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 9A346EEAA43 for ; Thu, 14 Sep 2023 13:43:53 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E6D136B02B3; Thu, 14 Sep 2023 09:43:52 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E1B006B02B8; Thu, 14 Sep 2023 09:43:52 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D0A376B02B9; Thu, 14 Sep 2023 09:43:52 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id BFCB06B02B3 for ; Thu, 14 Sep 2023 09:43:52 -0400 (EDT) Received: from smtpin20.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay01.hostedemail.com (Postfix) with ESMTP id 887951C9BA7 for ; Thu, 14 Sep 2023 13:43:52 +0000 (UTC) X-FDA: 81235321104.20.0CDA8FD Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf01.hostedemail.com (Postfix) with ESMTP id 46FC740015 for ; Thu, 14 Sep 2023 13:43:50 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="X8hT/Fil"; spf=pass (imf01.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1694699030; 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=7g/3uMhl9MZDE/ThW7epr+QQ++XKktE4v6z5BQlLBX0=; b=CowR5Mktj2EC4ZgUHs41w5HnZMpIVvLC7DGCCVQ0UflBLdglbr1SAYCUH//RYm4g7ye7ba 6G969QG8hsZ0xEewz+uKZWgnnS3yZqvExHrnpJN8aOU7zkj0x93Wy4yOnGXtY+f7mZuD9B BwQ8OToKOkXUkAav/xSum15lGdDtlpM= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b="X8hT/Fil"; spf=pass (imf01.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1694699030; a=rsa-sha256; cv=none; b=Y+ANYmhcdKc9B7tu09/+ZKsWbQYjDlaTqy1dQwtEzAG5Sg/zmVPMTTtq2zt8qHsL8kgcGw Cndu7JPCjg48PcJjhutvdzTfoCC6RTZdcCqmHVkfJ7W/BRQHipjl2E0+iCvb7a3/YCa9IV OwDaV3TyFa5NQGiJCyLDAwDxSODohoQ= DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1694699029; 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; bh=7g/3uMhl9MZDE/ThW7epr+QQ++XKktE4v6z5BQlLBX0=; b=X8hT/Fil2ORfF8hO3tq7Tdw/rBZodyHmhaxmBH9AdsAz/4tW8n8XFWV5xtvRtVsu4rsLPV z/JBYESO/5NWWhm40p0kcqbePft4bTwv5CfkFqvP818ur/r2ugs6cy0nwj0NbSLHl13MbT 8All7QCZapd3mm9AbGDesM+27pzxoOM= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-515-INshARfkN0qwkPbq6om6xg-1; Thu, 14 Sep 2023 09:43:48 -0400 X-MC-Unique: INshARfkN0qwkPbq6om6xg-1 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-31c6c275c83so594178f8f.2 for ; Thu, 14 Sep 2023 06:43:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1694699027; x=1695303827; h=content-transfer-encoding:in-reply-to:organization:from:references :cc:to:content-language:subject:user-agent:mime-version:date :message-id:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=7g/3uMhl9MZDE/ThW7epr+QQ++XKktE4v6z5BQlLBX0=; b=uST3B9JdIjypo3vjWc0FYdM/hsCNoVkfSzGI6nOhqXAkwB1yfuNI1gZ6JGBISsmBSd EUxrsoJ/4Uahp0Vz95e+WRA5xqDWAHeDloSpOpycdppA12lLW6VPIRb4lIhXh4Y9nW73 2JdQsdCYXMfqG7i2qdl2PI3y1f2ZDL+Gd/SEgfeXOkCpFttR+SzX7v9le/PRki4yVZd+ L2UoxAvBJlqe3Cjzm42vhsVCNr9bir7XHzmcJrzXBYvx5vFhKmObkvibermFP2j0mPJm z5+qT3TAia1K0o+iSAmj8k8nGhLrA39byKovV6cP6d6NdedF+63xPwX9oC1csAtdpnnr vpMg== X-Gm-Message-State: AOJu0YzGp07KxOmXs1rfgvIsefoE8ghEDVvSw5GQgNs1ENTQJy7u1ZAa l7+2IMNEzmLBXnYj2h7lu+D6jP8fAlBw3/PW8J+pZS2enAvUs1c2jphhIIf1XkifwlNpjbP6R1j dWfSNXh0o5kg= X-Received: by 2002:a5d:5489:0:b0:317:3a18:df26 with SMTP id h9-20020a5d5489000000b003173a18df26mr4798213wrv.39.1694699026759; Thu, 14 Sep 2023 06:43:46 -0700 (PDT) X-Google-Smtp-Source: AGHT+IGl3gx0f8m6ucbY2oUSgYxRo2mV5lZMn5wTHlPG74xgWBAx8MD0rSNrk9s8t7gMoNBNYNBF3g== X-Received: by 2002:a5d:5489:0:b0:317:3a18:df26 with SMTP id h9-20020a5d5489000000b003173a18df26mr4798199wrv.39.1694699026303; Thu, 14 Sep 2023 06:43:46 -0700 (PDT) Received: from ?IPV6:2a09:80c0:192:0:5dac:bf3d:c41:c3e7? ([2a09:80c0:192:0:5dac:bf3d:c41:c3e7]) by smtp.gmail.com with ESMTPSA id r4-20020adfdc84000000b0031753073abcsm1810179wrj.36.2023.09.14.06.43.45 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 14 Sep 2023 06:43:45 -0700 (PDT) Message-ID: Date: Thu, 14 Sep 2023 15:43:44 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH v1 0/3] udmabuf: Add support for page migration out of movable zone or CMA To: Jason Gunthorpe , "Kasireddy, Vivek" Cc: "dri-devel@lists.freedesktop.org" , "linux-mm@kvack.org" , Daniel Vetter , Mike Kravetz , Hugh Dickins , Peter Xu , Gerd Hoffmann , "Kim, Dongwon" , "Chang, Junxiao" References: <8afa35bb-c3ed-c939-46a4-a9a277b6d4e2@redhat.com> <20e38c1d-24e0-4705-6acb-87921962ccee@redhat.com> From: David Hildenbrand Organization: Red Hat In-Reply-To: X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 46FC740015 X-Rspam-User: X-Stat-Signature: 8mzytu6xumuth3iujf38oguxwiz3jziw X-Rspamd-Server: rspam01 X-HE-Tag: 1694699030-713624 X-HE-Meta: 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 RJO8w/kt vCoBrQUfK32u8TuYb9heO38GAAjiiKXkRt5g7A0GVRvNREepVzxoPFVVWYr6KhEViFdHO8sWMfVMgIuX2bb9PZuoU91MU82TeYtD/uQGUpS9v3jnwqrrRCAp6YMKlGKoRTcufGP9oDh6QykDwfYokCG3Qwz+62wq9g4V5Ngz1JK3Dj+OVN5vt2c5S1t02II8OUN7F8k7Wovnsk81FMbxttjtmToyQAtJ2SoHZEkPSBVByRi7j1FFNc4A/DoPrBxHvFlu5VOTyUMdH7dj3+w60ma//NrpoQNBQvu0pVX2zTQXslHO66oELU+uPFXENEdgkAnMHIM2SOKVCUcyuJQfaqdbUeRzlMh3+L1LeFOR5UEBrJ8jgdvUdyocaBi6nxQtmltmpJ+UbkxsxRcOvnmqgEDKQSfEtYLV1P4iiFN/mzmpJeeE= 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: >> I think it makes sense to have a generic (non-GUP) version of >> check_and_migrate_movable_pages() available in migration.h that >> drivers can use to ensure that they don't break memory hotunplug >> accidentally. > > Definately not. > > Either use the VMA and pin_user_pages(), or implement > pin_user_pages_fd() in core code. > > Do not open code something wonky in drivers. Agreed. pin_user_pages_fd() might become relevant in the context of vfio/mdev + KVM gmem -- don't mmap guest memory but instead provide it via a special memfd to the kernel. So there might be value in having such a core infrastructure. -- Cheers, David / dhildenb