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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 277FEC76186 for ; Mon, 29 Jul 2019 20:11:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DC374205F4 for ; Mon, 29 Jul 2019 20:11:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="ONNUn0+v" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730292AbfG2ULq (ORCPT ); Mon, 29 Jul 2019 16:11:46 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:44508 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727987AbfG2ULo (ORCPT ); Mon, 29 Jul 2019 16:11:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; 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:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=tVzGNh46p11xJCp/QVEqOCFK+AgFdqni/w2NTMqBXpI=; b=ONNUn0+v6UKGefnLp5MlICEj8 rs8jlW8TeLmb6brykyu7WcXTpzoSEfnFKN2gctJaqCiYf3EOqHq3hx8B3WnL3+pBaZTx59kERW4/k 01EOXsLxSe8YpwCZOi4DlTw19lrVIKWakVQXSx+P7kPfrhjtA5/OMx4SHf33bdCYIeox6Ksbt/tCf j88syn/qIMQNzel7ONs4JM9bF65DxADLWHOubUTPVrsZKg/sakq1GJ/fjoIxJxu5F/giZ6/eTdbzS Q294ksVxVF7Ww7lUoe2qtKQATn96WFumplhPzXjaHOUtzF4kbEHfezrdK+nlUlAV7Wj++0ODviCcC LvmH7Crbw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hsBza-0004j9-5c; Mon, 29 Jul 2019 20:11:34 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 971CE20AF2C00; Mon, 29 Jul 2019 22:11:32 +0200 (CEST) Date: Mon, 29 Jul 2019 22:11:32 +0200 From: Peter Zijlstra To: Rik van Riel Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, pjt@google.com, dietmar.eggemann@arm.com, mingo@redhat.com, morten.rasmussen@arm.com, tglx@linutronix.de, mgorman@techsingularity.net, vincent.guittot@linaro.org Subject: Re: [PATCH 03/14] sched,fair: redefine runnable_load_avg as the sum of task_h_load Message-ID: <20190729201132.GS31398@hirez.programming.kicks-ass.net> References: <20190722173348.9241-1-riel@surriel.com> <20190722173348.9241-4-riel@surriel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190722173348.9241-4-riel@surriel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 22, 2019 at 01:33:37PM -0400, Rik van Riel wrote: > The runnable_load magic is used to quickly propagate information about > runnable tasks up the hierarchy of runqueues. The runnable_load_avg is > mostly used for the load balancing code, which only examines the value at > the root cfs_rq. > > Redefine the root cfs_rq runnable_load_avg to be the sum of task_h_loads > of the runnable tasks. This works because the hierarchical runnable_load of > a task is already equal to the task_se_h_load today. This provides enough > information to the load balancer. > > The runnable_load_avg of the cgroup cfs_rqs does not appear to be > used for anything, so don't bother calculating those. > > This removes one of the things that the code currently traverses the > cgroup hierarchy for, and getting rid of it brings us one step closer > to a flat runqueue for the CPU controller. Nice!