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[80.230.25.21]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4891cdfcd50sm122342895e9.9.2026.04.23.09.13.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 23 Apr 2026 09:13:09 -0700 (PDT) Date: Thu, 23 Apr 2026 12:13:03 -0400 From: "Michael S. Tsirkin" To: "David Hildenbrand (Arm)" Cc: Gregory Price , linux-kernel@vger.kernel.org, Andrew Morton , Vlastimil Babka , Brendan Jackman , Michal Hocko , Suren Baghdasaryan , Jason Wang , Andrea Arcangeli , linux-mm@kvack.org, virtualization@lists.linux.dev, Johannes Weiner , Zi Yan , Lorenzo Stoakes , "Liam R. Howlett" , Mike Rapoport , "Matthew Wilcox (Oracle)" , Muchun Song , Oscar Salvador , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Ying Huang , Alistair Popple , Hugh Dickins , Christoph Lameter , David Rientjes , Roman Gushchin , Harry Yoo , Chris Li , Kairui Song , Kemeng Shi , Nhat Pham , Baoquan He , linux-fsdevel@vger.kernel.org Subject: Re: [PATCH RFC v3 01/19] mm: thread user_addr through page allocator for cache-friendly zeroing Message-ID: <20260423121222-mutt-send-email-mst@kernel.org> References: <9dd9deabd42801f3c344326991d1431c3d8db39d.1776808210.git.mst@redhat.com> <20260422171315-mutt-send-email-mst@kernel.org> <20260423074433-mutt-send-email-mst@kernel.org> <88b0765f-7cfc-4e44-83d2-c01a1755c842@kernel.org> <20260423104120-mutt-send-email-mst@kernel.org> <1ab6e58f-d984-4bae-a343-1b0d3c973ad0@kernel.org> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <1ab6e58f-d984-4bae-a343-1b0d3c973ad0@kernel.org> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: 0JRczrtgJA8lzPNJNMmVuGc6BBPOIzrtfNjMLmhGC9k_1776960791 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Thu, Apr 23, 2026 at 05:54:26PM +0200, David Hildenbrand (Arm) wrote: > On 4/23/26 16:46, Michael S. Tsirkin wrote: > > On Thu, Apr 23, 2026 at 04:13:50PM +0200, David Hildenbrand (Arm) wrote: > >> But really, that hugetlb code is rather messy. I'd vote for leaving hugetlb > >> alone on a v1, and focusing on non-hugetlb first. > > > > I just dislike it when things are non orthogonal. > > People are used to: hugetlb = same perf as THP but more predictable at the cost > > of being harder to use and using more resources. > > Here, suddenly, we have an optimization but only for THP. > > Note that we also didn't care about user_alloc_needs_zeroing() with hugetlb so far. You mean, that it stays because of the reserved pool? > It's not that it cannot be done with hugetlb, it's just a question about how it > can be done more cleanly; and that requires more work to clean the hugetlb part up. > > Best done separately. > > -- > Cheers, > > David