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=-2.5 required=3.0 tests=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 60550C432C2 for ; Wed, 25 Sep 2019 13:28:29 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D827421D7C for ; Wed, 25 Sep 2019 13:28:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D827421D7C Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46df5Q2yx6zDqTM for ; Wed, 25 Sep 2019 23:28:26 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=softfail (mailfrom) smtp.mailfrom=kernel.org (client-ip=195.135.220.15; helo=mx1.suse.de; envelope-from=mhocko@kernel.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=fail (p=none dis=none) header.from=kernel.org Received: from mx1.suse.de (mx2.suse.de [195.135.220.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46df2V68ypzDqTM for ; Wed, 25 Sep 2019 23:25:53 +1000 (AEST) 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 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) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: dalias@libc.org, linux-sh@vger.kernel.org, catalin.marinas@arm.com, dave.hansen@linux.intel.com, heiko.carstens@de.ibm.com, jiaxun.yang@flygoat.com, linux-mips@vger.kernel.org, mwb@linux.vnet.ibm.com, paulus@samba.org, hpa@zytor.com, sparclinux@vger.kernel.org, chenhc@lemote.com, will@kernel.org, cai@lca.pw, linux-s390@vger.kernel.org, ysato@users.sourceforge.jp, x86@kernel.org, Yunsheng Lin , rppt@linux.ibm.com, borntraeger@de.ibm.com, dledford@redhat.com, mingo@redhat.com, jeffrey.t.kirsher@intel.com, jhogan@kernel.org, mattst88@gmail.com, len.brown@intel.com, gor@linux.ibm.com, anshuman.khandual@arm.com, gregkh@linuxfoundation.org, bp@alien8.de, luto@kernel.org, tglx@linutronix.de, naveen.n.rao@linux.vnet.ibm.com, linux-arm-kernel@lists.infradead.org, rth@twiddle.net, axboe@kernel.dk, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, ralf@linux-mips.org, tbogendoerfer@suse.de, paul.burton@mips.com, linux-alpha@vger.kernel.org, rafael@kernel.org, ink@jurassic.park.msu.ru, akpm@linux-foundation.org, robin.murphy@arm.com, davem@davemloft.net Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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