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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Andrew Morton , Yuan-Hao Hsu Subject: Re: [PATCH v3 5/6] mm: gup: introduce gup_unshared_pages() Message-ID: References: <20261109-refactor_gup_fast-v3-0-2aaef02df0e1@arm.com> <20261109-refactor_gup_fast-v3-5-2aaef02df0e1@arm.com> <7627c0d90188b581e7740bf8d17c8dd07b460f89.camel@surriel.com> <699499e46ace0875fd0f32052399e665c8209ea9.camel@surriel.com> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <699499e46ace0875fd0f32052399e665c8209ea9.camel@surriel.com> X-Stat-Signature: pjepdurusmfxrimu6tt1s6q113gpy7wt X-Rspamd-Queue-Id: 148661C0009 X-Rspam-User: X-Rspamd-Server: rspam11 X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=no autolearn_force=no version=4.0.1 X-HE-Tag: 1794341981-912704 X-HE-Meta: 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 zadrazWR EKy2oR7IOGIS2mYw5BOvL7Wvzps8FjufqpxdEBLP2mUVeqbaEVgA1f9ThrEauTlYSySQIg+wn6Rd0MZajSGh8xUqsczx5KsW0FCytSbQiBI85dmfSXfSgWLUClo5AXery0+EZhcxpuC96NkcvdhHsyz2D6EXJ5yFr/rZp4bEnxwkI7Abvz7HEuP4VAmm52bu8aTgGTu6QNlpF5+9Grjnm1FW85S+XUAFqaO8pt2pAypIVYf5Vq562H/zU/4mR/IeJ5WhnjFsqPVOnRRreskOJAChwv6v/wR/RsuTD Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Tue, Nov 10, 2026 at 02:21:18PM -0500, Rik van Riel wrote: > On Tue, 2026-11-10 at 14:04 +0100, David Hildenbrand (Arm) wrote: > > On 11/10/26 10:58, Yeoreum Yun wrote: > > > Hi Rik, > > > > > > > On Mon, 2026-11-09 at 12:32 +0000, Yeoreum Yun wrote: > > > > > This is preparatory patch to make gup_fast_pte_range() > > > > > batchable. > > > > > > > > > > Introduce gup_unshared_pages() to count consecutive pages > > > > > within a > > > > > folio > > > > > that do not require unsharing, and use it to implement > > > > > gup_must_unshare(). > > > > > > > > > Could gup_exclusive_pages() be a better name? > > > > > > Yes. This seems much better for me. I'll change it in next-spin. > > > > Not quite the right semantics. For pagecache folios we simply don't > > need > > unsharing in MAP_SHARED VMAs. That does not imply that these are > > exclusive. > > > > So it's all about "number of pages that don't need unsharing". > > > gup_no_unshare_len() ? > > a little awkward sounding, but it describes > what it's doing? Hmm, Wouldn't this name be semantically much the same as keeping the existing gup_unshared_page(), since both essentially convey that no unsharing is required from GUP's perspective? Anyway, naming is always NP-hard problem :\ -- Sincerely, Yeoreum Yun