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[80.230.85.71]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-30ee2fc12e7sm1126539eec.8.2026.06.29.15.00.00 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 29 Jun 2026 15:00:18 -0700 (PDT) Date: Mon, 29 Jun 2026 17:59:55 -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: <20260629175638-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> <20260629171727-mutt-send-email-mst@kernel.org> MIME-Version: 1.0 In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: PEEbrvHfrJFoBWwV5Y695riqdP_oAT3_VQD_qaikZsI_1782770420 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Rspam-User: X-Stat-Signature: x6qpcu3s6c65t7dg34rwf43fhgrgc13o X-Rspamd-Queue-Id: 6DAE4A0010 X-Rspamd-Server: rspam06 X-HE-Tag: 1782770423-290302 X-HE-Meta: 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 QzGKdJSv BQWVl1igzPpo9xAOr46yTGxA5Cs3OhH5+ovJYneeFnhbgbbJZX6N59KZcSfuVY4H1Xv95vbm6qxvWIjIBtZDqoPTyaR8g0LpbB6BtKenKqJ8JLaAigAk4VEh723ZLTmREcgJaAl3KhrzlHc+FMFHA4NY/2upGaNHBCic15O8colXgTCVZJ0kOF8LNsWuZAZ80TRtBj8YsLzJcVHvNAehMf4xK7sOkmKfAuAtYDRC/xZipxgr9c8ZKCGHFzWQ9Ojra44mojFNS34N8jYZWo6rsqVcOsV8R4vy43bXzfrsI8jopFxG7UD+oH/DW5hq3VM5h4X5nZMRx41ks2dGCF0R+BbyQ7r6tfDQ0XMFSIZyauHoU6Qxh9hJ7r8ROomPshGg9vrtKoWZKxC2g0rU= 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 02:39:44PM -0700, Andi Kleen wrote: > > We can maybe batch a bunch of these, and do stop machine once? > > If you add a long delay you increase the risk that the machine or > the critical process dies because there is an unrecoverable or > process killing AR access before the page can be off lined. Well nothing prevents us from opportunistically running the MF machinery once first of all. No regression then? We then add it to a batch and once the batch is full we do stop machine and reprocess them again. Hmm? > > (BTW that's a problem even with the RCU approach, the cure might be > worse than the disease) > > If you don't add a long delay you would do a lot of stop machines > on a flood, likely bringing it to a halt, even though other sockets etc. > might still be fine. > > -Andi