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]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5F39C3ABC0 for ; Thu, 8 May 2025 09:24:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A12AB6B0082; Thu, 8 May 2025 05:24:41 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 9C0746B0088; Thu, 8 May 2025 05:24:41 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 83AF56B0089; Thu, 8 May 2025 05:24:41 -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 672056B0082 for ; Thu, 8 May 2025 05:24:41 -0400 (EDT) Received: from smtpin29.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id BFC841D01E0 for ; Thu, 8 May 2025 09:24:42 +0000 (UTC) X-FDA: 83419205604.29.0D0147F Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by imf14.hostedemail.com (Postfix) with ESMTP id 3F27110000B for ; Thu, 8 May 2025 09:24:40 +0000 (UTC) Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=EBICmJJq; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf14.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1746696280; a=rsa-sha256; cv=none; b=atklTVeArs2TOUqJyaXDOdtgp7d+y6lq3qBh+/2br0BYraCiseZVvptgmYPMdMQxoPwxz5 0pnoOLgcCHJ5EEvv2+KU3P5d74oACP0fAuOkTc58ZHD7d85cOHGkFJv4AfzOFPraItAMYO E6nDNcdgw46VfqFecMkfQ4P+IKXuDNM= ARC-Authentication-Results: i=1; imf14.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=EBICmJJq; dmarc=pass (policy=quarantine) header.from=redhat.com; spf=pass (imf14.hostedemail.com: domain of david@redhat.com designates 170.10.133.124 as permitted sender) smtp.mailfrom=david@redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1746696280; 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=/dlxqAxUZaAt7g7clMdPr7lyvtO4KusfnEelUIQBrfU=; b=mIkvi2UoBxZJF78cQS+Xx/nUx07bYMUtLPgQIVNyKm8hj/UuZ318/Egy4tjBLQ4XDJSTY8 EqnWAFt4qWXkNjGcI/sI/QMBRVPBRwNLtWE8Yluuq7oarfEQ8tvvT8MOI3uzv7zpVPC848 NYmAruCzrC0ZoTye6zcapVu9tByxR54= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1746696279; h=from:from: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:autocrypt:autocrypt; bh=/dlxqAxUZaAt7g7clMdPr7lyvtO4KusfnEelUIQBrfU=; b=EBICmJJq11RxKnbsTJh5iUTGmk46MvdURVWfbSqVh+vrpoT0MBlHqckm70bKJX4TRmzkBK tQIQIQ+VTJubqWvmz955LleUOTg1P98euAWldrzIGUqCh8vD1/ItA++Fe4PXq+8UhQo2qo 1/5Xi1xY8cuUk7ESRzt1kPDS1GSSGmA= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-650-rEnaJJ1GNveJrMDesbR5Tg-1; Thu, 08 May 2025 05:24:38 -0400 X-MC-Unique: rEnaJJ1GNveJrMDesbR5Tg-1 X-Mimecast-MFC-AGG-ID: rEnaJJ1GNveJrMDesbR5Tg_1746696277 Received: by mail-wm1-f71.google.com with SMTP id 5b1f17b1804b1-43d209dc2d3so3402505e9.3 for ; Thu, 08 May 2025 02:24:38 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1746696277; x=1747301077; h=content-transfer-encoding:in-reply-to:organization:autocrypt :content-language:from:references:cc:to:subject:user-agent :mime-version:date:message-id:x-gm-message-state:from:to:cc:subject :date:message-id:reply-to; bh=/dlxqAxUZaAt7g7clMdPr7lyvtO4KusfnEelUIQBrfU=; b=RadrRAw5wdPkzcuPi9WH2ryRSO31RPim/ag+ljjdpvFjNLONRLG19DeLihETpkwmxa 7zlTnWDav/wdzHfGkJdrLQsoC6xFFmkJYBqod7B+HQuz4FXiMeM87+nmiABkd/XiOlX0 lg1946drJ5rOs4++YCM2IAcKHwZXKLoaAiKmRAGG9vHeYRgmIwslZhwvO4olxfGXwsPR n295W9WMKdcqcjrWKEazmru0MZMvV2bYDquL1KGKO4NohgdeVMYkZzPg7ABYoIiLuGBq cpR4l+tJ3cAEgWGN7yEShx7IwChQ+UEmE+VkhjeCB9cz5nah2KGD3mok1n6elwckAJz9 0wrg== X-Forwarded-Encrypted: i=1; AJvYcCUjpd57PEjXLEv0DdhG6aK0RtGvx5FQ2iEttiVlIs4uN1nNHpZOGfrFx7Smy41rYAZCSDzguS7nhg==@kvack.org X-Gm-Message-State: AOJu0Yzol6zFNAeyuwnzXlHsRGpO3Ob6P8DfANRFDvg+atYd0zaySQar Zn2aTvxNCo6qHvmtgXTfeO50TjIguaNgHJHYyMQ1ju/MvcT//IHTMpI9mIU+63DV11B2qEfNVy+ 7eiF0icrGr/5N9/IclSL81RtwYhAlOkhNxi0C+MBD4P6w641Q X-Gm-Gg: ASbGncvZNDKoSelP8+Fnt9rzAfsNIFmbh3rq8eqLQbslOaACEgbNMqfjkVkYlDiso/X nlZaDqWiuf2AgOkDpt7D41QJcJUWkE1BwGCXxcH2RtIyBupk0+a3hvP+3kUMq63jgZyCDb4KvcR +EHgr0Y6iADqO+dZgg215GkDe4Mk8bxigsTeSOqmcesJ597MtYoX3YLFsIsWha5EONopqKddFed Ybzib7gWMyn63bMXJ2Y/un3xpYP++L6MoVASdVoIExxfrKZ8fy4oQ2cV15h+dkFKUlggcBtYsdb 1Fr//L0LfFw7+IUeC8BFZD3Z0J0Q5J2Quq9t+Pk1K+wYEsDEoEnWnOI4uF51srM1A2XuZwO1n// O3CVzIyl8cAg0zeG1zemme83tUafCx0WaJ/7urdQ= X-Received: by 2002:a05:600c:8186:b0:442:ccf9:e6f2 with SMTP id 5b1f17b1804b1-442ccf9f153mr46315275e9.16.1746696277297; Thu, 08 May 2025 02:24:37 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFmkno/mhxrd9N4OZqFeNahYtTVQaRZNkJxl/ggkkKu2E6OOqDo4H2zrQWAIVF+FLCz9vkkNg== X-Received: by 2002:a05:600c:8186:b0:442:ccf9:e6f2 with SMTP id 5b1f17b1804b1-442ccf9f153mr46315005e9.16.1746696276924; Thu, 08 May 2025 02:24:36 -0700 (PDT) Received: from ?IPV6:2003:d8:2f3e:5900:27aa:5f4a:b65c:3d3c? (p200300d82f3e590027aa5f4ab65c3d3c.dip0.t-ipconnect.de. [2003:d8:2f3e:5900:27aa:5f4a:b65c:3d3c]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-442cd34bef4sm31036855e9.24.2025.05.08.02.24.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 08 May 2025 02:24:36 -0700 (PDT) Message-ID: <0e00e429-01d8-4504-8238-565e1bca5ad3@redhat.com> Date: Thu, 8 May 2025 11:24:35 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH RFC] mm: userfaultfd: correct dirty flags set for both present and swap pte To: Barry Song <21cnbao@gmail.com>, akpm@linux-foundation.org, linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, Barry Song , Peter Xu , Suren Baghdasaryan , Lokesh Gidra References: <20250508090735.39756-1-21cnbao@gmail.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: <20250508090735.39756-1-21cnbao@gmail.com> X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: l5rII3TZ6l7PsqQUuO3X5ddWMwU51WnQtiXgAKF9Bfs_1746696277 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: 3F27110000B X-Stat-Signature: xm3hh7jaz67r4893oo51bq9me9e9eqmc X-Rspam-User: X-HE-Tag: 1746696280-694279 X-HE-Meta: U2FsdGVkX1/Mx56PF8UxALsYjISCjAbhMYMqoSOiVCjfBOkx913+68hNBzsca7NNm6HPztb+juWJ+B85fSLiOeotR5AwKFtaIqBDV6M6hFRFL67z8zZz1xMwGavzQiLIu69uNguvqO8kwcCZCifuJBeLgcF/JZRkSWK1znSPoWqIpa2MMBR2+dN4Eri04tlvyI1qqU1lrEbcnz3D8AH2lgVKHLHgpf5JofWB65PQUAxBAql6KenTGFZzSraokrBFC9bBfdmAa8QSBuqbhze87ENOUHTdI4vR9WfEymijG/nMGTuJEFXcAYFEWq7F26BvvgVO+SgqmsJEVoIorR6ebCMUT6zwChoZoY/ZziqtBy32CRKPYOu3foqSWgTWjJhHun7A9vw36TLeTSLtBD7z+21eTtL9ysuXBqMyiktke2lOqHFTGb1FsydfaSh3jvmO6cSV94uwNZ1GZIRItr4LInjboq56q+So7XF+CeB63o+8lai65L+RfgB9fYSY4ShTBhQ/PnmQ5wH04tvW82aYa0hNcMavGYn8tGc4BHNhGdOq99aYzPQtJIM2sY/CIRVeGEgbnH/jIyvXALcRs9TVj531Ek3WNXQekXsXGKDPsKnIwR8LOdcIBkZZ8klrutw9LJyqWfuNxVx8k75Qe6BVQ/s7+rYokPl6tLRQTNIJ48TahnLnHP/0EXFCFHsih1z+jSL+tXeU1U3u4ShNcmNqb8lgHIFZHjEvZ3nRCFySNhGo05MVJX2mBnycQTSRXJWh2FFRlq1dQlvfA3fUdLUcQESHFinwwVH8tE1LwLEAI2OFFzKiv5d1xqjUFSBB6F5kzjR6LicMhgC/XQSjqs5gm9GuA0UYcVV8MuKtUcilJ/s91KrlwR8keV5mlZL0V7qF87VMzV4HmUm0wOoTEOGEezOsqSkDe1RAhuoLYiIVggVpxHxiVev0/3IOup9YNe5HEpo6PLCP0/hxl61LCGd BzyvPnhv /Ze+0ctEkjrXPOOD7UPuHMt0mN1/mWKEM2cRyPco/Hd0bxYJuaB/NK4EiygmEIuqKzWsizjprxch3LLy12yr4Wa0Op0PURSI7owJ5d4DVq6lXu5yIci7yy3yGeu+qGAmvvEAPX/O6PD0ggyomMUTjSXbO+sVS0MD12ainpt9tGneDFUfsrMN87NekXoNdmE4fjfJ73TWur6oaL1JTMUtOug8CV8sBr7y0Aj/aKdiZ5Y7CMaAEK1xbedyRJ/mjfjM9yv9uOF6nuZ9zZQfcckpK4zXl/o8jBHKHCfy4K70uenniZ2cIJXlpyfG9SjAg+KlOAiDUPWjyqwSpBbfAGCHQOUgI2N/943hw2puf2H9BhT3/TyBrQPCcO+D1UolsVRiR4KywY8KR6qdVErDNVWrr5fDmnY+YcerF7RIKHNhecRIuFzqS3dwsdsy5g1uf43JtHTyajU2L6SKyzXaOnActy7chd4JyF2nGBaOrPid7GDtFYlGhPGNll9XXI5slrJ50dZWHkq7sRCoF1HjQ4BYFxf5NhlcHNYl1VHCP7SrbfG8EuNwW1tv+yW2P80PZncw3n8cPwQnQ5VzpZjyMO98opoUxqLp8FmB8ZgQ9fXI3wTKW2tg= X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 08.05.25 11:07, Barry Song wrote: > From: Barry Song > > As David pointed out, what truly matters for mremap and userfaultfd > move operations is the soft dirty bit. The current comment and > implementation—which always sets the dirty bit for present PTEs > and fails to set the soft dirty bit for swap PTEs—are incorrect. > This patch updates the behavior to correctly set the soft dirty bit > for both present and swap PTEs in accordance with mremap. > > Reported-by: David Hildenbrand > Closes: https://lore.kernel.org/linux-mm/02f14ee1-923f-47e3-a994-4950afb9afcc@redhat.com/ > Cc: Peter Xu > Cc: Suren Baghdasaryan > Cc: Lokesh Gidra > Signed-off-by: Barry Song > --- > mm/userfaultfd.c | 12 ++++++++++-- > 1 file changed, 10 insertions(+), 2 deletions(-) > > diff --git a/mm/userfaultfd.c b/mm/userfaultfd.c > index e8ce92dc105f..bc473ad21202 100644 > --- a/mm/userfaultfd.c > +++ b/mm/userfaultfd.c > @@ -1064,8 +1064,13 @@ static int move_present_pte(struct mm_struct *mm, > src_folio->index = linear_page_index(dst_vma, dst_addr); > > orig_dst_pte = folio_mk_pte(src_folio, dst_vma->vm_page_prot); > - /* Follow mremap() behavior and treat the entry dirty after the move */ > - orig_dst_pte = pte_mkwrite(pte_mkdirty(orig_dst_pte), dst_vma); > + /* Set soft dirty bit so userspace can notice the pte was moved */ > +#ifdef CONFIG_MEM_SOFT_DIRTY > + orig_dst_pte = pte_mksoft_dirty(orig_dst_pte); > +#endif > + if (pte_dirty(orig_src_pte)) > + orig_dst_pte = pte_mkdirty(orig_dst_pte); > + orig_dst_pte = pte_mkwrite(orig_dst_pte, dst_vma); > > set_pte_at(mm, dst_addr, dst_pte, orig_dst_pte); > out: > @@ -1100,6 +1105,9 @@ static int move_swap_pte(struct mm_struct *mm, struct vm_area_struct *dst_vma, > } > > orig_src_pte = ptep_get_and_clear(mm, src_addr, src_pte); > +#ifdef CONFIG_MEM_SOFT_DIRTY > + orig_src_pte = pte_swp_mksoft_dirty(orig_src_pte); > +#endif > set_pte_at(mm, dst_addr, dst_pte, orig_src_pte); > double_pt_unlock(dst_ptl, src_ptl); Yeah, I think that should be the right thing to do. -- Cheers, David / dhildenb