From patchwork Fri Sep 17 15:43:59 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Bristot de Oliveira X-Patchwork-Id: 12502691 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=-14.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 88AB6C433EF for ; Fri, 17 Sep 2021 15:47:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 716A061279 for ; Fri, 17 Sep 2021 15:47:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243822AbhIQPso convert rfc822-to-8bit (ORCPT ); Fri, 17 Sep 2021 11:48:44 -0400 Received: from us-smtp-delivery-44.mimecast.com ([205.139.111.44]:48987 "EHLO us-smtp-delivery-44.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343536AbhIQPsH (ORCPT ); Fri, 17 Sep 2021 11:48:07 -0400 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-304-I7gHnH5TOGuCnP9Tr-AKZA-1; Fri, 17 Sep 2021 11:46:41 -0400 X-MC-Unique: I7gHnH5TOGuCnP9Tr-AKZA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4968B192376A; Fri, 17 Sep 2021 15:46:40 +0000 (UTC) Received: from x1.bristot.me.homenet.telecomitalia.it (unknown [10.22.17.200]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6A0CA5D9C6; Fri, 17 Sep 2021 15:46:37 +0000 (UTC) From: Daniel Bristot de Oliveira To: Steven Rostedt Cc: Jonathan Corbet , Kate Carcia , Daniel Bristot de Oliveira , Ingo Molnar , Tom Zanussi , Masami Hiramatsu , Juri Lelli , Clark Williams , Peter Zijlstra , Thomas Gleixner , Sebastian Andrzej Siewior , linux-rt-users@vger.kernel.org, linux-trace-devel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [RFC 16/19] rtla: Add rtla osnoise hist documentation Date: Fri, 17 Sep 2021 17:43:59 +0200 Message-Id: In-Reply-To: References: MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=bristot@kernel.org X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org Man page for rtla osnoise hist mode. Cc: Steven Rostedt Cc: Ingo Molnar Cc: Tom Zanussi Cc: Masami Hiramatsu Cc: Juri Lelli Cc: Clark Williams Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Sebastian Andrzej Siewior Cc: Daniel Bristot de Oliveira Cc: linux-rt-users@vger.kernel.org Cc: linux-trace-devel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Daniel Bristot de Oliveira --- .../rtla/Documentation/rtla-osnoise-hist.txt | 117 ++++++++++++++++++ 1 file changed, 117 insertions(+) create mode 100644 tools/tracing/rtla/Documentation/rtla-osnoise-hist.txt diff --git a/tools/tracing/rtla/Documentation/rtla-osnoise-hist.txt b/tools/tracing/rtla/Documentation/rtla-osnoise-hist.txt new file mode 100644 index 000000000000..56d98ab10387 --- /dev/null +++ b/tools/tracing/rtla/Documentation/rtla-osnoise-hist.txt @@ -0,0 +1,117 @@ +rtla-osnoise-hist(1) +=================== + +NAME +---- +rtla-osnoise-hist - Display a histogram of the osnoise tracer samples + +SYNOPSIS +-------- +*rtla osnoise hist* ['OPTIONS'] + +DESCRIPTION +----------- +The *rtla-osnoise-hist(1)* tool is an interface for the osnoise tracer. The +osnoise tracer dispatches a kernel thread per-cpu. These threads read the +time in a loop while with preemption, SoftIRQs and IRQs enabled, thus +allowing all the sources of osnoise during its execution. The osnoise threads +take note of the delta between each time read. Anytime the delta between two +consecutive reads of the timer is higher than a 'threshold,' an +*osnoise:sample_threshold* event is generated reporting the detected noise. + +The *rtla-osnoise-hist(1)* tool collects all *osnoise:sample_threshold* +occurrence in a histogram, displaying the results in a user-friendly way. +The tool also allows many configurations of the osnoise tracer and the +collection of the tracer output. + +OPTIONS +------- +*-h*, *--help*:: +Print help menu. +*-p*, *--period* 'us':: +Set the osnoise tracer period in microseconds. +*-r*, *--runtime* 'us':: +Set the osnoise tracer runtime in microseconds. +*-s*, *--stop* 'us':: +Stop the trace if a single sample is higher than the argument in microseconds. +If -T is set, it will also save the trace to the output. +*-S*, *--stop-total* 'us':: +Stop the trace if the total sample is higher than the argument in microseconds. +If -T is set, it will also save the trace to the output. +*-c*, *--cpus* 'cpu-list':: +Set the osnoise tracer to run the sample threads in the cpu-list. +*-d*, *--duration* 'time[s|m|h|d]':: +Set the duration of the session. +*-T*, *--trace*['=file']:: +Save the stopped trace to ['file|osnoise_trace.txt']. +*-P*, *--priority* 'o:prio|r:prio|f:prio|d:runtime:period':: +Set scheduling parameters to the osnoise tracer threads, the format to +set the priority are: + - 'o:prio' - use SCHED_OTHER with 'prio'; + - 'r:prio' - use SCHED_RR with 'prio'; + - 'f:prio' - use SCHED_FIFO with 'prio'; + - 'd:runtime[us|ms|s]:period[us|ms|s]' - use SCHED_DEADLINE with +'runtime' and 'period' in nanoseconds. + +*-b*, --bucket_size 'N':: +Set the histogram bucket size (default 1). +*-e*, --entries 'N':: +Set the number of entries of the histogram (default 256). +*--no-header*:: +Do not print header. +*--no-summary*:: +Do not print summary. +*--no-index*:: +Do not print index. +*--skip-zeros*:: +Skip zero only entries. + +EXAMPLE +------- +In the example below, osnoise tracer threads are set to run with real-time +priority 'FIFO:1', on CPUs '0-11', for '900ms' at each period ('1s' by +default). The reason for reducing the runtime is to avoid starving the rtla +tool. The tool is also set to run for 'one minute.' The output histogram is +set to group outputs in buckets of '10 us' and '25' entries. + +------------------------------------------------------- +[root@f34 ~/]# rtla osnoise hist -P F:1 -c 0-11 -r 900000 -d 1M --skip-zeros -b 10 -e 25 +# RTLA osnoise histogram +# Time unit is microseconds (us) +# Duration: 0 00:01:00 +Index CPU-000 CPU-001 CPU-002 CPU-003 CPU-004 CPU-005 CPU-006 CPU-007 CPU-008 CPU-009 CPU-010 CPU-011 +0 42982 46287 51779 53740 52024 44817 49898 36500 50408 50128 49523 52377 +10 12224 8356 2912 878 2667 10155 4573 18894 4214 4836 5708 2413 +20 8 5 12 2 13 24 20 41 29 53 39 39 +30 1 1 0 0 10 3 6 19 15 31 30 38 +40 0 0 0 0 0 4 2 7 2 3 8 11 +50 0 0 0 0 0 0 0 0 0 1 1 2 +over: 0 0 0 0 0 0 0 0 0 0 0 0 +count: 55215 54649 54703 54620 54714 55003 54499 55461 54668 55052 55309 54880 +min: 0 0 0 0 0 0 0 0 0 0 0 0 +avg: 0 0 0 0 0 0 0 0 0 0 0 0 +max: 30 30 20 20 30 40 40 40 40 50 50 50 +------------------------------------------------------- + +SEE ALSO +-------- +_rtla-osnoise(1)_, _rtla-osnoise-top_(1) + +Osnoise tracer documentation: + +AUTHOR +------ +Written by Daniel Bristot de Oliveira + +REPORTING BUGS +-------------- +Report bugs to + +LICENSE +------- +rtla is Free Software licensed under the GNU GPLv2 + +COPYING +------- +Copyright \(C) 2021 Red Hat, Inc. Free use of this software is granted under +the terms of the GNU Public License (GPL).