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[209.132.180.67]) by mx.google.com with ESMTP id b3-v6si779174plc.309.2018.02.16.21.51.17; Fri, 16 Feb 2018 21:52:14 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751255AbeBQFtb (ORCPT + 99 others); Sat, 17 Feb 2018 00:49:31 -0500 Received: from mga02.intel.com ([134.134.136.20]:59982 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751133AbeBQFt0 (ORCPT ); Sat, 17 Feb 2018 00:49:26 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 16 Feb 2018 21:49:26 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.46,523,1511856000"; d="scan'208";a="20863414" Received: from gvt-dell.bj.intel.com (HELO gvt-dell-host.bj.intel.com) ([10.238.154.59]) by fmsmga002.fm.intel.com with ESMTP; 16 Feb 2018 21:49:25 -0800 From: changbin.du@intel.com To: corbet@lwn.net, rostedt@goodmis.org Cc: mingo@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, Changbin Du Subject: [PATCH 15/17] trace doc: convert trace/hwlat_detector.txt to rst fromat Date: Sat, 17 Feb 2018 13:39:48 +0800 Message-Id: <1518845990-20733-16-git-send-email-changbin.du@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1518845990-20733-1-git-send-email-changbin.du@intel.com> References: <1518845990-20733-1-git-send-email-changbin.du@intel.com> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Changbin Du This converts the plain text documentation to reStructuredText format and add it into Sphinx TOC tree. No essential content change. Cc: Steven Rostedt Signed-off-by: Changbin Du --- .../{hwlat_detector.txt => hwlat_detector.rst} | 26 +++++++++++++--------- Documentation/trace/index.rst | 1 + 2 files changed, 16 insertions(+), 11 deletions(-) rename Documentation/trace/{hwlat_detector.txt => hwlat_detector.rst} (83%) diff --git a/Documentation/trace/hwlat_detector.txt b/Documentation/trace/hwlat_detector.rst similarity index 83% rename from Documentation/trace/hwlat_detector.txt rename to Documentation/trace/hwlat_detector.rst index 3207717..5739349 100644 --- a/Documentation/trace/hwlat_detector.txt +++ b/Documentation/trace/hwlat_detector.rst @@ -1,4 +1,8 @@ -Introduction: +========================= +Hardware Latency Detector +========================= + +Introduction ------------- The tracer hwlat_detector is a special purpose tracer that is used to @@ -28,7 +32,7 @@ Note that the hwlat detector should *NEVER* be used in a production environment. It is intended to be run manually to determine if the hardware platform has a problem with long system firmware service routines. -Usage: +Usage ------ Write the ASCII text "hwlat" into the current_tracer file of the tracing system @@ -36,16 +40,16 @@ Write the ASCII text "hwlat" into the current_tracer file of the tracing system redefine the threshold in microseconds (us) above which latency spikes will be taken into account. -Example: +Example:: # echo hwlat > /sys/kernel/tracing/current_tracer # echo 100 > /sys/kernel/tracing/tracing_thresh The /sys/kernel/tracing/hwlat_detector interface contains the following files: -width - time period to sample with CPUs held (usecs) - must be less than the total window size (enforced) -window - total period of sampling, width being inside (usecs) + - width - time period to sample with CPUs held (usecs) + must be less than the total window size (enforced) + - window - total period of sampling, width being inside (usecs) By default the width is set to 500,000 and window to 1,000,000, meaning that for every 1,000,000 usecs (1s) the hwlat detector will spin for 500,000 usecs @@ -67,11 +71,11 @@ The following tracing directory files are used by the hwlat_detector: in /sys/kernel/tracing: - tracing_threshold - minimum latency value to be considered (usecs) - tracing_max_latency - maximum hardware latency actually observed (usecs) - tracing_cpumask - the CPUs to move the hwlat thread across - hwlat_detector/width - specified amount of time to spin within window (usecs) - hwlat_detector/window - amount of time between (width) runs (usecs) + - tracing_threshold - minimum latency value to be considered (usecs) + - tracing_max_latency - maximum hardware latency actually observed (usecs) + - tracing_cpumask - the CPUs to move the hwlat thread across + - hwlat_detector/width - specified amount of time to spin within window (usecs) + - hwlat_detector/window - amount of time between (width) runs (usecs) The hwlat detector's kernel thread will migrate across each CPU specified in tracing_cpumask between each window. To limit the migration, either modify diff --git a/Documentation/trace/index.rst b/Documentation/trace/index.rst index 4b3d690..eabbbaf 100644 --- a/Documentation/trace/index.rst +++ b/Documentation/trace/index.rst @@ -18,3 +18,4 @@ Linux Tracing Technologies events-nmi events-msr mmiotrace + hwlat_detector -- 2.7.4