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[100.36.248.188]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-5148e83dd35sm121584711cf.29.2026.05.12.08.40.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 12 May 2026 08:40:11 -0700 (PDT) Date: Tue, 12 May 2026 11:40:08 -0400 From: Gregory Price To: "Michael S. Tsirkin" 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 resend v6 17/30] mm: page_alloc: propagate PageReported flag across buddy splits Message-ID: References: <6d98a35c94fa44b550afa66923c620511e2826f0.1778489843.git.mst@redhat.com> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6d98a35c94fa44b550afa66923c620511e2826f0.1778489843.git.mst@redhat.com> On Mon, May 11, 2026 at 05:03:19AM -0400, Michael S. Tsirkin wrote: > When a reported free page is split via expand() to satisfy a > smaller allocation, the sub-pages placed back on the free lists > lose the PageReported flag. This means they will be unnecessarily > re-reported to the hypervisor in the next reporting cycle, wasting > work. > Is this issue generated by the changes in the overall patch set, or an issue present regardless of the proposed zeroing avoidance feature? If the former, then maybe just submit as a standalone patch, seems like a useful improvement regardless. If fundamentally tied to the zeroing-avoidance feature, then nudging this to the front or end of the series (depending on conflicts) would help focus the review of the core new feature. ~Gregory