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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> MIME-Version: 1.0 In-Reply-To: <1ab6e58f-d984-4bae-a343-1b0d3c973ad0@kernel.org> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: DsLQwDhvyC3svmagsrf400Wj8C6vGc7AAcJa0ybzGO8_1776960791 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Rspamd-Queue-Id: 92A9FA0004 X-Rspamd-Server: rspam07 X-Stat-Signature: j9fjybq4dj6s4bgsy1ycqnidwihj44du X-Rspam-User: X-HE-Tag: 1776960795-975133 X-HE-Meta: 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 YhUgEHBV 7VFo9Ee8iJ+l53KWyZqnRpxPjwwpL5ViK5F5wuFuR75gqKA4/kun+1jlSFR1wXo1ARDSFCRLgg4BE6PjqmRxCkb4dMDrUJoPRmO1Kr/Lhs60OTdoYZ0gc4QUHFw9dNO0+4uwbGqjJPbX+NjlGlPIGtVoKHYj0tvFjBXXD5tNRV980Yrf/oNxwL2XDjnRqzabxHUc1pv1yrzf9aVg9RueAnmR4XnaLwZFvjzDjmNdnY0AUvEpYNF47OlyvzQmcI/bMvmTAZINDovtQTmJF82IiQl7w8TlNS9iGHtbyHLfvxcs56TGktKLUzlGBmCYRjR4reNQnyIYyVveGXK6/3WqWbDERrfgE+flUSqyKFdEAO5mdIDibLIonryGHPUAS0q2GV2G5WwWIt8jL9742NRAgw4ap/LA8E7WIX9cF0sEp80VAshjj4iQBKL0nwltRZUCYFQl368odMd6Qnww= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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