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 X-Spam-Level: X-Spam-Status: No, score=-4.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 7454EC433DF for ; Fri, 7 Aug 2020 15:06:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4700A2075D for ; Fri, 7 Aug 2020 15:06:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="g5IlGoKE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726660AbgHGPGq (ORCPT ); Fri, 7 Aug 2020 11:06:46 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:47195 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726644AbgHGPGo (ORCPT ); Fri, 7 Aug 2020 11:06:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1596812803; 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=JhwrzTXfET2LA1451/hxvE9hVV0gEaq7zNxUuYFQSI8=; b=g5IlGoKExUtQVeyoHGEn5nSGIW/q/0bAdRAUU2MdcozPRC4Vff/E6LUyiQu6C8RKS1V3we DBWFp9s66WfJpx6QaM3v+Pc7hSRIvtyXWU24PhDpak+TvVIS63MydpAXQwjypn86sdqo/Q BqwzZCzjTpEdBIulKFCvUcp4720Dk0Y= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-214-3SRreF7pNmajAVbbhYJYHw-1; Fri, 07 Aug 2020 11:06:39 -0400 X-MC-Unique: 3SRreF7pNmajAVbbhYJYHw-1 Received: by mail-wm1-f71.google.com with SMTP id q15so898856wmj.6 for ; Fri, 07 Aug 2020 08:06:39 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=JhwrzTXfET2LA1451/hxvE9hVV0gEaq7zNxUuYFQSI8=; b=iHtRY6FgBvq/FXYCF2E3DYnfKWgoQ4yBa52Il3ASk5ln7YJsqM2w1HCVP0Ct63QYlP iex9ORIUgbqaLM1pL8cvUmdSLqecEx+nsnUW/DKJ96/FiRlwrs+T2RiJ8Zy0sQBMG10w GGb95sFgPx+TT4+n32Iw8sDUGlAi3unOygiHVgGS8zNAda111VEy67HBsEKA9rZcdVoa xGXpWUUPmZiKI1c7FTbwPXY9W+/kyFhSB9nPEjvL6zkJr9+oUhAUFgnsD57W420uZ5bj jlz6sPa0Xkt5ugfy6JM3e2eiTRagDRlSoqHwShDf+wWgkMTIknmlVL9htEYDr5yqVw+d YDyg== X-Gm-Message-State: AOAM531gGdrHTNmvrz3g3xTin4gG6iDg0utGLKI3XpHCToXUTB88hP/s DH0LakCTFr5zCppzzVQFxt98q+0GA2ngaeW9tt2YMVhHULNgMKifJREZa5ckU6s6ISS6P5MxPtZ idIQ1P2QIvqmYLBgJxtuD44CY X-Received: by 2002:a1c:4944:: with SMTP id w65mr12628671wma.169.1596812798543; Fri, 07 Aug 2020 08:06:38 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzz3bB8s79VoyLMKdQfTDQFEefXwjmaE+HQ1FHOTgL6uERRqtI+zyNDHX21bOJoliJQoT+/NQ== X-Received: by 2002:a1c:4944:: with SMTP id w65mr12628654wma.169.1596812798313; Fri, 07 Aug 2020 08:06:38 -0700 (PDT) Received: from localhost.localdomain ([151.29.36.84]) by smtp.gmail.com with ESMTPSA id l1sm11111868wrb.12.2020.08.07.08.06.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Aug 2020 08:06:37 -0700 (PDT) Date: Fri, 7 Aug 2020 17:06:35 +0200 From: Juri Lelli To: peterz@infradead.org Cc: luca abeni , mingo@redhat.com, rostedt@goodmis.org, tglx@linutronix.de, linux-kernel@vger.kernel.org, tommaso.cucinotta@santannapisa.it, alessio.balsini@gmail.com, bristot@redhat.com, dietmar.eggemann@arm.com, linux-rt-users@vger.kernel.org, mtosatti@redhat.com, williams@redhat.com, valentin.schneider@arm.com Subject: Re: [RFC PATCH v2 6/6] sched/fair: Implement starvation monitor Message-ID: <20200807150635.GU42956@localhost.localdomain> References: <20200807095051.385985-1-juri.lelli@redhat.com> <20200807095604.GO42956@localhost.localdomain> <20200807152832.591f462e@nowhere> <20200807134353.GR42956@localhost.localdomain> <20200807141346.GL2674@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200807141346.GL2674@hirez.programming.kicks-ass.net> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/08/20 16:13, peterz@infradead.org wrote: > On Fri, Aug 07, 2020 at 03:43:53PM +0200, Juri Lelli wrote: > > > Right, but I fear we won't be able to keep current behavior for wakeups: > > RT with highest prio always gets scheduled right away? > > If you consider RT throttling, that's already not the case. We can > consider this fair server to be just another way to implement that. > > At some point, we'll have have to preempt higher priority tasks, that's > the entire point of the thing after all. > Ah, indeed. But I was thinking we might try to do a little "better" wrt to RT Throttling while we are at it. :-) This proposal has the potential to be more flexible and to kick in only when really needed.