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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> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: Z6PcwtD4Wn9OoQ1kvarDybsu3egh2qCFVc4wpoxKIS0_1782767901 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Rspamd-Queue-Id: 9B41EC000C X-Stat-Signature: zkd8f874puskq46rjijh9ow8h4ez7e33 X-Rspam-User: X-Rspamd-Server: rspam03 X-HE-Tag: 1782767904-333881 X-HE-Meta: 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 SAUQZuhh BofLCnULMbZCiPo1ODWg+TKPvCzkvfBLhebbm/nFbUpsKW1nlmmujuJLtboygqqzR7ZiDLLKgpW4YEnvBBqM9Lmz1mKY3a9h+no/glkDPyLgfm0ZOTQprwmpfZp4UrDPKVxou853t2AkMy/ZoWpUBv4EOkctjTVc3kZ7sOFL9eqaD2yvQ/u99Qk5mxtSszo+1RhNRC8Jz/bbYx8cs5v2HOUGzl8gtVsiifmVo3EI3iUVzyvahChe02heC5Ulhgv6s0Jolm40kth8sohOn0HjjVJ/foWYumT2uYIUuNMpK6oZpLcFk+9qM3eYiyzecZgRMTfvYcuAL7sY7qp6TNjY1wlAhmGnc/A6P9Sy1ueXPcRhWtlJKXcm3R+9O/A== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: 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