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[80.230.85.71]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-30ee2f5ed29sm1122815eec.1.2026.06.29.14.18.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Jun 2026 14:18:19 -0700 (PDT) Date: Mon, 29 Jun 2026 17:17:55 -0400 From: "Michael S. Tsirkin" To: Andi Kleen Cc: "David Hildenbrand (Arm)" , linux-kernel@vger.kernel.org, Miaohe Lin , Naoya Horiguchi , Andrew Morton , Oscar Salvador , Hidehiro Kawai , Rik van Riel , Vlastimil Babka , Lorenzo Stoakes , "Liam R. Howlett" , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Brendan Jackman , Johannes Weiner , Zi Yan , Baolin Wang , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Christoph Lameter , David Rientjes , Roman Gushchin , Harry Yoo , Hao Li , Kiryl Shutsemau , Byungchul Park , linux-mm@kvack.org, linux-cxl@vger.kernel.org Subject: Re: [PATCH 0/2] mm: memory-failure: fix HWPoison flag race with non-atomic page flag ops Message-ID: <20260629171727-mutt-send-email-mst@kernel.org> References: <0b5f8b4b-d7dc-4b79-9555-a5b36265f3a9@kernel.org> <20260629030657-mutt-send-email-mst@kernel.org> <4f5ba5d6-246c-4430-9737-e8dd8e4c5142@kernel.org> <20260629092856-mutt-send-email-mst@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@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: On Mon, Jun 29, 2026 at 01:55:57PM -0700, Andi Kleen wrote: > > > Or if there are actually more performant alternatives that we could use. (I > > > still doubt that using atomics is ok in general) > > > > Right now I'm thinking of looking at something like stop_machine maybe. > > There can be (rare) cases where yoy get a lot of memory errors in a > flood. While memory-failure doesn't need to be particularly optimized, > it shouldn't be excessively slow or impact the rest of the machine. > > stop_machine is a big hammer that is likely to violate most of this. > > -Andi We can maybe batch a bunch of these, and do stop machine once? -- MST