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=-1.0 required=3.0 tests=MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS 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 DC1C9C2BA2B for ; Thu, 9 Apr 2020 15:33:25 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A189E206E9 for ; Thu, 9 Apr 2020 15:33:25 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A189E206E9 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4E6AF8E000E; Thu, 9 Apr 2020 11:33:25 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 496258E0006; Thu, 9 Apr 2020 11:33:25 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 385668E000E; Thu, 9 Apr 2020 11:33:25 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0082.hostedemail.com [216.40.44.82]) by kanga.kvack.org (Postfix) with ESMTP id 2BFDC8E0006 for ; Thu, 9 Apr 2020 11:33:25 -0400 (EDT) Received: from smtpin11.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 0908A4DC7 for ; Thu, 9 Apr 2020 15:33:25 +0000 (UTC) X-FDA: 76688710770.11.tank98_3ae234618be19 X-HE-Tag: tank98_3ae234618be19 X-Filterd-Recvd-Size: 5804 Received: from mail-wr1-f68.google.com (mail-wr1-f68.google.com [209.85.221.68]) by imf45.hostedemail.com (Postfix) with ESMTP for ; Thu, 9 Apr 2020 15:33:24 +0000 (UTC) Received: by mail-wr1-f68.google.com with SMTP id 31so12437563wre.5 for ; Thu, 09 Apr 2020 08:33:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=eU8HVKPcEFasCzGb3YcmSlRzYlNKnx8U/U7SeGkKTM4=; b=t4aYJ5iF/+Gk1gjGlPKlUrKGWmIAL9i3+9hRga6GaQ81EvW2nuL+h4ylxs9EMyAIao r3mNfAPfIgX8OzI/CpaY0w9EZOkhWi46sXq8jpLaDBK5fHaaNiGn8mnIOeP2Zf4m1rBt nY8n9gVeYvMakZo40mrWZOmaIya3gjKRMCouZmJa4rbcgZh6qX7VR/yySm9L1iAEUZ1r wJi2JXfMpFCRnaRs1hcJle3swkQb06KmMciIN2UQ4Ckn0IXPSeES2hGfBUTTbIsOzYBO cO0NNzdqqd93Tta0A4SNQ/vZS4cBXjwqqsmO8d5XuOo+LnV4Zh/W8hHF9G9ptKAcAukd I4Lg== X-Gm-Message-State: AGi0PuYyfBLa+yspMiDEAOjNekf4x7m3VaL669WkgjF03WRHitaOvtuk 2qJWV0tLESkPXowTXhHYpx0= X-Google-Smtp-Source: APiQypLhnJ0ArE660dAIRKPg+UfX8htjcJDtxqzlxSXIrBucMDxX/FoA+uq76nGwKcjVTj7PGoGnsA== X-Received: by 2002:a5d:5112:: with SMTP id s18mr15000370wrt.306.1586446403503; Thu, 09 Apr 2020 08:33:23 -0700 (PDT) Received: from localhost (ip-37-188-180-223.eurotel.cz. [37.188.180.223]) by smtp.gmail.com with ESMTPSA id o67sm4335914wmo.5.2020.04.09.08.33.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 09 Apr 2020 08:33:22 -0700 (PDT) Date: Thu, 9 Apr 2020 17:33:21 +0200 From: Michal Hocko To: Baoquan He Cc: Mike Rapoport , Hoan Tran , Catalin Marinas , Will Deacon , Andrew Morton , Vlastimil Babka , Oscar Salvador , Pavel Tatashin , Alexander Duyck , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , "David S. Miller" , Heiko Carstens , Vasily Gorbik , Christian Borntraeger , "open list:MEMORY MANAGEMENT" , linux-arm-kernel@lists.infradead.org, linux-s390@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, lho@amperecomputing.com, mmorana@amperecomputing.com Subject: Re: [PATCH RFC] mm: remove CONFIG_HAVE_MEMBLOCK_NODE_MAP (was: Re: [PATCH v3 0/5] mm: Enable CONFIG_NODES_SPAN_OTHER_NODES by default for NUMA) Message-ID: <20200409153321.GQ18386@dhcp22.suse.cz> References: <1585420282-25630-1-git-send-email-Hoan@os.amperecomputing.com> <20200330074246.GA14243@dhcp22.suse.cz> <20200330092127.GB30942@linux.ibm.com> <20200330095843.GF14243@dhcp22.suse.cz> <20200331215618.GG30942@linux.ibm.com> <20200401054227.GC2129@MiWiFi-R3L-srv> <20200401075155.GH30942@linux.ibm.com> <20200402080144.GK22681@dhcp22.suse.cz> <20200409144119.GE2129@MiWiFi-R3L-srv> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200409144119.GE2129@MiWiFi-R3L-srv> X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu 09-04-20 22:41:19, Baoquan He wrote: > On 04/02/20 at 10:01am, Michal Hocko wrote: > > On Wed 01-04-20 10:51:55, Mike Rapoport wrote: > > > Hi, > > > > > > On Wed, Apr 01, 2020 at 01:42:27PM +0800, Baoquan He wrote: > > [...] > > > > From above information, we can remove HAVE_MEMBLOCK_NODE_MAP, and > > > > replace it with CONFIG_NUMA. That sounds more sensible to store nid into > > > > memblock when NUMA support is enabled. > > > > > > Replacing CONFIG_HAVE_MEMBLOCK_NODE_MAP with CONFIG_NUMA will work, but > > > this will not help cleaning up the whole node/zone initialization mess and > > > we'll be stuck with two implementations. > > > > Yeah, this is far from optimal. > > > > > The overhead of enabling HAVE_MEMBLOCK_NODE_MAP is only for init time as > > > most architectures will anyway discard the entire memblock, so having it in > > > a UMA arch won't be a problem. The only exception is arm that uses > > > memblock for pfn_valid(), here we may also think about a solution to > > > compensate the addition of nid to the memblock structures. > > > > Well, we can make memblock_region->nid defined only for CONFIG_NUMA. > > memblock_get_region_node would then unconditionally return 0 on UMA. > > Essentially the same way we do NUMA for other MM code. I only see few > > direct usage of region->nid. > > Checked code again, seems HAVE_MEMBLOCK_NODE_MAP is selected directly in > all ARCHes which support it. Means HAVE_MEMBLOCK_NODE_MAP is enabled by > default on those ARCHes, and has no dependency on CONFIG_NUMA at all. > E.g on x86, it just calls free_area_init_nodes() in generic code path, > while free_area_init_nodes() is defined in CONFIG_HAVE_MEMBLOCK_NODE_MAP > ifdeffery scope. So I tend to agree with Mike to remove > HAVE_MEMBLOCK_NODE_MAP firstly on all ARCHes. We can check if it's worth > only defining memblock_region->nid for CONFIG_NUMA case after > HAVE_MEMBLOCK_NODE_MAP is removed. This can surely go in separate patches. What I meant to say is the region->nid is by definition 0 on !CONFIG_NUMA. -- Michal Hocko SUSE Labs