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_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT autolearn=ham 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 B44BAC433F5 for ; Fri, 7 Sep 2018 12:44:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6DF2B20844 for ; Fri, 7 Sep 2018 12:44:48 +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="Bln/YDQI" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6DF2B20844 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729606AbeIGRZd (ORCPT ); Fri, 7 Sep 2018 13:25:33 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:41654 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727069AbeIGRZd (ORCPT ); Fri, 7 Sep 2018 13:25:33 -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=119+pvNU79vGuxof8DLa1VB17ARPHN7FSjlDSiKECL4=; b=Bln/YDQIYgX2+529kZhq6indO y7CXDVh30bVmDWyP6haiYM1uEWjp44Z3E9OziSdn6TxA3SdjqORmg5ERM9tkh+k9ClsKVGf7sk8au gUfheMn/H/Jv1j6pYhANpTZy6sWjGfCGwzAnfItuZWpHy14a5hozl2AfedWsMKvWWGxn9Cr0UBY2H 0sSJN1xq85JBHBYmhF/OEDAzT8+lB4UM0UGmZ8m6oZBL7ka3EPb4ChtwQR0fRfMqkIYS2ssizwi6u JwHpuHIv1qddR7WwGcHOAlaaYc3hsPAVo7kfmoizdFk2yXcXGcs2BVNPJdMuPCnRpZFR6SQ8w7xeN PlrEDegTA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1fyG7l-0006Cc-Pn; Fri, 07 Sep 2018 12:44:34 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 1A24A20210310; Fri, 7 Sep 2018 14:44:32 +0200 (CEST) Date: Fri, 7 Sep 2018 14:44:32 +0200 From: Peter Zijlstra To: Mel Gorman Cc: Srikar Dronamraju , Ingo Molnar , Rik van Riel , LKML Subject: Re: [PATCH 4/4] sched/numa: Do not move imbalanced load purely on the basis of an idle CPU Message-ID: <20180907124432.GN24082@hirez.programming.kicks-ass.net> References: <20180907101139.20760-1-mgorman@techsingularity.net> <20180907101139.20760-5-mgorman@techsingularity.net> <20180907113309.GU24106@hirez.programming.kicks-ass.net> <20180907123739.GE1719@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180907123739.GE1719@techsingularity.net> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 07, 2018 at 01:37:39PM +0100, Mel Gorman wrote: > On Fri, Sep 07, 2018 at 01:33:09PM +0200, Peter Zijlstra wrote: > > > --- > > > kernel/sched/fair.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > > > index d59d3e00a480..d4c289c11012 100644 > > > --- a/kernel/sched/fair.c > > > +++ b/kernel/sched/fair.c > > > @@ -1560,7 +1560,7 @@ static bool task_numa_compare(struct task_numa_env *env, > > > goto unlock; > > > > > > if (!cur) { > > > - if (maymove || imp > env->best_imp) > > > + if (maymove) > > > goto assign; > > > else > > > goto unlock; > > > > Srikar's patch here: > > > > http://lkml.kernel.org/r/1533276841-16341-4-git-send-email-srikar@linux.vnet.ibm.com > > > > Also frobs this condition, but in a less radical way. Does that yield > > similar results? > > I can check. I do wonder of course if the less radical approach just means > that automatic NUMA balancing and the load balancer simply disagree about > placement at a different time. It'll take a few days to have an answer as > the battery of workloads to check this take ages. Yeah, I was afraid it would.. Srikar, can you also evaluate, I suspect we'll have to pick one of these two patches.