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=-5.2 required=3.0 tests=BAYES_00, 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 C437AC43461 for ; Tue, 13 Apr 2021 09:49:34 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 5F593613BC for ; Tue, 13 Apr 2021 09:49:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5F593613BC Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=techsingularity.net Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id A03876B0036; Tue, 13 Apr 2021 05:49:33 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9B40E6B006E; Tue, 13 Apr 2021 05:49:33 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 87B116B0070; Tue, 13 Apr 2021 05:49:33 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0131.hostedemail.com [216.40.44.131]) by kanga.kvack.org (Postfix) with ESMTP id 7050E6B0036 for ; Tue, 13 Apr 2021 05:49:33 -0400 (EDT) Received: from smtpin31.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 305A7180238DF for ; Tue, 13 Apr 2021 09:49:33 +0000 (UTC) X-FDA: 78026871426.31.5C71F7F Received: from outbound-smtp33.blacknight.com (outbound-smtp33.blacknight.com [81.17.249.66]) by imf25.hostedemail.com (Postfix) with ESMTP id 3EEE16000117 for ; Tue, 13 Apr 2021 09:49:28 +0000 (UTC) Received: from mail.blacknight.com (pemlinmail03.blacknight.ie [81.17.254.16]) by outbound-smtp33.blacknight.com (Postfix) with ESMTPS id D0D19BAC03 for ; Tue, 13 Apr 2021 10:49:23 +0100 (IST) Received: (qmail 31546 invoked from network); 13 Apr 2021 09:49:23 -0000 Received: from unknown (HELO techsingularity.net) (mgorman@techsingularity.net@[84.203.22.4]) by 81.17.254.9 with ESMTPSA (AES256-SHA encrypted, authenticated); 13 Apr 2021 09:49:23 -0000 Date: Tue, 13 Apr 2021 10:49:20 +0100 From: Mel Gorman To: Vlastimil Babka Cc: Andrew Morton , Oscar Salvador , "Michael S. Tsirkin" , Alexander Duyck , Minchan Kim , Michal Hocko , David Hildenbrand , Linux-MM , LKML Subject: Re: [PATCH v2 resend] mm/memory_hotplug: Make unpopulated zones PCP structures unreachable during hot remove Message-ID: <20210413094920.GC3697@techsingularity.net> References: <20210412120842.GY3697@techsingularity.net> <20210412140852.GZ3697@techsingularity.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Queue-Id: 3EEE16000117 X-Stat-Signature: gm9ojzm16in6tj9jjug3wssigoxwd89p X-Rspamd-Server: rspam02 Received-SPF: none (techsingularity.net>: No applicable sender policy available) receiver=imf25; identity=mailfrom; envelope-from=""; helo=outbound-smtp33.blacknight.com; client-ip=81.17.249.66 X-HE-DKIM-Result: none/none X-HE-Tag: 1618307368-369957 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 Tue, Apr 13, 2021 at 11:36:08AM +0200, Vlastimil Babka wrote: > 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. True. > 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? That I don't know as I didn't check although in general, it would be somewhat unfortunate if per-cpu structures were remote. It wouldn't be critical given that they'll be in cache assuming the per-cpu structures are not straddling cache lines. -- Mel Gorman SUSE Labs