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=-2.0 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 0532BC11FF5 for ; Mon, 23 Sep 2019 20:35:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CC09320673 for ; Mon, 23 Sep 2019 20:35:08 +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="Rp7KwCGB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2502785AbfIWUfH (ORCPT ); Mon, 23 Sep 2019 16:35:07 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:56884 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2502755AbfIWUfE (ORCPT ); Mon, 23 Sep 2019 16:35:04 -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=jeUp5+lKmcF/04ueHLJZUYIvt6Ip7WoukEyBumn2fVY=; b=Rp7KwCGBA1u0fTRuTtn353Iqg U1m+WAQt9nn2fAGVujebKUGETSc3lGylxo6ybOFrC6OjqOh6jQ3v/DS5f3WAkIPyz8mslZ534nPPF w/unipekNmfUEpWS+8sKsDNny4hh/TUmdhJAPIZWH2ZRICzTYlxFR1ynoVzBW1pYsSzPlTXy9kFo8 Isg6dRFXpBOi7a6PiA7uGzWX65FTAfllSiv/KpO5JJ5OOAofnU1CPXj0xiiTFQerXgpuCzvcT/6/Q SuqnTR2lR5rXkZN2iOh+yxAo8ns7Qujb+vZw/+amd8qwDo2R1+BLFhPLMDyxnUTx5OlVv5h2LyDch CDhZ19tzw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by bombadil.infradead.org with esmtpsa (Exim 4.92.2 #3 (Red Hat Linux)) id 1iCV2F-0002BC-Is; Mon, 23 Sep 2019 20:34:15 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id C0BAA301A7A; Mon, 23 Sep 2019 22:33:25 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 0BAD120D80D4E; Mon, 23 Sep 2019 22:34:11 +0200 (CEST) Date: Mon, 23 Sep 2019 22:34:10 +0200 From: Peter Zijlstra To: Michal Hocko Cc: Yunsheng Lin , catalin.marinas@arm.com, will@kernel.org, mingo@redhat.com, bp@alien8.de, rth@twiddle.net, ink@jurassic.park.msu.ru, mattst88@gmail.com, benh@kernel.crashing.org, paulus@samba.org, mpe@ellerman.id.au, heiko.carstens@de.ibm.com, gor@linux.ibm.com, borntraeger@de.ibm.com, ysato@users.sourceforge.jp, dalias@libc.org, davem@davemloft.net, ralf@linux-mips.org, paul.burton@mips.com, jhogan@kernel.org, jiaxun.yang@flygoat.com, chenhc@lemote.com, akpm@linux-foundation.org, rppt@linux.ibm.com, anshuman.khandual@arm.com, tglx@linutronix.de, cai@lca.pw, robin.murphy@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, hpa@zytor.com, x86@kernel.org, dave.hansen@linux.intel.com, luto@kernel.org, len.brown@intel.com, axboe@kernel.dk, dledford@redhat.com, jeffrey.t.kirsher@intel.com, linux-alpha@vger.kernel.org, naveen.n.rao@linux.vnet.ibm.com, mwb@linux.vnet.ibm.com, linuxppc-dev@lists.ozlabs.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, sparclinux@vger.kernel.org, tbogendoerfer@suse.de, linux-mips@vger.kernel.org, rafael@kernel.org, gregkh@linuxfoundation.org Subject: Re: [PATCH v6] numa: make node_to_cpumask_map() NUMA_NO_NODE aware Message-ID: <20190923203410.GI2369@hirez.programming.kicks-ass.net> References: <1568724534-146242-1-git-send-email-linyunsheng@huawei.com> <20190923151519.GE2369@hirez.programming.kicks-ass.net> <20190923152856.GB17206@dhcp22.suse.cz> <20190923154852.GG2369@hirez.programming.kicks-ass.net> <20190923165235.GD17206@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190923165235.GD17206@dhcp22.suse.cz> 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, Sep 23, 2019 at 06:52:35PM +0200, Michal Hocko wrote: > On Mon 23-09-19 17:48:52, Peter Zijlstra wrote: > To the NUMA_NO_NODE itself. Your earlier email noted: > : > + > : > if ((unsigned)node >= nr_node_ids) { > : > printk(KERN_WARNING > : > "cpumask_of_node(%d): (unsigned)node >= nr_node_ids(%u)\n", > : > : I still think this makes absolutely no sense what so ever. > > Did you mean the NUMA_NO_NODE handling or the specific node >= nr_node_ids > check? The NUMA_NO_NODE thing. It's is physical impossibility. And if the device description doesn't give us a node, then the description is incomplete and wrong and we should bloody well complain about it. > Because as to NUMA_NO_NODE I believe this makes sense because this is > the only way that a device is not bound to any numa node. Which is a physical impossibility. > I even the > ACPI standard is considering this optional. Yunsheng Lin has referred to > the specific part of the standard in one of the earlier discussions. > Trying to guess the node affinity is worse than providing all CPUs IMHO. I'm saying the ACPI standard is wrong. Explain to me how it is physically possible to have a device without NUMA affinity in a NUMA system? 1) The fundamental interconnect is not uniform. 2) The device needs to actually be somewhere. >From these it seems to follow that access to the device is subject to NUMA.