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,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 9BA52C433B4 for ; Wed, 21 Apr 2021 08:35:31 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 0865A613D3 for ; Wed, 21 Apr 2021 08:35:30 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0865A613D3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 79D8F6B0070; Wed, 21 Apr 2021 04:35:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 74D9B6B0071; Wed, 21 Apr 2021 04:35:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5EE836B0072; Wed, 21 Apr 2021 04:35:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 41CE36B0070 for ; Wed, 21 Apr 2021 04:35:30 -0400 (EDT) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 05CF91804E3D2 for ; Wed, 21 Apr 2021 08:35:30 +0000 (UTC) X-FDA: 78055715220.18.0816F42 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf28.hostedemail.com (Postfix) with ESMTP id A796B2000254 for ; Wed, 21 Apr 2021 08:35:31 +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 83531B143; Wed, 21 Apr 2021 08:35:28 +0000 (UTC) Date: Wed, 21 Apr 2021 10:35:26 +0200 From: Oscar Salvador To: Michal Hocko Cc: Andrew Morton , David Hildenbrand , Anshuman Khandual , Pavel Tatashin , Vlastimil Babka , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v9 3/8] mm,memory_hotplug: Factor out adjusting present pages into adjust_present_page_count() Message-ID: <20210421083525.GF22456@linux> References: <20210416112411.9826-1-osalvador@suse.de> <20210416112411.9826-4-osalvador@suse.de> <20210421080036.GC22456@linux> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Rspamd-Queue-Id: A796B2000254 X-Stat-Signature: o78wft8cakm9jiwdcd4zifnxoum39j33 X-Rspamd-Server: rspam02 Received-SPF: none (suse.de>: 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: 1618994131-532114 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 Wed, Apr 21, 2021 at 10:31:30AM +0200, Michal Hocko wrote: > > Given that {offline,online}_pages() is serialized by the memory_hotplug lock, > > I would say that {node,zone}->{spanned,present}_pages is, at any time, stable? > > So, no need for the lock even without considering this patch? > > Yes. The resize lock is really only relevant to the parallel struct page > initialization during early boot. The hotplug usage seems just a left > over from the past or maybe it has never been really relevant in that > context. Ok, I will prepare a follow-up patch to remove the lock in such situations when this work goes in. -- Oscar Salvador SUSE L3