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 2975CC6FD1D for ; Mon, 27 Mar 2023 15:27:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232282AbjC0P1a (ORCPT ); Mon, 27 Mar 2023 11:27:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43478 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230187AbjC0P1Z (ORCPT ); Mon, 27 Mar 2023 11:27:25 -0400 Received: from sin.source.kernel.org (sin.source.kernel.org [IPv6:2604:1380:40e1:4800::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E279230C0 for ; Mon, 27 Mar 2023 08:27:23 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sin.source.kernel.org (Postfix) with ESMTPS id 0D4E8CE17B9 for ; Mon, 27 Mar 2023 15:27:22 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A656EC433D2; Mon, 27 Mar 2023 15:27:19 +0000 (UTC) Date: Mon, 27 Mar 2023 11:27:15 -0400 From: Steven Rostedt To: Daniel Bristot de Oliveira Cc: Masami Hiramatsu , Tom Zanussi , LKML Subject: Re: Enable histograms for events/ftrace/timerlat and osnoise Message-ID: <20230327112715.023a94fd@gandalf.local.home> In-Reply-To: <9a1bb631-587c-9771-99b7-55623c67bb83@redhat.com> References: <9a1bb631-587c-9771-99b7-55623c67bb83@redhat.com> X-Mailer: Claws Mail 3.17.8 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 27 Mar 2023 14:37:11 +0200 Daniel Bristot de Oliveira wrote: > On 3/24/23 17:13, Daniel Bristot de Oliveira wrote: > > Hi Steven > > > > I would like to collect histograms from timerlat and osnoise tracers event, > > but I cannot collect them because they are not tracepoints but... tracer > > events. So... > > > > # ls /sys/kernel/tracing/events/ftrace/timerlat/ > > format hist > > > > no hist, filter, trigger files... > > Ooop, the hist file exists, what is missing is the trigger file, which is > used to enable the histogram... > > it seems that the "limitation" is around TRACE_EVENT_FL_IGNORE_ENABLE flag, and > the fact that ftrace events cannot be enabled/disabled... > > but wait, as the hist file exist, is there any other way to enable > the histogram? (or should we disable hist files for !TRACE_EVENT_FL_IGNORE_ENABLE)? No, I think we just missed not creating the "hist" file, which should not actually exist. > > am I missing something? > > > How hard would it be to enable histograms to the ftrace/osnoise and > > ftrace/timerlat events? I'll try to get some time to look at this. No guarantees :-p -- Steve > > > > This will allow me to reduce the overhead of rtla timerlat and rtla osnoise > > tools... > > > > Thanks in advance, Stephen! > > -- Denny