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=-2.4 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 6730DC46470 for ; Wed, 8 Aug 2018 09:30:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D30D121722 for ; Wed, 8 Aug 2018 09:30:25 +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="C8OzGjYN" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D30D121722 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 S1727457AbeHHLtP (ORCPT ); Wed, 8 Aug 2018 07:49:15 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:47672 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726927AbeHHLtP (ORCPT ); Wed, 8 Aug 2018 07:49:15 -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=yBy8GC4j5bX113zc5eBNgEEebzQMiz9HLG0ZMm87CeM=; b=C8OzGjYNW9e6MECK1IoOFdbrl Pzq22RZVdJwqlcnUxYtDOsVbrvaEtRUA+KvWYCpJ4782bdodWv0bl31aNafUYdjvydOL9oOhEK3xr OcOl3486xGXzyswJ9Tl96Cx9VL63kgS4flUT/IPcAbte8YUy2AJs1yfnrboCcRGFUx3KdlzilR456 RfP7NaV/kBWJkBjEdxCS4HCfLSWKj5ODP5zegrpALMzOr8es6ob+28YAoSVgojDNYCX6IwXBmLab/ jNexyCdvxwvQh/v6AuTlFyMF2QTKBc6V3SN3u+voN8wI5NEgv5/AujYpYltQ1pAPQK02XWvCEP5Nt Mkbu9xqrg==; 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 1fnKnK-0008Uk-7B; Wed, 08 Aug 2018 09:30:18 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 6EFCA20437393; Wed, 8 Aug 2018 11:30:16 +0200 (CEST) Date: Wed, 8 Aug 2018 11:30:16 +0200 From: Peter Zijlstra To: Srikar Dronamraju Cc: Ingo Molnar , LKML , Mel Gorman , Rik van Riel , Thomas Gleixner , Michael Ellerman , Heiko Carstens , Suravee Suthikulpanit , Andre Wild Subject: Re: [PATCH] sched/topology: Use Identity node only if required Message-ID: <20180808093016.GS2512@hirez.programming.kicks-ass.net> References: <1533712172-11428-1-git-send-email-srikar@linux.vnet.ibm.com> <20180808075840.GO2494@hirez.programming.kicks-ass.net> <20180808081942.GA37418@linux.vnet.ibm.com> <20180808084302.GQ2494@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180808084302.GQ2494@hirez.programming.kicks-ass.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 Wed, Aug 08, 2018 at 10:43:02AM +0200, Peter Zijlstra wrote: > On Wed, Aug 08, 2018 at 01:19:42AM -0700, Srikar Dronamraju wrote: > > We could fix the numa topology to be NUMA_DIRECT for 2 node machines, by > > checking if sched_domains_numa_levels == 2, but then I dont know what it > > means for a system that has only NODE but not NUMA level. > > You have a point there; I think we should not have added the NODE thing > to sched_domains_numa_level, let me see if we can fix that sanely. Hurm,. looking this over I don't see anything better than changing that NUMA_DIRECT test to <= 2. But as the comment says, DIRECT means: all nodes are directly connected, or not a NUMA system. A system with a single node is not a NUMA system and would thus qualify.