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 E7335C7EE25 for ; Wed, 10 May 2023 09:03:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236917AbjEJJDS (ORCPT ); Wed, 10 May 2023 05:03:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54588 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236055AbjEJJDM (ORCPT ); Wed, 10 May 2023 05:03:12 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9ABB93AB6; Wed, 10 May 2023 02:03:11 -0700 (PDT) Date: Wed, 10 May 2023 11:03:07 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1683709388; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=koD4cPNLIm/3wGHC3EUteEyEyTTF+ReaD/tXyekbMOQ=; b=Sj6Q+mZK1Sh7wD3GRIO91IlUZaDPN4ecfDyK/X12c0k+idExcfzk1ObRV8y2qd/iHVhy27 lOx4FLgfQGv0fEm0PiDmkcMQS4iG/W/UzlZHBTu7y7XgZqSDbAsNWbddaAkTvehhFn1I4z lZUsCU1fGAhILvmaR/k3yjMIJ8jg5MddbKXTiV+yIkFhb323++gcq3SIkI9xSSkXXcQs44 3GgJ5KSoEQeIef4I3O7ozG5iaTuDJWs+P6mXyNmaxIvUteRFi+04mH0DVBmIIcyq9t/J1j 6eJn9b8efjrIXsPAvsQTHcus0IS5nbMTx//f+Jxt8+U9WUiyBEFuSX+Y/E0hSw== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1683709388; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=koD4cPNLIm/3wGHC3EUteEyEyTTF+ReaD/tXyekbMOQ=; b=N6EJm5GFButoC3rcZLzq6db/2Fkhmh5G15xAkRJ/6bGGMMESFiSlG2yQR/2QCu2NS3m/oX c0ytQj07XX+2f0Bg== From: Anna-Maria Behnsen To: Andrea Righi cc: Steven Rostedt , Frederic Weisbecker , Ingo Molnar , Thomas Gleixner , Greg Kroah-Hartman , "Rafael J. Wysocki" , Jonathan Corbet , Salvatore Bonaccorso , Pawan Gupta , Mauro Carvalho Chehab , Daniel Lezcano , linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH] timers/nohz: introduce nohz_full_aggressive In-Reply-To: Message-ID: <2161b8c0-b08c-7bf7-4c99-3bb89ca44ad8@linutronix.de> References: <20230507090700.18470-1-andrea.righi@canonical.com> <20230507100852.54a354ca@rorschach.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 7 May 2023, Andrea Righi wrote: > On Sun, May 07, 2023 at 10:08:52AM -0400, Steven Rostedt wrote: > > > > [ Added Anna-Maria who is doing some timer work as well ] > > > > On Sun, 7 May 2023 11:07:00 +0200 > > Andrea Righi wrote: > > > > Now, I think what is really happening here is that you are somewhat > > simulating the results that Anna-Maria has indirectly. That is, you > > just prevent an idle CPU from waking up to handle interrupts when not > > needed. > > > > Anna-Maria, > > > > Do you have some patches that Andrea could test with? > > > > Thanks, > > > > -- Steve > > Thanks for looking at this (and I'm happy to help Anna-Maria with any > test). I posted v6 of the queue - but forgot to add you to cc list. Here is the current version: https://lore.kernel.org/lkml/20230510072817.116056-1-anna-maria@linutronix.de/ I have to mention, that there is still the issue with the fair scheduler which wakes up the CPU where the process_timeout() timer was enqueued, because it assumes that context is still cache hot. Thanks, Anna-Maria