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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,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 13D95C433ED for ; Tue, 13 Apr 2021 09:36:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9B0526120E for ; Tue, 13 Apr 2021 09:36:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9B0526120E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 04EE66B0036; Tue, 13 Apr 2021 05:36:12 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 0260D6B006E; Tue, 13 Apr 2021 05:36:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E2FD26B0070; Tue, 13 Apr 2021 05:36:11 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0143.hostedemail.com [216.40.44.143]) by kanga.kvack.org (Postfix) with ESMTP id C7FDA6B0036 for ; Tue, 13 Apr 2021 05:36:11 -0400 (EDT) Received: from smtpin40.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 71818180ACF75 for ; Tue, 13 Apr 2021 09:36:11 +0000 (UTC) X-FDA: 78026837742.40.765307C Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf28.hostedemail.com (Postfix) with ESMTP id 2636B200025C for ; Tue, 13 Apr 2021 09:36:12 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 9B1EEAF1B; Tue, 13 Apr 2021 09:36:09 +0000 (UTC) Subject: Re: [PATCH v2 resend] mm/memory_hotplug: Make unpopulated zones PCP structures unreachable during hot remove To: Mel Gorman Cc: Andrew Morton , Oscar Salvador , "Michael S. Tsirkin" , Alexander Duyck , Minchan Kim , Michal Hocko , David Hildenbrand , Linux-MM , LKML References: <20210412120842.GY3697@techsingularity.net> <20210412140852.GZ3697@techsingularity.net> From: Vlastimil Babka Message-ID: Date: Tue, 13 Apr 2021 11:36:08 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210412140852.GZ3697@techsingularity.net> Content-Type: text/plain; charset=iso-8859-15 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 2636B200025C X-Stat-Signature: 9c4gdsryfuk3beyqiikitoncisi5xzi3 Received-SPF: none (suse.cz>: No applicable sender policy available) receiver=imf28; identity=mailfrom; envelope-from=""; helo=mx2.suse.de; client-ip=195.135.220.15 X-HE-DKIM-Result: none/none X-HE-Tag: 1618306572-784081 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 4/12/21 4:08 PM, Mel Gorman wrote: > On Mon, Apr 12, 2021 at 02:40:18PM +0200, Vlastimil Babka wrote: >> On 4/12/21 2:08 PM, Mel Gorman wrote: > > the pageset structures in place would be much more straight-forward > assuming the structures were not allocated in the zone that is being > hot-removed. I would expect this is not possible, at least for ZONE_MOVABLE, as the percpu allocations should be GFP_KERNEL. And it's not realistic to expect offlining to succeed at all without using ZONE_MOVABLE. AFAIK even Oscar's work on using the node to self-contain its own structures is only applicable to struct pages, not percpu allocations?