Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751484AbdFZQNK (ORCPT ); Mon, 26 Jun 2017 12:13:10 -0400 Received: from merlin.infradead.org ([205.233.59.134]:60130 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751402AbdFZQND (ORCPT ); Mon, 26 Jun 2017 12:13:03 -0400 Date: Mon, 26 Jun 2017 18:12:50 +0200 From: Peter Zijlstra To: Rik van Riel Cc: linux-kernel@vger.kernel.org, jhladky@redhat.com, mingo@kernel.org, mgorman@suse.de Subject: Re: [PATCH 4/4] sched,fair: remove effective_load Message-ID: <20170626161250.GD4941@worktop> References: <20170623165530.22514-1-riel@redhat.com> <20170623165530.22514-5-riel@redhat.com> <20170626144437.GB4941@worktop> <20170626144611.GA5775@worktop> <1498488941.13083.43.camel@redhat.com> <20170626150401.GC4941@worktop> <1498490454.13083.45.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1498490454.13083.45.camel@redhat.com> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 825 Lines: 20 On Mon, Jun 26, 2017 at 11:20:54AM -0400, Rik van Riel wrote: > Oh, indeed. I guess in wake_affine() we should test > whether the CPUs are in the same NUMA node, rather than > doing cpus_share_cache() ? Well, since select_idle_sibling() is on LLC; the early test on cpus_share_cache(prev,this) seems to actually make sense. But then cutting out all the other bits seems wrong. Not in the least because !NUMA_BALACING should also still keep working. > Or, alternatively, have an update_numa_stats() variant > for numa_wake_affine() that works on the LLC level? I think we want to retain the existing behaviour for everything larger than LLC, and when NUMA_BALANCING, smaller than NUMA. Also note that your use of task_h_load() in the new numa thing suffers from exactly the problem effective_load() is trying to solve.