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 69119CA5512 for ; Wed, 13 Sep 2023 09:04:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239195AbjIMJER (ORCPT ); Wed, 13 Sep 2023 05:04:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53094 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239149AbjIMJEP (ORCPT ); Wed, 13 Sep 2023 05:04:15 -0400 Received: from desiato.infradead.org (desiato.infradead.org [IPv6:2001:8b0:10b:1:d65d:64ff:fe57:4e05]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6D6BF1999 for ; Wed, 13 Sep 2023 02:04:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=desiato.20200630; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=CcPs1loMse6j9I5mnXT5xMOl9FMdZpWS3PB4AoazHUs=; b=AigZBCojNkNHoE2JG0mWdvw/9K sp7rSb1+2jyE9ucAnnmaCkpP7G3qGMM5TgaW53nO1FZe1SP5R6IDPtxbj5mBqCndi8I7fjGT8Dl4I MFpibKiyVZs9Ja0evQ4cj/7m7eQ6MeAlmfZxG1U4bJBcJz2WJHUTYq/lwFNTwYT09OqrYKURvvNok bM2lHthmhE+9qc9aF53OGTwZx5vS8YQxRtAz3VHadqmIPc+cU/ARt/mVyTcH74VgpGPW/wd/ZYAeo RTayjqrZQ5+LDt8Cu0WqYxapvjsEb2DXTqME6KM/SnAx/IsfMCRb6dz0i7GENYB0HELSOezSmViLH tPvJeKbQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by desiato.infradead.org with esmtpsa (Exim 4.96 #2 (Red Hat Linux)) id 1qgLmT-006wJM-0Z; Wed, 13 Sep 2023 09:03:31 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 1000) id 48F39300348; Wed, 13 Sep 2023 11:03:30 +0200 (CEST) Date: Wed, 13 Sep 2023 11:03:30 +0200 From: Peter Zijlstra To: Sebastian Andrzej Siewior Cc: mingo@kernel.org, vincent.guittot@linaro.org, linux-kernel@vger.kernel.org, juri.lelli@redhat.com, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, bristot@redhat.com, corbet@lwn.net, qyousef@layalina.io, chris.hyser@oracle.com, patrick.bellasi@matbug.net, pjt@google.com, pavel@ucw.cz, qperret@google.com, tim.c.chen@linux.intel.com, joshdon@google.com, timj@gnu.org, kprateek.nayak@amd.com, yu.c.chen@intel.com, youssefesmat@chromium.org, joel@joelfernandes.org, efault@gmx.de, tglx@linutronix.de Subject: Re: [PATCH 07/15] sched/smp: Use lag to simplify cross-runqueue placement Message-ID: <20230913090330.GC692@noisy.programming.kicks-ass.net> References: <20230531115839.089944915@infradead.org> <20230531124604.068911180@infradead.org> <20230912153221.lSL8YgJJ@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230912153221.lSL8YgJJ@linutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 12, 2023 at 05:32:21PM +0200, Sebastian Andrzej Siewior wrote: > On 2023-05-31 13:58:46 [+0200], Peter Zijlstra wrote: > > --- a/kernel/sched/fair.c > > +++ b/kernel/sched/fair.c > > @@ -12492,22 +12440,9 @@ static void task_fork_fair(struct task_s > > > > cfs_rq = task_cfs_rq(current); > > curr = cfs_rq->curr; > > - if (curr) { > > + if (curr) > > update_curr(cfs_rq); > > - se->vruntime = curr->vruntime; > > - } > > place_entity(cfs_rq, se, 1); > > - > > - if (sysctl_sched_child_runs_first && curr && entity_before(curr, se)) { > > Since the removal of sysctl_sched_child_runs_first there is no user of > this anymore. There is still the sysctl file sched_child_runs_first with > no functionality. > Is this intended or should it be removed? Hurmph... I think that knob has been somewat dysfunctional for a long while and it might be time to remove it. Ingo?