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Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Pedro Falcato , "Matthew Wilcox (Oracle)" , Jan Kara , Miaohe Lin , Naoya Horiguchi , Rik van Riel , Harry Yoo , Lance Yang , Kees Cook , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Usama Arif , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Gregory Price , Ying Huang , Alistair Popple , Peter Xu , Xu Xin , Chengming Zhou , Arnd Bergmann , Greg Kroah-Hartman , linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v3 07/15] mm/rmap: track whether the page VMA mapped pgoff is anonymous Message-ID: References: <20260729-b4-scalable-cow-virt-pgoff-v3-0-e8ecfefea812@kernel.org> <20260729-b4-scalable-cow-virt-pgoff-v3-7-e8ecfefea812@kernel.org> <1b48cf7d-8906-43d4-a85d-5cfad10a12ac@kernel.org> <007258ed-3fd7-4d90-b909-6fdda15e0485@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Queue-Id: 52E0E1A0007 X-Stat-Signature: e56ipqrcmzm5zzb9zy5ioefmj6tj8oab X-Rspam-User: X-Rspamd-Server: rspam04 X-HE-Tag: 1785914741-722165 X-HE-Meta: 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 Rl96Bqmr BOHw2tvOD0ipxGMmMSK3zI/91+7Nv9/Umz6/Ylm0YGankcQm8WJjrAxkUUcLAEBd1vjFf2xW6dxJHzfsVT1VacRVvch1W4dtRICUP0hI+f+LaRIYfKHNL3tTtwEWgHLmneiRAMzkRf06nOH+1jf8YHqQXyO/OwAjOO+6oFWmPMMzgiDGZjS41ffoNu0LbhSUVMUndW3FfXqrNyj28lZTkeNaoi9s0PjT53Pc/xnqIFM2it6qBtSB2D67giBpzhfm4vWqAw3ojc4RrfFGXhlORQdxGMzU7HrVpgizbSm03gDqSIHuukSPIWscHdcEyerfGP44+CbHPsbcPfPc= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed, Aug 05, 2026 at 09:17:26AM +0200, David Hildenbrand (Arm) wrote: > On 8/3/26 16:32, Lorenzo Stoakes (ARM) wrote: > > On Mon, Aug 03, 2026 at 04:02:45PM +0200, David Hildenbrand (Arm) wrote: > >> On 8/3/26 15:51, Lorenzo Stoakes (ARM) wrote: > >>> > >>> As per commit message: > >>> > >>> This is laying the groundwork for eventually using anonymous page offsets > >>> as the index for all anonymous folios. > >>> > >>> No functional change intended. > >>> > >>> I cannot enable an effective change here, because if I did I'd break the kernel > >>> and introduce a bisection hazard. > >> > >> You can just throw in a patch that cleans that up and avoids messing with confusing pgoff? > > > > You mean do a separate patch for this change? > > > > The existing code is already very confusing :) it becomes worse with the > > anon stuff added, hence the change. > > > > I will separate it out assuming this is what you mean? > > Right, if the vma_address_end() is not required in this patch (and does not fall > under "track whether the page VMA mapped pgoff is anonymous"), just have it in a > separate cleanup patch "prepare vma_address_end() for further changes" etc. Cool, will do! > > -- > Cheers, > > David -- Cheers, Lorenzo