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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 0C0A3C4360D for ; Wed, 25 Sep 2019 13:25:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D747E20835 for ; Wed, 25 Sep 2019 13:25:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569417953; bh=6BCSrWonY5sLbA7pMH709VwyeYjql8muF5bTgRT1kp4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=drIADTtvFOHzJlBKmfECJ5x70dgx2SX0wLlDz0XD9KlKxclfmVHHKeTHGmKFQMj57 qmfVo4jeUf0+L+EOq7U2RX2oKY/rmKpayQXpsbGg56wuS5ZHEF5DnB8BT2hPvbt3sL xDBu8YBBCJT97FVA1k4tR4pyUdUyTwpqoLSyJqyI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406406AbfIYNZx (ORCPT ); Wed, 25 Sep 2019 09:25:53 -0400 Received: from mx2.suse.de ([195.135.220.15]:57812 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S2406079AbfIYNZw (ORCPT ); Wed, 25 Sep 2019 09:25:52 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 0D081B0B6; Wed, 25 Sep 2019 13:25:49 +0000 (UTC) Date: Wed, 25 Sep 2019 15:25:44 +0200 From: Michal Hocko To: Peter Zijlstra 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: <20190925132544.GL23050@dhcp22.suse.cz> References: <20190924091714.GJ2369@hirez.programming.kicks-ass.net> <20190924105622.GH23050@dhcp22.suse.cz> <20190924112349.GJ2332@hirez.programming.kicks-ass.net> <20190924115401.GM23050@dhcp22.suse.cz> <20190924120943.GP2349@hirez.programming.kicks-ass.net> <20190924122500.GP23050@dhcp22.suse.cz> <20190924124325.GQ2349@hirez.programming.kicks-ass.net> <20190924125936.GR2349@hirez.programming.kicks-ass.net> <20190924131939.GS23050@dhcp22.suse.cz> <20190925104040.GD4553@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190925104040.GD4553@hirez.programming.kicks-ass.net> 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 Wed 25-09-19 12:40:40, Peter Zijlstra wrote: > On Tue, Sep 24, 2019 at 03:19:39PM +0200, Michal Hocko wrote: > > > > The below would get rid of the PMU and workqueue warnings with no > > > side-effects (the device isn't used for anything except sysfs). > > > > Hardcoding to 0 is simply wrong, if the node0 is cpuless for example... > > It doesn't matter.... that 0 is _never_ used. These are fake devices, > and all we care about is getting rid of that error. That is a very subtle and hard to review assumption. Even if this holds now a future change might easily break this AFAIU. It also assumes that you catch all such special devices. I am sorry but I still do not understand why you consider this whack a mole better then simply live with the fact that NUMA_NO_NODE is a reality and that using the full cpu mask is a reasonable answer to that. Anyway, I feel we are loop here so I will leave out the final decision to you. > If it makes you feel better we can make it -2 and have dev_to_node() > WARN if it ever sees one. That would help -- Michal Hocko SUSE Labs