From mboxrd@z Thu Jan 1 00:00:00 1970 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 CC6B3C433F5 for ; Fri, 27 May 2022 04:04:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239002AbiE0EEQ (ORCPT ); Fri, 27 May 2022 00:04:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239923AbiE0EEP (ORCPT ); Fri, 27 May 2022 00:04:15 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 73418EBEBF for ; Thu, 26 May 2022 21:04:12 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id 4-20020a251004000000b0064df0151b18so3156401ybq.21 for ; Thu, 26 May 2022 21:04:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:message-id:mime-version:subject:from:to:cc; bh=j18U4kkoV3/OvD/NxmpbujJMFVrALYJLqrC/u8afB3Y=; b=rYOMuXfxQ0JMU55WylL/alxBXhjaeUWA5X7tZBAwe9tOtz2AOZ8KCHRjhZ705+9yQ2 Y+P9oC528jBkB8vZ9rFzUMutNg8Bm1yGLd8zW0F28KxsbNb6ArmoFwQphF2i+SEMjpWB lTbAlyf6Oysye0qwhGrWi0W0NJEaFIBU150aTjyubMivPjBYzefYIZ+92QPbBbUm01jD w2sEMPIaiYQpejOqYrCQkH2cHeULS4Ieyp4gXI0NUjzwA0vBETe3VCPkQXIN0lpjrQWg Fg3gm8newNcfcniJ76t4WcX1SuDEQF4HefnhqXmiDpQuuiDqF6tk+a6uVU7xUM4LR2W/ 3OaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=j18U4kkoV3/OvD/NxmpbujJMFVrALYJLqrC/u8afB3Y=; b=Dn0PXLXFmJp5qkBowS18D+S6Vc39nRZIgXxKetwiKNeZlpBnx5iJPK/3rywBXyGgbL 1lwIDV3XYg1Z6gTYvUcb2lZCNSSZYxEa77a6c/hDv1zUvxM0IFuotZ24EMLdtLJ1VyGU L9cnXSwUt/iXwozT181tP5l5QC1LCrcgZ32ZLzgFE3+Py+7dpxMnIURHpaGPFSLeI+Jy 6xe0LGDUVQiWGRZGI4q6uEdb5/LvfGmku274YCjxZ5wTFEHxe9F37iPaBGB46jE//bQ4 FGt/iWXfJDrlwOjmQHjY9JxCYWCmnnJI+wY8NUANcrioBq+RoMeJo/VHSDFLasuNs8ee 3FpQ== X-Gm-Message-State: AOAM530G54vnNbrax1T3DMrtnakIoa2OBUgh6MHj11gFYreG9F5IQjUl 8KB2n3iWB2QbJ+4XOqroqEmr/n+Y6N9Y X-Google-Smtp-Source: ABdhPJxiKaIsaMY5drcO/BtwaU7AIZX/u+pgXW+4vC6FrTrFesrwAr2lSAr2/eRT+aIiaTg2K6xJv/M3KFEl X-Received: from irogers.svl.corp.google.com ([2620:15c:2cd:202:4b39:e167:e698:7d4]) (user=irogers job=sendgmr) by 2002:a0d:d003:0:b0:2eb:6441:d9a3 with SMTP id s3-20020a0dd003000000b002eb6441d9a3mr41096784ywd.273.1653624251555; Thu, 26 May 2022 21:04:11 -0700 (PDT) Date: Thu, 26 May 2022 21:04:07 -0700 Message-Id: <20220527040407.4193232-1-irogers@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.36.1.124.g0e6072fb45-goog Subject: [PATCH v2] perf metrics: Add literal for system TSC frequency From: Ian Rogers To: perry.taylor@intel.com, caleb.biggers@intel.com, kshipra.bopardikar@intel.com, Kan Liang , Zhengjun Xing , Peter Zijlstra , Ingo Molnar , Arnaldo Carvalho de Melo , Mark Rutland , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Maxime Coquelin , Alexandre Torgue , Andi Kleen , James Clark , John Garry , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org Cc: Stephane Eranian , Ian Rogers Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-perf-users@vger.kernel.org Such a literal is useful to calculate things like the average frequency [1]. The TSC frequency isn't exposed by sysfs although some experimental drivers look to add it [2]. This change computes the value using the frequency in /proc/cpuinfo which is accurate at least on Intel processors. v2. Adds warnings to make clear if things have changed/broken on future Intel platforms. It also adds caching and an Intel specific that a value is computed. [1] https://github.com/intel/perfmon-metrics/blob/5ad9ef7056f31075e8178b9f1fb732af183b2c8d/SKX/metrics/perf/skx_metric_perf.json#L11 [2] https://github.com/trailofbits/tsc_freq_khz Signed-off-by: Ian Rogers --- tools/perf/tests/expr.c | 15 +++++++++++++ tools/perf/util/expr.c | 50 +++++++++++++++++++++++++++++++++++++++++ 2 files changed, 65 insertions(+) diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c index 5c0032fe93ae..45afe4f24859 100644 --- a/tools/perf/tests/expr.c +++ b/tools/perf/tests/expr.c @@ -1,8 +1,10 @@ // SPDX-License-Identifier: GPL-2.0 #include "util/debug.h" #include "util/expr.h" +#include "util/header.h" #include "util/smt.h" #include "tests.h" +#include #include #include #include @@ -69,6 +71,11 @@ static int test__expr(struct test_suite *t __maybe_unused, int subtest __maybe_u double val, num_cpus, num_cores, num_dies, num_packages; int ret; struct expr_parse_ctx *ctx; + bool is_intel = false; + char buf[128]; + + if (!get_cpuid(buf, sizeof(buf))) + is_intel = strstr(buf, "Intel") != NULL; TEST_ASSERT_EQUAL("ids_union", test_ids_union(), 0); @@ -175,6 +182,14 @@ static int test__expr(struct test_suite *t __maybe_unused, int subtest __maybe_u if (num_dies) // Some platforms do not have CPU die support, for example s390 TEST_ASSERT_VAL("#num_dies >= #num_packages", num_dies >= num_packages); + if (is_intel) { + double system_tsc_freq; + + TEST_ASSERT_VAL("#system_tsc_freq", expr__parse(&system_tsc_freq, ctx, + "#system_tsc_freq") == 0); + TEST_ASSERT_VAL("!isnan(#system_tsc_freq)", !isnan(system_tsc_freq)); + } + /* * Source count returns the number of events aggregating in a leader * event including the leader. Check parsing yields an id. diff --git a/tools/perf/util/expr.c b/tools/perf/util/expr.c index 675f318ce7c1..f33aeb1e6faa 100644 --- a/tools/perf/util/expr.c +++ b/tools/perf/util/expr.c @@ -402,6 +402,51 @@ double expr_id_data__source_count(const struct expr_id_data *data) return data->val.source_count; } +/* + * Derive the TSC frequency in Hz from the /proc/cpuinfo, for example: + * ... + * model name : Intel(R) Xeon(R) Gold 6154 CPU @ 3.00GHz + * ... + * will return 3000000000. + */ +static double system_tsc_freq(void) +{ + static double result; + static bool computed; + FILE *cpuinfo; + char *line = NULL; + size_t len = 0; + + if (computed) + return result; + + computed = true; + result = NAN; + cpuinfo = fopen("/proc/cpuinfo", "r"); + if (!cpuinfo) { + pr_err("Failed to read /proc/cpuinfo for TSC frequency"); + return NAN; + } + while (getline(&line, &len, cpuinfo) > 0) { + if (!strncmp(line, "model name", 10)) { + char *pos = strstr(line + 11, " @ "); + + if (pos && sscanf(pos, " @ %lfGHz", &result) == 1) { + result *= 1000000000; + goto out; + } + } + } + +out: + if (isnan(result)) + pr_err("Failed to find TSC frequency in /proc/cpuinfo"); + + free(line); + fclose(cpuinfo); + return result; +} + double expr__get_literal(const char *literal) { static struct cpu_topology *topology; @@ -417,6 +462,11 @@ double expr__get_literal(const char *literal) goto out; } + if (!strcasecmp("#system_tsc_freq", literal)) { + result = system_tsc_freq(); + goto out; + } + /* * Assume that topology strings are consistent, such as CPUs "0-1" * wouldn't be listed as "0,1", and so after deduplication the number of -- 2.36.1.124.g0e6072fb45-goog