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 3831EC61DB9 for ; Thu, 27 Aug 2026 15:57:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 4EC386B0088; Thu, 27 Aug 2026 11:57:13 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 49C536B0092; Thu, 27 Aug 2026 11:57:13 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 38BD16B0095; Thu, 27 Aug 2026 11:57:13 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 067226B0088 for ; Thu, 27 Aug 2026 11:57:12 -0400 (EDT) Received: from smtpin12.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 8824D140484 for ; Thu, 27 Aug 2026 15:57:12 +0000 (UTC) X-FDA: 85147503504.12.B764922 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf10.hostedemail.com (Postfix) with ESMTP id A83B4C000C for ; Thu, 27 Aug 2026 15:57:10 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=E8gjo2Rw; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf10.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1787846230; 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=CJD57KfG/QZ66WPVhOedT8gTIsjcNXLXXwCqIXIG4qc=; b=Soew2+4KlQwPswr1EggS2JREzIqWc759JPDpCJPykIHVA+RL3UavDRXJEfiFr9cv31tWlb DPyNKMIiNe8aAfxMwBo8ApxMNbQdR3e7vEjY4GTjbXCQqxsrutZfgAxaX3mtsNYKcaBLu9 Eb61Tq4x+jjeQUw1cjhjZ+xJigMKCO4= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=E8gjo2Rw; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf10.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1787846230; b=tCft2GQ57jnpHzgJz7qimY3xrC2H9z8ayIG7lQxqxodYmdZdzC7E0XOonGRXkEYz8IIWpF 6bs0Rw4IuA1tsGwEGZ2uGesKipBKFyV/Ijb7x1GKXZ3+I3Mi1LDdtVTn9Ee836n81DEpPc nkwa3RhoL4YSmWcAQ1iKkg1i/ExHatc= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id C287743CE6; Thu, 27 Aug 2026 15:57:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5AFED1F000E9; Thu, 27 Aug 2026 15:57:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787846229; bh=CJD57KfG/QZ66WPVhOedT8gTIsjcNXLXXwCqIXIG4qc=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=E8gjo2Rw096gGa06lttjTPVXYA/0357Xt78LUc6eDZqgcAwLSjD+wZOynLB3ozuU8 E2kq+RN0t8fsnysnZKtrszpNH2HS8RcuvXvxJB9DzyDLamEgXP3yXSi43Rtrrfci2c xT3/aqIiGNAbd4eQtbTiPkXAGuKaBAQiC5Q/qJOeoPbzM7uKT4n3AQdfrg8LlmfOu8 V9GM3Q1uXNOPRmMQ6aCroV5zR/jf331cB9E2ZawOIpMz1WLuRjYkwCu8IBoEE6yNSm r/tZV5Zxk51Aqce3ABeh4pnBXKa4x72EG2/hUECPwL+zIEeeOd0oJHh/fx6+pOSfH3 pbM0eR7OCvoJw== Message-ID: Date: Thu, 27 Aug 2026 17:57:01 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 01/18] mm/swap: fix off-by-one in swap cache replace sanity check To: kasong@tencent.com, linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Andrew Morton , Lorenzo Stoakes , Zi Yan , Baolin Wang , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Chris Li , Kemeng Shi , Nhat Pham , Baoquan He , Barry Song , Youngjun Park , Shivam Kalra , Kairui Song References: <20260821-swap-thp-cleanup-v3-0-9b43f5163238@tencent.com> <20260821-swap-thp-cleanup-v3-1-9b43f5163238@tencent.com> 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: <20260821-swap-thp-cleanup-v3-1-9b43f5163238@tencent.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: A83B4C000C X-Stat-Signature: bqfry6jptafzq44d8srb1ztq5rxp5mzs X-Rspam-User: X-HE-Tag: 1787846230-475433 X-HE-Meta: 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 R+h8pS7S 3obnejCwkzs6bOcTctcX6o3so7C52V8XT5R7yIGu4YpIrUFPCZgHtuAmFdPV3jEM6cz2TZPFq3OrXokzzle0etQZh5+2oBuzNBkmTmxQTBMNZAkiPqR5QLufOf5a8nUAnUg6Odx0HafGpEWCsPfVUCrCAwiBO9kXQXGENQuYwNsaZXbk7/5rmQNBUdhCWJuCXEpb5eW7JmfhpHOqn3fNYzAJ5D0xf5BGmKI2Keqggdl6mbwG3MqjBFYmeDputXCAq2cIIsnmy0WeZNLd3elxiUVVUAJH2Z5lf1JD2XKBQg/SQOsuPy/EN3Mtabl0XW1PE2zG6fQH+GpMvv/0= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 8/20/26 20:55, Kairui Song via B4 Relay wrote: > From: Kairui Song > > The DEBUG_VM sanity check in __swap_cache_replace_folio() iterates > the old folio's range with "while (ci_off++ < ci_end)", so the loop > body runs on the already-incremented offset: the first entry is > skipped and one entry past the range is read. For a folio split > that entry belongs to the first after-split folio and was just > repointed by the replacement loop above, so the check would warn > spuriously whenever sub-folio orders differ from the head folio's, > as non-uniform swapcache splits now do. > > Use the same do-while pattern as the replacement loop. > > Fixes: 8578e0c00dcf ("mm, swap: use the swap table for the swap cache and switch API") > Acked-by: Zi Yan > Signed-off-by: Kairui Song > --- Acked-by: David Hildenbrand (Arm) -- Cheers, David