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 X-Spam-Level: X-Spam-Status: No, score=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 596C9C18E00 for ; Wed, 19 Feb 2020 19:10:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C4F62465D for ; Wed, 19 Feb 2020 19:10:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727046AbgBSTKf (ORCPT ); Wed, 19 Feb 2020 14:10:35 -0500 Received: from mga05.intel.com ([192.55.52.43]:7642 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726776AbgBSTKd (ORCPT ); Wed, 19 Feb 2020 14:10:33 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga105.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 19 Feb 2020 11:10:32 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,461,1574150400"; d="scan'208";a="408536207" Received: from otc-lr-04.jf.intel.com ([10.54.39.48]) by orsmga005.jf.intel.com with ESMTP; 19 Feb 2020 11:10:31 -0800 From: kan.liang@linux.intel.com To: acme@kernel.org, jolsa@redhat.com, mingo@redhat.com, peterz@infradead.org, linux-kernel@vger.kernel.org Cc: mark.rutland@arm.com, namhyung@kernel.org, ravi.bangoria@linux.ibm.com, yao.jin@linux.intel.com, ak@linux.intel.com, Kan Liang Subject: [PATCH 3/5] perf util: Factor out sysctl__nmi_watchdog_enabled() Date: Wed, 19 Feb 2020 11:08:38 -0800 Message-Id: <1582139320-75181-4-git-send-email-kan.liang@linux.intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1582139320-75181-1-git-send-email-kan.liang@linux.intel.com> References: <1582139320-75181-1-git-send-email-kan.liang@linux.intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Kan Liang NMI watchdog status is required for metric group constraint examination. Factor out sysctl__nmi_watchdog_enabled() to retrieve the NMI watchdog status. Users may count more than one metric groups each time. If so, the NMI watchdog status may be retrieved several times. To reduce the overhead, cache the NMI watchdog status. Replace the NMI watchdog status checking in print_footer() by sysctl__nmi_watchdog_enabled(). Suggested-by: Andi Kleen Signed-off-by: Kan Liang --- tools/perf/util/stat-display.c | 6 ++---- tools/perf/util/util.c | 18 ++++++++++++++++++ tools/perf/util/util.h | 2 ++ 3 files changed, 22 insertions(+), 4 deletions(-) diff --git a/tools/perf/util/stat-display.c b/tools/perf/util/stat-display.c index bc31fcc..16efdba 100644 --- a/tools/perf/util/stat-display.c +++ b/tools/perf/util/stat-display.c @@ -16,6 +16,7 @@ #include #include "cgroup.h" #include +#include "util.h" #define CNTR_NOT_SUPPORTED "" #define CNTR_NOT_COUNTED "" @@ -1097,7 +1098,6 @@ static void print_footer(struct perf_stat_config *config) { double avg = avg_stats(config->walltime_nsecs_stats) / NSEC_PER_SEC; FILE *output = config->output; - int n; if (!config->null_run) fprintf(output, "\n"); @@ -1131,9 +1131,7 @@ static void print_footer(struct perf_stat_config *config) } fprintf(output, "\n\n"); - if (config->print_free_counters_hint && - sysctl__read_int("kernel/nmi_watchdog", &n) >= 0 && - n > 0) + if (config->print_free_counters_hint && sysctl__nmi_watchdog_enabled()) fprintf(output, "Some events weren't counted. Try disabling the NMI watchdog:\n" " echo 0 > /proc/sys/kernel/nmi_watchdog\n" diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c index 969ae56..d707c96 100644 --- a/tools/perf/util/util.c +++ b/tools/perf/util/util.c @@ -55,6 +55,24 @@ int sysctl__max_stack(void) return sysctl_perf_event_max_stack; } +bool sysctl__nmi_watchdog_enabled(void) +{ + static bool cached; + static bool nmi_watchdog; + int value; + + if (cached) + return nmi_watchdog; + + if (sysctl__read_int("kernel/nmi_watchdog", &value) < 0) + return false; + + nmi_watchdog = (value > 0) ? true : false; + cached = true; + + return nmi_watchdog; +} + bool test_attr__enabled; bool perf_host = true; diff --git a/tools/perf/util/util.h b/tools/perf/util/util.h index 9969b8b..f486fdd 100644 --- a/tools/perf/util/util.h +++ b/tools/perf/util/util.h @@ -29,6 +29,8 @@ size_t hex_width(u64 v); int sysctl__max_stack(void); +bool sysctl__nmi_watchdog_enabled(void); + int fetch_kernel_version(unsigned int *puint, char *str, size_t str_sz); #define KVER_VERSION(x) (((x) >> 16) & 0xff) -- 2.7.4