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Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <9C741BDB-31B0-460C-8FE7-F1C9B49002D5@hammerspace.com> References: <9C741BDB-31B0-460C-8FE7-F1C9B49002D5@hammerspace.com> <8F8B62FD-0F16-4383-BB34-97E850DAA7AF@hammerspace.com> <3DFBF27C-A62B-4AFE-87FD-3DF53FC39E8E@hammerspace.com> <20230316152618.711970-1-dhowells@redhat.com> <20230316152618.711970-28-dhowells@redhat.com> <754534.1678983891@warthog.procyon.org.uk> <809995.1678990010@warthog.procyon.org.uk> To: Trond Myklebust Cc: dhowells@redhat.com, Matthew Wilcox , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexander Viro , Christoph Hellwig , Jens Axboe , Jeffrey Layton , Christian Brauner , Linus Torvalds , "netdev@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , Anna Schumaker , Charles Edward Lever , "linux-nfs@vger.kernel.org" Subject: Re: [RFC PATCH 27/28] sunrpc: Use sendmsg(MSG_SPLICE_PAGES) rather then sendpage MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <3243439.1679490606.1@warthog.procyon.org.uk> Date: Wed, 22 Mar 2023 13:10:06 +0000 Message-ID: <3243440.1679490606@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.10 X-Rspam-User: X-Rspamd-Server: rspam03 X-Stat-Signature: h1hpbzs6e6r4hzkj6qnsyhkr674w7m16 X-Rspamd-Queue-Id: 2C4FE40009 X-HE-Tag: 1679490616-122886 X-HE-Meta: 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 7zJ6or4z xPdGdiDo01Tl8SHQEXBLS+YHuO++9dBVCkr5QhjbGfo8WGoPOpKo06KGrdbONMhYdghHRjCIkrgz2rgoICdk3faWZuBI47H1bVK9xi0MXuSgykoDGKkUMlkEv6M4VcxEJ7ghSfQ/mr+7kicia13DZZbj7ZnEp7B5GtbpS8opN35tdIor0HjioudJeMGq8kf6MXK6EpCrsQ5GUJmiha9vL36doKZ3ahvgCCkVqdf1JBRE/KcR6nFxOmaxkR5rxYs6lho2B5R0sm2n+ITWLR/qvH0tCQNRlq6/UJJ+IMxNOZjN1tXNfymyqhTr1+a33fcTRNLl9 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: Trond Myklebust wrote: > Add an enum iter_type for ITER_ITER ? :-) Actually, that might not be such a bad idea, now that I've pondered on it some more. Give it an array of iterators and add a flag to each iterator to say if it can be spliced from or not. Once ITER_PIPE is killed off, advancing and reverting over it should be pretty straightforward - though each iterator would also need to keep track of how big it started off as in order that it can be reverted over. David