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Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <3351099.1675077249@warthog.procyon.org.uk> To: John Hubbard Cc: dhowells@redhat.com, Jens Axboe , Al Viro , Christoph Hellwig , Matthew Wilcox , Jan Kara , "David Hildenbrand" , Jason Gunthorpe , "Logan Gunthorpe" , Jeff Layton , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [GIT PULL] iov_iter: Improve page extraction (pin or just list) MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <3520517.1675116740.1@warthog.procyon.org.uk> Date: Mon, 30 Jan 2023 22:12:20 +0000 Message-ID: <3520518.1675116740@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.3 X-Rspamd-Queue-Id: 152A5180018 X-Stat-Signature: 3af3jmbycf98xoota6mioh6rqu5nihuw X-Rspam-User: X-Rspamd-Server: rspam08 X-HE-Tag: 1675116749-762826 X-HE-Meta: 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 0YAxU88s tNtcnOdVmUKmLIGlct5bztQVhissPT0ImZiZsf65hN3j4Gl+PWhvk5DP0GD/VROx5B9slcmC9kFWcwnkQvs2ksRuL/s5RV8DVDHVCEkof05Se/L5pFcT2ndzrNI5PpGQlway5YulF/P+tfxlnHE1qWm1YLyK9HSiSxSktE7o5ccnJH+PNLRzR2Vsbh6aO3KJyvECpn+RrudMHbnrNRuR6o5ujfPXWQAwY1ckQzeQVuM88m1tOIIMLuGTc9g== 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: John Hubbard wrote: > This is something that we say when adding pin_user_pages_fast(), > yes. I doubt that I can quickly find the email thread, but we > measured it and weren't immediately able to come up with a way > to make it faster. percpu counters maybe - add them up at the point of viewing? David