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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,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 91DF3C43441 for ; Thu, 15 Nov 2018 13:57:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 50F242082A for ; Thu, 15 Nov 2018 13:57:13 +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="t+J8Nuot" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 50F242082A 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 S2388419AbeKPAFI (ORCPT ); Thu, 15 Nov 2018 19:05:08 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:58080 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729010AbeKPAFI (ORCPT ); Thu, 15 Nov 2018 19:05:08 -0500 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=lv3KDJJ4735A98C+qu8tUwqG7ME2lcOUmquG7PrRZ2c=; b=t+J8NuotawshzGhVnl5Owx6XE z+dz0GZWk8vqcBsY8IvzDc8ufeZQPat4VZW5ZVgLGjVwgLmGCdsw9yRUWSD5boVtT3tZCGUUxl5Xi jJZGX7tBWsRwWV0ibQd1sl71U/o8TT30APN/ZCdFAblFBmaodC68+lWhqzhkeFMpewcRr0gKJzR6s lHSXiAh0wCG4OqTT+JWgKQeocyERCcDN5Sl6I9f7zOdNShfPYl0ItM1l4+AMqv4b3ryYefy7O3xLn RITL/NTQjmqYSnuJEIVpuIOVbTK7at5TG+0Oj19V5NSo7bySX//5115np4itn1Le2BduI6X5gq7lb bONcz+6PA==; Received: from willy by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1gNI8s-0003bo-Py; Thu, 15 Nov 2018 13:57:10 +0000 Date: Thu, 15 Nov 2018 05:57:10 -0800 From: Matthew Wilcox To: Keith Busch Cc: linux-kernel@vger.kernel.org, linux-acpi@vger.kernel.org, linux-mm@kvack.org, Greg Kroah-Hartman , Rafael Wysocki , Dave Hansen , Dan Williams Subject: Re: [PATCH 1/7] node: Link memory nodes to their compute nodes Message-ID: <20181115135710.GD19286@bombadil.infradead.org> References: <20181114224921.12123-2-keith.busch@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181114224921.12123-2-keith.busch@intel.com> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 14, 2018 at 03:49:14PM -0700, Keith Busch wrote: > Memory-only nodes will often have affinity to a compute node, and > platforms have ways to express that locality relationship. > > A node containing CPUs or other DMA devices that can initiate memory > access are referred to as "memory iniators". A "memory target" is a > node that provides at least one phyiscal address range accessible to a > memory initiator. I think I may be confused here. If there is _no_ link from node X to node Y, does that mean that node X's CPUs cannot access the memory on node Y? In my mind, all nodes can access all memory in the system, just not with uniform bandwidth/latency.