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[80.230.48.7]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-45d9ed2f738sm7555351f8f.16.2026.05.14.08.47.20 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 May 2026 08:47:24 -0700 (PDT) Date: Thu, 14 May 2026 11:47:19 -0400 From: "Michael S. Tsirkin" To: Gregory Price Cc: linux-kernel@vger.kernel.org, "David Hildenbrand (Arm)" , Jason Wang , Xuan Zhuo , Eugenio =?iso-8859-1?Q?P=E9rez?= , Muchun Song , Oscar Salvador , Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Hugh Dickins , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Ying Huang , Alistair Popple , Christoph Lameter , David Rientjes , Roman Gushchin , Harry Yoo , Axel Rasmussen , Yuanchu Xie , Wei Xu , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , virtualization@lists.linux.dev, linux-mm@kvack.org, Andrea Arcangeli Subject: Re: [PATCH v7 02/31] mm: page_alloc: propagate PageReported flag across buddy splits Message-ID: <20260514114637-mutt-send-email-mst@kernel.org> References: <20260514104735-mutt-send-email-mst@kernel.org> <20260514113337-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: rvSMb44-P7Y3JjqfP__5qo4L4m0fWYpLSovSm2pGO-4_1778773646 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 19D9A18000B X-Rspam-User: X-Stat-Signature: 4h9k9dogcu6wbsteyoq9xn3zyai7osyy X-HE-Tag: 1778773648-401703 X-HE-Meta: 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 0HeHf6QB 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 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, May 14, 2026 at 11:41:45AM -0400, Gregory Price wrote: > On Thu, May 14, 2026 at 11:34:14AM -0400, Michael S. Tsirkin wrote: > > On Thu, May 14, 2026 at 11:32:26AM -0400, Gregory Price wrote: > > > > > > > > > > Maybe mildly out of scope but worth asking: Are there other flags that > > > > > should be retained/propogated on a split? If so, rather than pass > > > > > was_reported, should we just take a temporary copy of the page flags and > > > > > pass them all in? > > > > > > > > > > ~Gregory > > > > > > > > > > > > Not that I can see, no. > > > > > > > > > > You do this exact thing again later :] > > > > > > https://lore.kernel.org/linux-mm/9a22e0f9bbe1278913754db6df76e291a006181a.1778616612.git.mst@redhat.com/ > > > > > > ~Gregory > > > > I mean yes, reported and zeroed) Just zeroed does not exist at this > > stage in the series. > > > > More of a forward looking question: if we already know we're adding > was_reported and was_zeroed, maybe we should just pass the page flags > through entirely and let expand() check them instead of passing it > through individually. > > We end up doing something similar with post_alloc_hook later as well, so > I'm wondering if there's a general improvement that can be made here. > > ~Gregory sure, will do. do you want a bitwise thing for type safety? or just a long?