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Wed, 02 Jun 2021 19:45:58 +0000 MIME-Version: 1.0 Date: Wed, 02 Jun 2021 21:45:58 +0200 From: Oscar Salvador To: David Hildenbrand Cc: Andrew Morton , Dave Hansen , Michal Hocko , Anshuman Khandual , Vlastimil Babka , Pavel Tatashin , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/3] mm,page_alloc: Use {get,put}_online_mems() to get stable zone's values In-Reply-To: <39473305-6e91-262d-bcc2-76b745a5b14a@redhat.com> References: <20210602091457.17772-1-osalvador@suse.de> <20210602091457.17772-2-osalvador@suse.de> <39473305-6e91-262d-bcc2-76b745a5b14a@redhat.com> User-Agent: Roundcube Webmail Message-ID: X-Sender: osalvador@suse.de Content-Type: text/plain; charset=US-ASCII; format=flowed Content-Transfer-Encoding: 7bit Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=UVlFEgG3; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=c7ryAEr6; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=UVlFEgG3; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=c7ryAEr6; dmarc=none; spf=pass (imf25.hostedemail.com: domain of osalvador@suse.de designates 195.135.220.29 as permitted sender) smtp.mailfrom=osalvador@suse.de X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 8CA576000157 X-Stat-Signature: pudsjcp3hj4wnmpb5czor7fdeorouf18 X-HE-Tag: 1622663145-234366 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000001, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 2021-06-02 20:37, David Hildenbrand wrote: > Long story short, using get_online_mems() looks wrong. > > Maybe the current lightweight reader/writer protection does serve a > purpose? It was too nice and easy to be true I guess. Yeah, I missed the point that blocking might be an issue here, and hotplug operations can take really long, so not an option. I must have switched my brain off back there, because now it is just too obvious. Then I guwmess that seqlock must stay and the only thing than can go is the pgdat resize lock from the hotplug code. Meh. -- Oscar Salvador SUSE L3