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 8CE44C4332F for ; Mon, 7 Nov 2022 17:34:56 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 065666B0073; Mon, 7 Nov 2022 12:34:56 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id F30AE6B0075; Mon, 7 Nov 2022 12:34:55 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DD2048E0001; Mon, 7 Nov 2022 12:34:55 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id CC1356B0073 for ; Mon, 7 Nov 2022 12:34:55 -0500 (EST) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 3BB23AB48B for ; Mon, 7 Nov 2022 17:34:55 +0000 (UTC) X-FDA: 80107346550.07.8DB52CE Received: from mail-oa1-f53.google.com (mail-oa1-f53.google.com [209.85.160.53]) by imf09.hostedemail.com (Postfix) with ESMTP id C5B16140008 for ; Mon, 7 Nov 2022 17:34:54 +0000 (UTC) Received: by mail-oa1-f53.google.com with SMTP id 586e51a60fabf-13bef14ea06so13485181fac.3 for ; Mon, 07 Nov 2022 09:34:54 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:from:to:cc:subject:date:message-id:reply-to; bh=OtwMIMageNgEFgITDbP/X4AlmExFVOD7QsjK39jRkOs=; b=ZrBbGd0NE5W3bFjfpMfVEGchJiOqL5vKGUnJZWHQEDCz71oryF6CDiPscJkkJaNeeg /pKDfIl6hW5yw8tjgrcZSOwrloCrFqYb1/s9Bc1/cV94xFkaKkZwH1bCSgyaTCtOH5Nq 2ijwSehO6aXkrD87GuWevIaaXGPhzXmGc/u0k= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=cc:to:subject:message-id:date:from:in-reply-to:references :mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=OtwMIMageNgEFgITDbP/X4AlmExFVOD7QsjK39jRkOs=; b=eg+sO86exj/riw2NAd15fserjqVBqg84xTg/ZB+l4gJWYM7p7b4hvlRzwOXgv826+e ijnsNPGPLC8D2faoYIX51UdzwPS9WzdJAeO0sHIIvKWnCQVpdEgy3RrBteI8AB1ml0Ze wZ9XIMN83ii8llpxPRwG2aSS7QkDwo2jqfy3HFFoS37GQO5Wlmqr8yOQ3UJKnMO5g9gM AqN9ctfSg6sefYIa1IldO1Wxb8bzovynIRGmz91QP/mpdN34tqHogJsqHFnIjBRuCiL+ kTLCMHnondbddORdoZjZzvQbv70q/7fEiOsU5NUhl8nJja78Q76R04dQWYKkBUczbzlC f5JQ== X-Gm-Message-State: ACrzQf17jZbDhCBNhOX2aqtQ+cpJM7SA/LVIVF2E+lTxh+8M7g739jkn N5U5SuVWynIMqafKt5U8MuIEbwQHhPODtw== X-Google-Smtp-Source: AMsMyM6xUiNQeNsHKjmRE4MDBMkuaK54UvSu2v+7ECUsm8sAfaKYmmZnyy0Yy1Gc85P835NHDckAaQ== X-Received: by 2002:a05:6870:b01c:b0:133:3666:1ecc with SMTP id y28-20020a056870b01c00b0013336661eccmr29718508oae.45.1667842493542; Mon, 07 Nov 2022 09:34:53 -0800 (PST) Received: from mail-ot1-f48.google.com (mail-ot1-f48.google.com. [209.85.210.48]) by smtp.gmail.com with ESMTPSA id q189-20020acac0c6000000b0035a0c543ad6sm2615735oif.21.2022.11.07.09.34.52 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 07 Nov 2022 09:34:53 -0800 (PST) Received: by mail-ot1-f48.google.com with SMTP id a7-20020a056830008700b0066c82848060so6793416oto.4 for ; Mon, 07 Nov 2022 09:34:52 -0800 (PST) X-Received: by 2002:a05:6902:1352:b0:6bb:3f4b:9666 with SMTP id g18-20020a056902135200b006bb3f4b9666mr46634218ybu.101.1667842059236; Mon, 07 Nov 2022 09:27:39 -0800 (PST) MIME-Version: 1.0 References: <20221107161740.144456-1-david@redhat.com> In-Reply-To: <20221107161740.144456-1-david@redhat.com> From: Linus Torvalds Date: Mon, 7 Nov 2022 09:27:23 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH RFC 00/19] mm/gup: remove FOLL_FORCE usage from drivers (reliable R/O long-term pinning) To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-arm-kernel@lists.infradead.org, linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-kselftest@vger.kernel.org, Andrew Morton , Jason Gunthorpe , John Hubbard , Peter Xu , Greg Kroah-Hartman , Andrea Arcangeli , Hugh Dickins , Nadav Amit , Vlastimil Babka , Matthew Wilcox , Mike Kravetz , Muchun Song , Lucas Stach , David Airlie , Oded Gabbay , Arnd Bergmann Content-Type: text/plain; charset="UTF-8" ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1667842494; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=OtwMIMageNgEFgITDbP/X4AlmExFVOD7QsjK39jRkOs=; b=QWkMKSGiAD9QwD/vIpPf0JTZzo/P18O3sSJs5UZ0sMaXo/PvAOj42RDnlXqWu5bVJKILNP UbFuIxGR/nALAnqoz02dXgqIV2bx3Btq9R7eY8lvot6zPd8tghPj2drhV8L8XbzFLa5cn2 2JvSrzxAw8njhUyFaPB8UtbcLPg4QVU= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=google header.b=ZrBbGd0N; spf=pass (imf09.hostedemail.com: domain of torvalds@linuxfoundation.org designates 209.85.160.53 as permitted sender) smtp.mailfrom=torvalds@linuxfoundation.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1667842494; a=rsa-sha256; cv=none; b=x/asszTBl/hSpIJomzT2o/eCtFAKkO/wGVy35ShoWEq42zQgTPK6T4uVfKMF3YclbxxNU7 D96gdN64udZw360bvj+cLzH0qnt/05VahmlWBHylHiwj01Ue4O3FQfuR6eND1kanq7+FTI RakZZxPfPIQvOR9qmtqUYUHH1ZuhjLY= Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=google header.b=ZrBbGd0N; spf=pass (imf09.hostedemail.com: domain of torvalds@linuxfoundation.org designates 209.85.160.53 as permitted sender) smtp.mailfrom=torvalds@linuxfoundation.org; dmarc=none X-Rspam-User: X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: C5B16140008 X-Stat-Signature: hqqbybotmk17o6orzn544s8fxu7so3wm X-HE-Tag: 1667842494-483532 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: On Mon, Nov 7, 2022 at 8:18 AM David Hildenbrand wrote: > > So instead, make R/O long-term pinning work as expected, by breaking COW > in a COW mapping early, such that we can remove any FOLL_FORCE usage from > drivers. Nothing makes me unhappy from a quick scan through these patches. And I'd really love to just have this long saga ended, and FOLL_FORCE finally relegated to purely ptrace accesses. So an enthusiastic Ack from me. Linus