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 C3B7EC55174 for ; Wed, 5 Aug 2026 10:03:32 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B1B2F6B00A0; Wed, 5 Aug 2026 06:03:31 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AF40D6B00A1; Wed, 5 Aug 2026 06:03:31 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A09566B00A3; Wed, 5 Aug 2026 06:03:31 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id 77DC26B00A0 for ; Wed, 5 Aug 2026 06:03:31 -0400 (EDT) Received: from smtpin13.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 109F61603D2 for ; Wed, 5 Aug 2026 10:03:31 +0000 (UTC) X-FDA: 85066778622.13.A9DA6DA Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf09.hostedemail.com (Postfix) with ESMTP id 52991140009 for ; Wed, 5 Aug 2026 10:03:29 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=S3W2w0pT; spf=pass (imf09.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1785924209; 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=MwtspZMnFWA7BsVmyrJkIUlpBk6kNAmUxfeVp4Cf1pc=; b=tDBKlRSzIL1is+/irPeQtdDnDVOk31OxDYQiCagtOVG60gwoz7mCscQWniUEJOaj2lIrSy /FdMh+v6tRytShqAVWoVAmybPPNeja4q5huT7XjHcNR5k2KRY4krtBFkGd6zGf3mtF5p9E cxLVRLMOUQRHg6NVdlHmnKESYmGQjVI= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1785924209; b=haSB06yu3MIQ0s8EpftpNLRgsgj4IiX8G3rGcZHo/scttmR27R0FrRtLpKIgYNLF4jJbTR NwEI0Pqms5nR33T66PjonJIqfv7lH5wyK6Ba6qGL4f0zEwtpEwH5yaWJYuSD8nX7ZapxXf pDCKDURKp+7Fr2YEKKIS9gKf3enk9K0= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=S3W2w0pT; spf=pass (imf09.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id BBC8D600AE; Wed, 5 Aug 2026 10:03:28 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E8C01F00A3D; Wed, 5 Aug 2026 10:03:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1785924208; bh=MwtspZMnFWA7BsVmyrJkIUlpBk6kNAmUxfeVp4Cf1pc=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=S3W2w0pT4H9XaHeVc3HvSp4e6zheDeu7X5ZWPFNNRqiiuueGH06xDeAlFmnXdk3db HrShB7eMwOiofu4VTNY3lo12/kxB9fV02xBLwAvZjbOeULv9ajKJeSucjVcYCqsGEd crmHKxHiV3483alYvtccbiz8IBY3AHXoH05eHAIa2e6d9KJmdyCzE/pBFXMF9KBCWx MTD/30gGuw2TGcbGRP3iK6B1/bnno+pGQH6S8834/XWtpKmTdZ1OjL8GJLEJ078ium Tv/DIFkxBXEVT1i/YkmBMO/cSRmcHCIXOVEiLT7oVKOlnkOqdxf63j/oSrhgisMMuE Xf1XlyNHZcT5w== Message-ID: Date: Wed, 5 Aug 2026 12:03:24 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v2] mm/memory-failure: fix concurrent access issue in min_order_for_split() To: "Lorenzo Stoakes (ARM)" Cc: dayou5941@163.com, akpm@linux-foundation.org, ziy@nvidia.com, linux-mm@kvack.org, liyouhong , Sashiko , stable@vger.kernel.org References: <20260805072625.2437636-1-dayou5941@163.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: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 52991140009 X-Rspamd-Server: rspam10 X-Rspam-User: X-Stat-Signature: c89pa7biqj1szgojdprzondc6m74fruu X-HE-Tag: 1785924209-601808 X-HE-Meta: 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 4uybwEkZ j64kwmqumKzewcb0VNxqNE+EjF7os8XJIwgO2+8L/SmHYiW8vp8/s2+OrhWS43sJDwIdgtZgzuTgxrA7m+IyLoBe+AkVeOXFTxJKMOlPZV0acoBBHdmhUtETCHB+fU8uFVp3bTw/drchuzMfAJs0SVgtJ7p5f7o/wopNXtZt+/iRUyMK358DrSpQtbWV2KyonJ8HWgQdwsThow2qbcX2COii17uw4PPCtv5hpyu7x9Gf5dZI5pFEyRXuHchplBKkL3t4jI0C6VW3HSlmNlA44M+kqxlJxHwfDCpIflOnZlc3aAbdFmV/ZDmyI2w== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: >> /* >> @@ -2862,8 +2841,7 @@ static int soft_offline_in_use_page(struct page *page) >> }; >> >> if (!huge && folio_test_large(folio)) { >> - const int new_order = min_order_for_split(folio); >> - >> + lock_page(page); >> /* >> * If new_order (target split order) is not 0, do not split the >> * folio at all to retain the still accessible large folio. >> @@ -2871,8 +2849,14 @@ static int soft_offline_in_use_page(struct page *page) >> * preferred, split it to non-zero new_order like it is done in >> * memory_failure(). >> */ >> - if (new_order || try_to_split_thp_page(page, /* new_order= */ 0, >> - /* release= */ true)) { >> + if (!min_order_for_split(folio)) >> + ret = split_huge_page_to_order(page, 0); >> + else >> + ret = -EBUSY; >> + unlock_page(page); >> + >> + if (ret) { >> + put_page(page); >> pr_info("%#lx: thp split failed\n", pfn); >> return -EBUSY; > > Maybe return ret here? Seems a bit pointless to set ret, gate on it then not > return it (even if result is the same) I didn't check whether a caller actually relies on -EBUSY. So I decided to leave the behavior unchanged. -- Cheers, David