From patchwork Mon Nov 29 11:07:50 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: 517406 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 EE300C433F5 for ; Mon, 29 Nov 2021 11:11:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1376794AbhK2LPJ convert rfc822-to-8bit (ORCPT ); Mon, 29 Nov 2021 06:15:09 -0500 Received: from us-smtp-delivery-44.mimecast.com ([207.211.30.44]:58908 "EHLO us-smtp-delivery-44.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232126AbhK2LNH (ORCPT ); Mon, 29 Nov 2021 06:13:07 -0500 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-563-M80VWAF8MjutGVkCMBk1KA-1; Mon, 29 Nov 2021 06:09:44 -0500 X-MC-Unique: M80VWAF8MjutGVkCMBk1KA-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 09FCF835B4B; Mon, 29 Nov 2021 11:09:42 +0000 (UTC) Received: from x1.com (unknown [10.22.8.188]) by smtp.corp.redhat.com (Postfix) with ESMTP id 89CF85D9DE; Mon, 29 Nov 2021 11:09:36 +0000 (UTC) From: Daniel Bristot de Oliveira To: Steven Rostedt Cc: Tao Zhou , Daniel Bristot de Oliveira , Ingo Molnar , Tom Zanussi , Masami Hiramatsu , Juri Lelli , Clark Williams , John Kacur , 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: [PATCH V8 12/14] rtla: Add rtla timerlat documentation Date: Mon, 29 Nov 2021 12:07:50 +0100 Message-Id: <644599d0041c53a2d0646ca72eaa783100dc32a2.1638182284.git.bristot@kernel.org> 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-rt-users@vger.kernel.org Man page for rtla timerlat tool. Cc: Steven Rostedt Cc: Ingo Molnar Cc: Tom Zanussi Cc: Masami Hiramatsu Cc: Juri Lelli Cc: Clark Williams Cc: John Kacur 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/common_timerlat_description.rst | 10 ++++ Documentation/tools/rtla/rtla-timerlat.rst | 57 +++++++++++++++++++ 2 files changed, 67 insertions(+) create mode 100644 Documentation/tools/rtla/common_timerlat_description.rst create mode 100644 Documentation/tools/rtla/rtla-timerlat.rst diff --git a/Documentation/tools/rtla/common_timerlat_description.rst b/Documentation/tools/rtla/common_timerlat_description.rst new file mode 100644 index 000000000000..321201cb8597 --- /dev/null +++ b/Documentation/tools/rtla/common_timerlat_description.rst @@ -0,0 +1,10 @@ +The **rtla timerlat** tool is an interface for the *timerlat* tracer. The +*timerlat* tracer dispatches a kernel thread per-cpu. These threads +set a periodic timer to wake themselves up and go back to sleep. After +the wakeup, they collect and generate useful information for the +debugging of operating system timer latency. + +The *timerlat* tracer outputs information in two ways. It periodically +prints the timer latency at the timer *IRQ* handler and the *Thread* +handler. It also enable the trace of the most relevant information via +**osnoise:** tracepoints. diff --git a/Documentation/tools/rtla/rtla-timerlat.rst b/Documentation/tools/rtla/rtla-timerlat.rst new file mode 100644 index 000000000000..44a49e6f302b --- /dev/null +++ b/Documentation/tools/rtla/rtla-timerlat.rst @@ -0,0 +1,57 @@ +================ +rtla-timerlat +================ +------------------------------------------- +Measures the operating system timer latency +------------------------------------------- + +:Manual section: 1 + +SYNOPSIS +======== +**rtla timerlat** [*MODE*] ... + +DESCRIPTION +=========== + +.. include:: common_timerlat_description.rst + +The *timerlat* tracer outputs information in two ways. It periodically +prints the timer latency at the timer *IRQ* handler and the *Thread* handler. +It also provides information for each noise via the **osnoise:** tracepoints. +The **rtla timerlat top** mode displays a summary of the periodic output +from the *timerlat* tracer. The **rtla hist hist** mode displays a histogram +of each tracer event occurrence. For further details, please refer to the +respective man page. + +MODES +===== +**top** + + Prints the summary from *timerlat* tracer. + +**hist** + + Prints a histogram of timerlat samples. + +If no *MODE* is given, the top mode is called, passing the arguments. + +OPTIONS +======= +**-h**, **--help** + + Display the help text. + +For other options, see the man page for the corresponding mode. + +SEE ALSO +======== +**rtla-timerlat-top**\(1), **rtla-timerlat-hist**\(1) + +*timerlat* tracer documentation: + +AUTHOR +====== +Written by Daniel Bristot de Oliveira + +.. include:: common_appendix.rst