From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F1D5DC43458 for ; Wed, 1 Jul 2026 08:36:44 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E00476B00AF; Wed, 1 Jul 2026 04:36:43 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id DD8B16B00B0; Wed, 1 Jul 2026 04:36:43 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CC6E66B00B1; Wed, 1 Jul 2026 04:36:43 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id A99F36B00AF for ; Wed, 1 Jul 2026 04:36:43 -0400 (EDT) Received: from smtpin29.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay10.hostedemail.com (Postfix) with ESMTP id 31625C15E6 for ; Wed, 1 Jul 2026 08:36:43 +0000 (UTC) X-FDA: 84939551886.29.80A5CB4 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf25.hostedemail.com (Postfix) with ESMTP id 6C6F1A0005 for ; Wed, 1 Jul 2026 08:36:41 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b="jzW/rrzw"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf25.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1782895001; b=v/D2q8LSkfXlFrKlslel32zSmZdZk9U6ORmagV1vPld867KhHtx+iP240yY6kOfAm3Pssw cV5ZmQyhm+mYHqSyxnowIxkzVUsGhE7GIoa8ZNbA74o5VE0fEWN9SXZ9wxyuzoHhb3gsDr 8kP9+hodnPhspa2gbPMt66u0tvR4guk= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1782895001; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=xPEJAHy4hb00HRqDPAQWbFJl4HuP8MOTJH/+eoezJ7I=; b=g8FsCmcZaTSrd+QAAU94jqKALLbzxEI7McFY/QpWNZlXMHnVN4dPopyzb4Ap7b0eq1QoDa 3O8Me8wiacW+Q9m7HmIkb+GaWrfRJM3tKvXd7LraCfREs9CCiC3d9vN0Yao1lzn/AiAquE N8bnSmDWvRXZ6KPG8dRT1/GBenM14+g= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b="jzW/rrzw"; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf25.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id F1A8C6001D; Wed, 1 Jul 2026 08:36:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 371091F000E9; Wed, 1 Jul 2026 08:36:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782895000; bh=xPEJAHy4hb00HRqDPAQWbFJl4HuP8MOTJH/+eoezJ7I=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=jzW/rrzwTr0czj4QnvDVZj4wh8o8DkAXTIMba4+v3umaXcz2XyBShEeJaunOpw7oJ c62tiaBrta2dD+rFE1Mvn0I/QqPtJn6btwSICosFH2epy6HfAUHFIEoygUUEi5lV3a 48/5zbISrWpdxErC1ygFmRBoOzmbkNwEo/2si6aJLrHouWoG0Ay6dp0M+l4IKonbwK Vly83+W/tyxp2abFNlcl2m9+TZKljikrsMtK3DpXQfbe0s52A/SXRBDT/EytnagoVN 0e9ewkvbyVLx3gJDBL/JaZhpzx8irrSv3t7msktUZXNAi5N03ReL0AoULRrW+PcywP 1ZLEdArRC3XUA== Message-ID: Date: Wed, 1 Jul 2026 10:36:31 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 0/2] mm: memory-failure: fix HWPoison flag race with non-atomic page flag ops To: "Michael S. Tsirkin" Cc: linux-kernel@vger.kernel.org, Miaohe Lin , Naoya Horiguchi , Andrew Morton , Oscar Salvador , Andi Kleen , 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 References: <4f5ba5d6-246c-4430-9737-e8dd8e4c5142@kernel.org> <20260629092856-mutt-send-email-mst@kernel.org> <54c8cbee-9b26-458c-93ba-5aa594f5d1e8@kernel.org> <20260629174225-mutt-send-email-mst@kernel.org> <20260630174852-mutt-send-email-mst@kernel.org> <2f884bfa-3cd5-4fba-8aa4-c2e68890ab64@kernel.org> <20260701041112-mutt-send-email-mst@kernel.org> <20260701043024-mutt-send-email-mst@kernel.org> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20260701043024-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: 6C6F1A0005 X-Stat-Signature: awbubgctkb8a1dfu34sh4piqxpkpqm5x X-HE-Tag: 1782895001-452024 X-HE-Meta: U2FsdGVkX18tM9aQsDmXoHCNf+R7rZBzB/R63+yvv/oxYfxgNreVfqjuINZwLY58rwhpeVzlF2Lpsjl9wi9lQ1oDgaQNkT3kph7558OnttoHUY9nH+Mm96WvRTys+jKSC7C8WA+G9h34qeNgMAql8eVtvSg36eWPtcWjDpVHQLMswaRSsn0ja8u+8yjIBQQz49yUcDVq61qbRm2/ryquFpngCILij+ZWiPB9/+A/7imoifyJbOjbvCcUJ+3Grh8kFrzeWUXIBLeBKSaVAe8bnR2k3KZWRMeHNWHlVgNztJ0nvtI73X//C7HAzP/6FsJ24unTdODVkhU7N0Cf0CzgQkwS1+YLyOGdmui1kuPB1dqrJjPwYXAuRYi66kEPAcFcBzBoiPAWe0p3U7xfQIDRffETj9sA4wjfi79eNPupauOIWxY3ebuQu1dlxcIXz4rqM8J/R/rrvbgPyP9/Imom5i3RkNY19VHev2EFkm4ElgQlwf/4qPKqPnJw4pKQ/8U9tAJHjjiJiHwD5m3KK8ssIHl/LJFnJddNXhPY/ik59OsN0uIBaT/Dkrn5XSHEkd/KoFdaNgqsy496p52Hp/t8lCCkSUxXwjFWo0ttT4DUsJWnaWnqjnQkxYhc0oXPoV6844FJKUks0wml/yHXwn8e0+8BRjDXUxIEQaJFN0WkAZHIxYXQgNy2hWT9fn6CibT9hnZF+ODefDuBKMmB+3H9nkktK9bVHzEWaPnz9Bx5mq62f7OaeIilJ4xlgUaWNY4UdRRPMazaAdX0c/ei+MkN3g/ZwWvn1pEkfOEXPWFx1PhzQ1mJ1stXF6KCogHdvJDzeHVjdXj5DxSvgc44BqWuLUxuPdBaRpxjGiHn1iHNkfRxNJxrOZuca2PqguouPse8X4UrDCkfzpMKw3/VpFLu2eieH8DGgZEgRqBMx5TBcneaXk3p5TMyqKT6mRTYRjbPkzhs+sABHgSS3jT7PYz gbn1fh7u l4lTlRAzRezac9LGxfVzXkRD0GVpd1V7B5dTXdMk1m4T5Ei0npVnD6A6cFmiKaKqre4PZlPOZwNoJl1yXNZ7dmVbPnRfIFXVB8JxXKSIW8nWBwmZS40Hn0W7Lj/K7KerNq+zHHgM/7xdYJiF7WurzIKYGINYSTr0bkZyfl966BGIwgOoqYWVR4jtbG8yN4hBZea+XYUOdU8aGJIqe5aXyBp6P8MTSx+mNWzbW6wqz1gDnLCddbPZjGt4JjKZIiXrptilVFAS57TiS0hes75MBAlS2riMf31gX6RLe5CsEkDmOwS1NHkZm0kNGuOkWHfVR9KMYqmSa9dyyE8lOLuz5+59/3w== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 7/1/26 10:33, Michael S. Tsirkin wrote: > On Wed, Jul 01, 2026 at 10:26:26AM +0200, David Hildenbrand (Arm) wrote: >> On 7/1/26 10:18, Michael S. Tsirkin wrote: >>> >>> So on this idea. It might not matter. What I had in mind is: >>> 1. run the current logic >>> 2. add page to a list of pages to check, then invoke e.g. call_rcu_tasks >>> (or call_rcu_tasks_rude) maybe >>> 3. in the callback, recheck and if poison cleared, go back to 1 >>> 4. otherwise everyone will see the bit set, remove from list we are done >>> >>> it seems to not regress anything, and for the rare race, we set >>> the bit eventually. >>> >> >> So test-and-set (and friends) would also have to check the data structure that >> remembers bit to set/clear (and possibly update the data structure). >> >> That does seem doable. Do you have a prototype? > > what do you think ;) post it? As RFC please :) [and if it's AI generated, obviously properly reviewed and reworked by you] -- Cheers, David