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Tue, 11 Mar 2025 22:55:13 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id ADdaLlG/0GevaQAAD6G6ig (envelope-from ); Tue, 11 Mar 2025 22:55:13 +0000 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit MIME-Version: 1.0 From: "NeilBrown" To: "Gao Xiang" Cc: "Yunsheng Lin" , "Yunsheng Lin" , "Dave Chinner" , "Yishai Hadas" , "Jason Gunthorpe" , "Shameer Kolothum" , "Kevin Tian" , "Alex Williamson" , "Chris Mason" , "Josef Bacik" , "David Sterba" , "Gao Xiang" , "Chao Yu" , "Yue Hu" , "Jeffle Xu" , "Sandeep Dhavale" , "Carlos Maiolino" , "Darrick J. Wong" , "Andrew Morton" , "Jesper Dangaard Brouer" , "Ilias Apalodimas" , "David S. Miller" , "Eric Dumazet" , "Jakub Kicinski" , "Paolo Abeni" , "Simon Horman" , "Trond Myklebust" , "Anna Schumaker" , "Chuck Lever" , "Jeff Layton" , "Olga Kornievskaia" , "Dai Ngo" , "Tom Talpey" , "Luiz Capitulino" , "Mel Gorman" , kvm@vger.kernel.org, virtualization@lists.linux.dev, linux-kernel@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-erofs@lists.ozlabs.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, netdev@vger.kernel.org, linux-nfs@vger.kernel.org Subject: Re: [PATCH v2] mm: alloc_pages_bulk: remove assumption of populating only NULL elements In-reply-to: <316d62c1-0e56-4b11-aacf-86235fba808d@linux.alibaba.com> References: <>, <316d62c1-0e56-4b11-aacf-86235fba808d@linux.alibaba.com> Date: Wed, 12 Mar 2025 09:55:10 +1100 Message-id: <174173371062.33508.12685894810362310394@noble.neil.brown.name> X-Rspamd-Action: no action X-Rspam-User: X-Rspamd-Queue-Id: 97CF8140009 X-Rspamd-Server: rspam03 X-Stat-Signature: hqyncz3c8ym979jkk1gnuz3wr5nj86sc X-HE-Tag: 1741733730-934561 X-HE-Meta: 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 iwVggEY4 5MXjyfZhc38t16X1WUs5YStnbhVL+yIR/eWfMA77T3n3iIakOe8BqEzu3TrwAwzsv41XmSAqg1r8Be/P1hySjMHp+/hHVIiDV3GqTvOd+oUGegWkuuwwREd1NSykirzUjvCJsrD0J6ad18vCv7Vke1Ut5+X7/KM5UyDOV8r9PpwBSZSUdtY2I8wz0Z03uioQPEMrWx/BFcFirMDsjLhGTxxTjI6NaeG0ome+/szvP83uIZQtIa21snVr+pc0AcHdNtJC0WYmkI1+fT+jhTqHMnoq7pNldMO1mG66pZJ8+bshvjiK7OxVwmVorSJmIGdsfVJT3iALTWUN2ujwWxOYwOBkmiQ== 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: List-Subscribe: List-Unsubscribe: On Mon, 10 Mar 2025, Gao Xiang wrote: > > - Your new api covers narrow cases compared to the existing > api, although all in-tree callers may be converted > properly, but it increases mental burden of all users. > And maybe complicate future potential users again which > really have to "check NULL elements in the middle of page > bulk allocating" again. I think that the current API adds a mental burden for most users. For most users, their code would be much cleaner if the interface accepted an uninitialised array with length, and were told how many pages had been stored in that array. A (very) few users benefit from the complexity. So having two interfaces, one simple and one full-featured, makes sense. Thanks, NeilBrown