irogers@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260602174129.3192312-1-irogers@google.com> <20260604163627.501078-1-irogers@google.com> X-Mailer: git-send-email 2.54.0.1032.g2f8565e1d1-goog Message-ID: <20260604163627.501078-2-irogers@google.com> Subject: [PATCH v9 1/2] perf pmu: Recognize 'default_core' as a core PMU and document matching From: Ian Rogers To: irogers@google.com Cc: acme@kernel.org, adrian.hunter@intel.com, alexander.shishkin@linux.intel.com, james.clark@linaro.org, jolsa@kernel.org, linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, mingo@redhat.com, namhyung@kernel.org, peterz@infradead.org Content-Type: text/plain; charset="UTF-8" The is_pmu_core function checks if a PMU name corresponds to a core CPU PMU. However, it currently fails to recognize "default_core" as a core PMU. When "default_core" is used, the PMU scanning fallback in pmus.c scans the "other_pmus" list. This scan is slow and always misses because "default_core" is a core PMU, leading to unnecessary overhead. Update is_pmu_core to recognize "default_core" directly. Additionally, document the different matching approaches (exact name for x86/s390, sysfs-based cpus file check for ARM/hybrid) to clarify how core PMUs are classified. Also, explicitly treat "default_core" as `all_pmus` in `setup_metric_events()` to preserve the original metric resolution behavior for this pseudo-PMU. Assisted-by: Gemini-CLI:Google Gemini 3.1 Pro Signed-off-by: Ian Rogers --- tools/perf/util/metricgroup.c | 3 ++- tools/perf/util/pmu.c | 19 ++++++++++++++++++- 2 files changed, 20 insertions(+), 2 deletions(-) diff --git a/tools/perf/util/metricgroup.c b/tools/perf/util/metricgroup.c index 5a489e97c413..c2ce3e53aaee 100644 --- a/tools/perf/util/metricgroup.c +++ b/tools/perf/util/metricgroup.c @@ -295,7 +295,8 @@ static int setup_metric_events(const char *pmu, struct hashmap *ids, const char *metric_id; struct evsel *ev; size_t ids_size, matched_events, i; - bool all_pmus = !strcmp(pmu, "all") || perf_pmus__num_core_pmus() == 1 || !is_pmu_core(pmu); + bool all_pmus = !strcmp(pmu, "all") || !strcmp(pmu, "default_core") || + perf_pmus__num_core_pmus() == 1 || !is_pmu_core(pmu); *out_metric_events = NULL; ids_size = hashmap__size(ids); diff --git a/tools/perf/util/pmu.c b/tools/perf/util/pmu.c index 23337d2fa281..9994709ef12b 100644 --- a/tools/perf/util/pmu.c +++ b/tools/perf/util/pmu.c @@ -2029,9 +2029,26 @@ int perf_pmu__for_each_format(struct perf_pmu *pmu, void *state, pmu_format_call return 0; } +/** + * is_pmu_core() - Check if the given PMU name corresponds to a core CPU PMU. + * @name: The PMU name to check. + * + * Core PMUs can be identified by: + * 1. Exact name match: + * - "cpu": Typically used on x86 architectures. + * - "cpum_cf": Typically used on s390 architectures (CPU Measurement Counter Facility). + * - "default_core": A generic name used to refer to the default core PMU. + * 2. Sysfs file existence check (is_sysfs_pmu_core): + * - Typically used on ARM systems or Intel hybrid architectures (e.g., "cpu_atom", + * "cpu_core"). This approach checks if the sysfs directory for the PMU + * contains a "cpus" file. + */ bool is_pmu_core(const char *name) { - return !strcmp(name, "cpu") || !strcmp(name, "cpum_cf") || is_sysfs_pmu_core(name); + return !strcmp(name, "cpu") || + !strcmp(name, "cpum_cf") || + !strcmp(name, "default_core") || + is_sysfs_pmu_core(name); } bool perf_pmu__supports_legacy_cache(const struct perf_pmu *pmu) -- 2.54.0.1032.g2f8565e1d1-goog