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 5D159C636D6 for ; Wed, 22 Feb 2023 18:06:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232348AbjBVSGl (ORCPT ); Wed, 22 Feb 2023 13:06:41 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46166 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232356AbjBVSGi (ORCPT ); Wed, 22 Feb 2023 13:06:38 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 76C4C41B56 for ; Wed, 22 Feb 2023 10:06:35 -0800 (PST) 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 ams.source.kernel.org (Postfix) with ESMTPS id 19CE1B811EC for ; Wed, 22 Feb 2023 18:06:34 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id D348AC433EF; Wed, 22 Feb 2023 18:06:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677089192; bh=NneJ94Y3qrva9WMEfB+ceVwe9eTBrW4xkQPNf+7x1tU=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=LtxkcGhQuIYNXxq4Uc9fCRvmpnkcREP/FVlC01COVnl6YIYfIE93/VSU+X4kYksI5 SAHDzVItDFrlSRInbpIdvU+n5q84iwh8MTIKZcYdlBBbDeT+LzQFVdwleK7SM9Tayb Fp/l77Gd69UOLYC6ksJDim1mhQGfPXFZCWz4YSm4hVjG90pEIrUVANS52FwAk59TcD +cMdLJf0wUOlqo/VPTFvfgWcS4H28DI+Ik1bMHiBpUyR7krj0fwrvjBqlfnFFVN7rm BV2cSeWMW+PTyiqp04GsJEiomA334/kL69yy1YB3HOdbxldn9hVVzuPR0aKPv0pnlp Si4ZIv3uX2npw== Message-ID: <38c56e37-2805-0b93-57f6-a176e4eb98f6@kernel.org> Date: Wed, 22 Feb 2023 15:06:29 -0300 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Subject: Re: About rtla osnoise and timerlat usage To: Prasad Pandit Cc: linux-trace-users@vger.kernel.org References: <8ae9144f-6d7c-2b63-4fe7-4f124b5515bf@kernel.org> Content-Language: en-US From: Daniel Bristot de Oliveira In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-users@vger.kernel.org On 2/22/23 09:39, Prasad Pandit wrote: > Hello Daniel, > > Thank you so much for your reply, I appreciate it. > > On Wed, 22 Feb 2023 at 17:30, Daniel Bristot de Oliveira > wrote: > > This is the timerlat's timer, so it is expected. What this trace is pointing is to > a possible exit from idle latency... so idle tune is required for this system > and *this metric*... but > > > * Idle tune? ops, I did not reply to this: idle tuning is configuring the system to avoid deep idle states. An easy way to do it is either setting idle=poll or enabling the "--dma-latency 0" in timerlat. But this is only a "problem" for timerlat/cyclictest, not for oslat/osnoise as they measure the noise as they run - so they CPU does not go idle. > > Yes, that is expected on timerlat in an isolated CPU. But not with osnoise/oslat kind of tool, > as they keep running, while timerlat/cyclictest go to sleep. > > > * I see, okay. > > Let me know how rtla osnoise results are, so I can help more.  > > > * Yes, I've been running oslat(1) and rtla-osnoise(1) too. >    Please see: >     oslat(1) log -> https://0bin.net/paste/T0PDXHz5#AnNEzkTRxQVT1gvAqKM43jW+yhqilbNbFqHIHHpy4MY >     rtla-osnoise-top(1) log -> https://0bin.net/paste/8qwjebnZ#22sfTYTv68JAAMHZJhnCBTP-uvP7Mxj8ipAVbuQVsiy > > Thank you. > --- >   - P J P