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[96.255.20.138]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-4eba386b6b9sm71298341cf.33.2025.10.28.06.09.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 28 Oct 2025 06:09:04 -0700 (PDT) Date: Tue, 28 Oct 2025 09:09:01 -0400 From: Gregory Price To: Jason Gunthorpe Cc: Lorenzo Stoakes , David Hildenbrand , Andrew Morton , Christian Borntraeger , Janosch Frank , Claudio Imbrenda , Alexander Gordeev , Gerald Schaefer , Heiko Carstens , Vasily Gorbik , Sven Schnelle , Zi Yan , Baolin Wang , "Liam R . Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Kemeng Shi , Kairui Song , Nhat Pham , Baoquan He , Chris Li , Peter Xu , Matthew Wilcox , Leon Romanovsky , Muchun Song , Oscar Salvador , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jann Horn , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Ying Huang , Alistair Popple , Pedro Falcato , Pasha Tatashin , Rik van Riel , Harry Yoo , kvm@vger.kernel.org, linux-s390@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [RFC PATCH 05/12] fs/proc/task_mmu: refactor pagemap_pmd_range() Message-ID: References: <76348b1f-2626-4010-8269-edd74a936982@lucifer.local> <3f3e5582-d707-41d0-99a7-4e9c25f1224d@lucifer.local> <20251027161146.GG760669@ziepe.ca> <27a5ea4e-155c-40d1-87d7-e27e98b4871d@lucifer.local> <20251028125244.GI760669@ziepe.ca> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20251028125244.GI760669@ziepe.ca> On Tue, Oct 28, 2025 at 09:52:44AM -0300, Jason Gunthorpe wrote: > On Mon, Oct 27, 2025 at 04:38:05PM +0000, Lorenzo Stoakes wrote: > > The union helps encode in the type system what code is operating on > what type of the leaf entry. > > It seems pretty simple. > My recommendation of a union was a joke and is anything but simple. Switching to a union now means every current toucher of a swp_entry_t needs functions to do conversions to/from that thing as it gets passed around to various subsystems. It increases overall complexity for no value, i.e. "for negative value". Please do not do this, I regret making the joke. Regards, Gregory