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[209.85.167.50]) by smtp.gmail.com with ESMTPSA id v22-20020a05651203b600b00492c663bba2sm1655497lfp.124.2022.11.28.01.04.51 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 28 Nov 2022 01:04:51 -0800 (PST) Received: by mail-lf1-f50.google.com with SMTP id d6so16302700lfs.10 for ; Mon, 28 Nov 2022 01:04:51 -0800 (PST) X-Received: by 2002:aa7:db98:0:b0:46a:d57:d9d0 with SMTP id u24-20020aa7db98000000b0046a0d57d9d0mr25216647edt.113.1669625884043; Mon, 28 Nov 2022 00:58:04 -0800 (PST) MIME-Version: 1.0 References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-17-david@redhat.com> <81fb0fa3-2e06-b765-56ac-a7d981194e59@redhat.com> <08b65ac6-6786-1080-18f8-d2be109c85fc@xs4all.nl> <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> In-Reply-To: <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> From: Tomasz Figa Date: Mon, 28 Nov 2022 17:57:51 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH mm-unstable v1 16/20] mm/frame-vector: remove FOLL_FORCE usage To: David Hildenbrand Cc: Hans Verkuil , linux-kernel@vger.kernel.org, Andrew Morton , x86@kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-perf-users@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kselftest@vger.kernel.org, Linus Torvalds , Jason Gunthorpe , John Hubbard , Peter Xu , Greg Kroah-Hartman , Andrea Arcangeli , Hugh Dickins , Nadav Amit , Vlastimil Babka , Matthew Wilcox , Mike Kravetz , Muchun Song , Shuah Khan , Lucas Stach , David Airlie , Oded Gabbay , Arnd Bergmann , Christoph Hellwig , Alex Williamson , Marek Szyprowski , Mauro Carvalho Chehab Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Mon, Nov 28, 2022 at 5:19 PM David Hildenbrand wrote: > > On 28.11.22 09:17, Hans Verkuil wrote: > > Hi David, > > > > On 27/11/2022 11:35, David Hildenbrand wrote: > >> On 16.11.22 11:26, David Hildenbrand wrote: > >>> FOLL_FORCE is really only for ptrace access. According to commit > >>> 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are always > >>> writable"), get_vaddr_frames() currently pins all pages writable as a > >>> workaround for issues with read-only buffers. > >>> > >>> FOLL_FORCE, however, seems to be a legacy leftover as it predates > >>> commit 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are > >>> always writable"). Let's just remove it. > >>> > >>> Once the read-only buffer issue has been resolved, FOLL_WRITE could > >>> again be set depending on the DMA direction. > >>> > >>> Cc: Hans Verkuil > >>> Cc: Marek Szyprowski > >>> Cc: Tomasz Figa > >>> Cc: Marek Szyprowski > >>> Cc: Mauro Carvalho Chehab > >>> Signed-off-by: David Hildenbrand > >>> --- > >>> drivers/media/common/videobuf2/frame_vector.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/media/common/videobuf2/frame_vector.c b/drivers/media/common/videobuf2/frame_vector.c > >>> index 542dde9d2609..062e98148c53 100644 > >>> --- a/drivers/media/common/videobuf2/frame_vector.c > >>> +++ b/drivers/media/common/videobuf2/frame_vector.c > >>> @@ -50,7 +50,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, > >>> start = untagged_addr(start); > >>> ret = pin_user_pages_fast(start, nr_frames, > >>> - FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM, > >>> + FOLL_WRITE | FOLL_LONGTERM, > >>> (struct page **)(vec->ptrs)); > >>> if (ret > 0) { > >>> vec->got_ref = true; > >> > >> > >> Hi Andrew, > >> > >> see the discussion at [1] regarding a conflict and how to proceed with > >> upstreaming. The conflict would be easy to resolve, however, also > >> the patch description doesn't make sense anymore with [1]. > > > > Might it be easier and less confusing if you post a v2 of this series > > with my patch first? That way it is clear that 1) my patch has to come > > first, and 2) that it is part of a single series and should be merged > > by the mm subsystem. > > > > Less chances of things going wrong that way. > > > > Just mention in the v2 cover letter that the first patch was added to > > make it easy to backport that fix without being hampered by merge > > conflicts if it was added after your frame_vector.c patch. > > Yes, that's the way I would naturally do, it, however, Andrew prefers > delta updates for minor changes. > > @Andrew, whatever you prefer! > > Thanks! > However you folks proceed with taking this patch, feel free to add my Acked-by. Thanks! Best regards, Tomasz > -- > Thanks, > > David / dhildenb > 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 gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C4349C46467 for ; Mon, 28 Nov 2022 08:58:13 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 708F010E2B9; Mon, 28 Nov 2022 08:58:11 +0000 (UTC) Received: from mail-ej1-x62a.google.com (mail-ej1-x62a.google.com [IPv6:2a00:1450:4864:20::62a]) by gabe.freedesktop.org (Postfix) with ESMTPS id D758610E200 for ; Mon, 28 Nov 2022 08:58:07 +0000 (UTC) Received: by mail-ej1-x62a.google.com with SMTP id td2so9915605ejc.5 for ; Mon, 28 Nov 2022 00:58:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.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=iRo5DYRndKCx9sGSXzsZxPr88K/zqtuLTLl1O32mcFE=; b=XOKEpyQaMH8DtU4ghoeum5LLPSyZKKSeL9ukREYJEhE5Pet4ng53VcgxrNVIVOiN3z qM9BvX69vBwubqV7gI66eEPgV5zFoyHzRXj6Y/c3o1k6BVytkDV23dS8hW9lN3urO8Q7 YycsWj1XAMOHph6L7v2J+A4VSfKO7i7WBHunk= 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=iRo5DYRndKCx9sGSXzsZxPr88K/zqtuLTLl1O32mcFE=; b=GVzyXEhhs3GGLMWL4RvGCOGS6slEu43XhG1OihZKmQDroJMWEfZlipTRvDfCdJ2fbJ qb5QP98YrDpDvI79gc6bo6DjShNJA4a1CZjyschzbXXLrgAFPBBV74owqtNFCROQlztV t9VkrhHSEcJeu+nGCuqV6y46YwVtN/A2n3cWVkVOvKQxegAlT3ybmAj91y5Pm4hjTYfM fW8JarRU1pnQ3TnXFOxEuYRIt/AaeZIu5/5sFbxKqiGALaqz5jpASosl3hoFdJprNrk6 zFUc3waZVoOp6WVJC7qf2qGLqtbDCzCAuQ5GjQPKqYEu2GCaM0JiEs02dWalkNUhu8Qq 6gPQ== X-Gm-Message-State: ANoB5plYgwpTlU/SGRC1SvsAJs/u9NGDezBGS/lzb4mmoF8xGR0IhRy/ ApLHYDzsWtUfhTuOR5gk5naF3P/QD5ADDw== X-Google-Smtp-Source: AA0mqf5Dj4be4H++ertjRnYxb8WQIuAbKX0kqVx+racdCBFQkMqbkDfpQQxzKX550cOQqm8FnY1MRg== X-Received: by 2002:a17:907:2904:b0:78d:b598:bb6a with SMTP id eq4-20020a170907290400b0078db598bb6amr28998306ejc.258.1669625886261; Mon, 28 Nov 2022 00:58:06 -0800 (PST) Received: from mail-ed1-f42.google.com (mail-ed1-f42.google.com. [209.85.208.42]) by smtp.gmail.com with ESMTPSA id o26-20020a170906769a00b007b93544ad9dsm4678251ejm.109.2022.11.28.00.58.04 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 28 Nov 2022 00:58:05 -0800 (PST) Received: by mail-ed1-f42.google.com with SMTP id d20so3710229edn.0 for ; Mon, 28 Nov 2022 00:58:04 -0800 (PST) X-Received: by 2002:aa7:db98:0:b0:46a:d57:d9d0 with SMTP id u24-20020aa7db98000000b0046a0d57d9d0mr25216647edt.113.1669625884043; Mon, 28 Nov 2022 00:58:04 -0800 (PST) MIME-Version: 1.0 References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-17-david@redhat.com> <81fb0fa3-2e06-b765-56ac-a7d981194e59@redhat.com> <08b65ac6-6786-1080-18f8-d2be109c85fc@xs4all.nl> <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> In-Reply-To: <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> From: Tomasz Figa Date: Mon, 28 Nov 2022 17:57:51 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH mm-unstable v1 16/20] mm/frame-vector: remove FOLL_FORCE usage To: David Hildenbrand Content-Type: text/plain; charset="UTF-8" X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-ia64@vger.kernel.org, Greg Kroah-Hartman , dri-devel@lists.freedesktop.org, linux-mips@vger.kernel.org, Hans Verkuil , linux-mm@kvack.org, Nadav Amit , linux-kselftest@vger.kernel.org, sparclinux@vger.kernel.org, Shuah Khan , Marek Szyprowski , Andrea Arcangeli , linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, x86@kernel.org, Hugh Dickins , Matthew Wilcox , Christoph Hellwig , Jason Gunthorpe , Vlastimil Babka , linux-media@vger.kernel.org, Arnd Bergmann , John Hubbard , linux-um@lists.infradead.org, etnaviv@lists.freedesktop.org, Alex Williamson , Peter Xu , Muchun Song , Mauro Carvalho Chehab , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, Oded Gabbay , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-security-module@vger.kernel.org, linux-alpha@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , Linus Torvalds , Mike Kravetz Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Mon, Nov 28, 2022 at 5:19 PM David Hildenbrand wrote: > > On 28.11.22 09:17, Hans Verkuil wrote: > > Hi David, > > > > On 27/11/2022 11:35, David Hildenbrand wrote: > >> On 16.11.22 11:26, David Hildenbrand wrote: > >>> FOLL_FORCE is really only for ptrace access. According to commit > >>> 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are always > >>> writable"), get_vaddr_frames() currently pins all pages writable as a > >>> workaround for issues with read-only buffers. > >>> > >>> FOLL_FORCE, however, seems to be a legacy leftover as it predates > >>> commit 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are > >>> always writable"). Let's just remove it. > >>> > >>> Once the read-only buffer issue has been resolved, FOLL_WRITE could > >>> again be set depending on the DMA direction. > >>> > >>> Cc: Hans Verkuil > >>> Cc: Marek Szyprowski > >>> Cc: Tomasz Figa > >>> Cc: Marek Szyprowski > >>> Cc: Mauro Carvalho Chehab > >>> Signed-off-by: David Hildenbrand > >>> --- > >>> drivers/media/common/videobuf2/frame_vector.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/media/common/videobuf2/frame_vector.c b/drivers/media/common/videobuf2/frame_vector.c > >>> index 542dde9d2609..062e98148c53 100644 > >>> --- a/drivers/media/common/videobuf2/frame_vector.c > >>> +++ b/drivers/media/common/videobuf2/frame_vector.c > >>> @@ -50,7 +50,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, > >>> start = untagged_addr(start); > >>> ret = pin_user_pages_fast(start, nr_frames, > >>> - FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM, > >>> + FOLL_WRITE | FOLL_LONGTERM, > >>> (struct page **)(vec->ptrs)); > >>> if (ret > 0) { > >>> vec->got_ref = true; > >> > >> > >> Hi Andrew, > >> > >> see the discussion at [1] regarding a conflict and how to proceed with > >> upstreaming. The conflict would be easy to resolve, however, also > >> the patch description doesn't make sense anymore with [1]. > > > > Might it be easier and less confusing if you post a v2 of this series > > with my patch first? That way it is clear that 1) my patch has to come > > first, and 2) that it is part of a single series and should be merged > > by the mm subsystem. > > > > Less chances of things going wrong that way. > > > > Just mention in the v2 cover letter that the first patch was added to > > make it easy to backport that fix without being hampered by merge > > conflicts if it was added after your frame_vector.c patch. > > Yes, that's the way I would naturally do, it, however, Andrew prefers > delta updates for minor changes. > > @Andrew, whatever you prefer! > > Thanks! > However you folks proceed with taking this patch, feel free to add my Acked-by. Thanks! Best regards, Tomasz > -- > Thanks, > > David / dhildenb > 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 lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8E3FBC4332F for ; Mon, 28 Nov 2022 08:59:12 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4NLKCL6kmLz3ccw for ; Mon, 28 Nov 2022 19:59:10 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.a=rsa-sha256 header.s=google header.b=XOKEpyQa; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=chromium.org (client-ip=2a00:1450:4864:20::530; helo=mail-ed1-x530.google.com; envelope-from=tfiga@chromium.org; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=chromium.org header.i=@chromium.org header.a=rsa-sha256 header.s=google header.b=XOKEpyQa; dkim-atps=neutral Received: from mail-ed1-x530.google.com (mail-ed1-x530.google.com [IPv6:2a00:1450:4864:20::530]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4NLKBK4qxxz2xmg for ; Mon, 28 Nov 2022 19:58:15 +1100 (AEDT) Received: by mail-ed1-x530.google.com with SMTP id m19so13239430edj.8 for ; Mon, 28 Nov 2022 00:58:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.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=iRo5DYRndKCx9sGSXzsZxPr88K/zqtuLTLl1O32mcFE=; b=XOKEpyQaMH8DtU4ghoeum5LLPSyZKKSeL9ukREYJEhE5Pet4ng53VcgxrNVIVOiN3z qM9BvX69vBwubqV7gI66eEPgV5zFoyHzRXj6Y/c3o1k6BVytkDV23dS8hW9lN3urO8Q7 YycsWj1XAMOHph6L7v2J+A4VSfKO7i7WBHunk= 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=iRo5DYRndKCx9sGSXzsZxPr88K/zqtuLTLl1O32mcFE=; b=Ht5Yd1zo1U0LdJKwOyHlzh7neBY45FZMelWL+70mAFaVG7UbbL/HymD8HzW/rIKnxm dzYRF/FFAOYzeHXV5P3MIH6kuolW2g99/tfUGxi1Tac9M0tXob/2uv8FwOX81zUD/uen R5mo7kpGODod2wsV+lFBhpWa0RLP3m8S6seuT3tAMfVC973bJ/MFyBnsKpqvrRsTKsFR tMIR/ZtvRSD4lnHalQG5E+TPZsBgLR+SmTfjIuu+dL4dqFrvNTFz5jnvgd3mDBI9o7Cb hK7pkYEBhRt7XF1jpqTRfkMx8HctOF6H+xYIU1YZrSYK6+j1ok4eOiyEhbZxXQdXrwgu a++w== X-Gm-Message-State: ANoB5pnqk+heYXdiGxw2Dd8DUuqESoUUlqm2UNah9axV37PxC5juePKv +vXD+pFZ3BgNEvaVgLR4p0nv4XFRxCQJ9A== X-Google-Smtp-Source: AA0mqf59uQUuJt/b4++W3EushRfjQtuQsrsnrBYG8HHj0336NrxS2zzmTxK1I5QsouQrw0VYhiWs/g== X-Received: by 2002:a05:6402:2948:b0:463:bc31:2604 with SMTP id ed8-20020a056402294800b00463bc312604mr45729764edb.32.1669625886008; Mon, 28 Nov 2022 00:58:06 -0800 (PST) Received: from mail-ed1-f48.google.com (mail-ed1-f48.google.com. [209.85.208.48]) by smtp.gmail.com with ESMTPSA id cd26-20020a170906b35a00b007a4e02e32ffsm4667575ejb.60.2022.11.28.00.58.04 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 28 Nov 2022 00:58:05 -0800 (PST) Received: by mail-ed1-f48.google.com with SMTP id z20so14445910edc.13 for ; Mon, 28 Nov 2022 00:58:04 -0800 (PST) X-Received: by 2002:aa7:db98:0:b0:46a:d57:d9d0 with SMTP id u24-20020aa7db98000000b0046a0d57d9d0mr25216647edt.113.1669625884043; Mon, 28 Nov 2022 00:58:04 -0800 (PST) MIME-Version: 1.0 References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-17-david@redhat.com> <81fb0fa3-2e06-b765-56ac-a7d981194e59@redhat.com> <08b65ac6-6786-1080-18f8-d2be109c85fc@xs4all.nl> <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> In-Reply-To: <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> From: Tomasz Figa Date: Mon, 28 Nov 2022 17:57:51 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH mm-unstable v1 16/20] mm/frame-vector: remove FOLL_FORCE usage To: David Hildenbrand Content-Type: text/plain; charset="UTF-8" X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-ia64@vger.kernel.org, Greg Kroah-Hartman , dri-devel@lists.freedesktop.org, linux-mips@vger.kernel.org, Hans Verkuil , linux-mm@kvack.org, Nadav Amit , linux-kselftest@vger.kernel.org, sparclinux@vger.kernel.org, Shuah Khan , Marek Szyprowski , Andrea Arcangeli , linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, David Airlie , x86@kernel.org, Hugh Dickins , Matthew Wilcox , Christoph Hellwig , Jason Gunthorpe , Vlastimil Babka , linux-media@vger.kernel.org, Arnd Bergmann , John Hubbard , linux-um@lists.infradead.org, etnaviv@lists.freedesktop.org, Alex Williamson , Peter Xu , Muchun Song , Mauro Carvalho Chehab , linux-arm-kernel@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, Oded Gabbay , linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, linux-security-module@vger.kernel.org, linux-alpha@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , Lucas Stach , Linus Torvalds , Mike Kravetz Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Mon, Nov 28, 2022 at 5:19 PM David Hildenbrand wrote: > > On 28.11.22 09:17, Hans Verkuil wrote: > > Hi David, > > > > On 27/11/2022 11:35, David Hildenbrand wrote: > >> On 16.11.22 11:26, David Hildenbrand wrote: > >>> FOLL_FORCE is really only for ptrace access. According to commit > >>> 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are always > >>> writable"), get_vaddr_frames() currently pins all pages writable as a > >>> workaround for issues with read-only buffers. > >>> > >>> FOLL_FORCE, however, seems to be a legacy leftover as it predates > >>> commit 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are > >>> always writable"). Let's just remove it. > >>> > >>> Once the read-only buffer issue has been resolved, FOLL_WRITE could > >>> again be set depending on the DMA direction. > >>> > >>> Cc: Hans Verkuil > >>> Cc: Marek Szyprowski > >>> Cc: Tomasz Figa > >>> Cc: Marek Szyprowski > >>> Cc: Mauro Carvalho Chehab > >>> Signed-off-by: David Hildenbrand > >>> --- > >>> drivers/media/common/videobuf2/frame_vector.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/media/common/videobuf2/frame_vector.c b/drivers/media/common/videobuf2/frame_vector.c > >>> index 542dde9d2609..062e98148c53 100644 > >>> --- a/drivers/media/common/videobuf2/frame_vector.c > >>> +++ b/drivers/media/common/videobuf2/frame_vector.c > >>> @@ -50,7 +50,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, > >>> start = untagged_addr(start); > >>> ret = pin_user_pages_fast(start, nr_frames, > >>> - FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM, > >>> + FOLL_WRITE | FOLL_LONGTERM, > >>> (struct page **)(vec->ptrs)); > >>> if (ret > 0) { > >>> vec->got_ref = true; > >> > >> > >> Hi Andrew, > >> > >> see the discussion at [1] regarding a conflict and how to proceed with > >> upstreaming. The conflict would be easy to resolve, however, also > >> the patch description doesn't make sense anymore with [1]. > > > > Might it be easier and less confusing if you post a v2 of this series > > with my patch first? That way it is clear that 1) my patch has to come > > first, and 2) that it is part of a single series and should be merged > > by the mm subsystem. > > > > Less chances of things going wrong that way. > > > > Just mention in the v2 cover letter that the first patch was added to > > make it easy to backport that fix without being hampered by merge > > conflicts if it was added after your frame_vector.c patch. > > Yes, that's the way I would naturally do, it, however, Andrew prefers > delta updates for minor changes. > > @Andrew, whatever you prefer! > > Thanks! > However you folks proceed with taking this patch, feel free to add my Acked-by. Thanks! Best regards, Tomasz > -- > Thanks, > > David / dhildenb > 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 648CEC4332F for ; Mon, 28 Nov 2022 09:06:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=XwuxKxPXHi0oFPf/4VtNtOfqk2bbWNSEmowDiDTGHCY=; b=BDwhh4RF7H41D4 FZZZX+BF9dLdnwZto+ycpnElDaIVUHXyjm8ShK6C8IYQmWS7P4e3FWCMEjf09yFP6zDVr6wxj8o0f qHogoekjeUJrBwOx+8Mjk9pL5h9krdrMqwjkEADghprCbyK8XNNfbtJjSu3sQ74lrDJCfjBkUGsOm k4nQzrSBSfQuspkORcaMZq0YLR2K4pbLHn+PTzacXPW74uLFDrh2tv55OZaTzjBkLCbUk3QBNMRm7 8DCAa0wGRnqaqUw/qVDZhVKzoyRxRl4px1DNiPce9Xf7bC+Z948BwYssFGr2RgyeVwORlxtpKC1gX 2FGPeDXW8LZjfhXtQWYw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1oza53-000URz-Ih; Mon, 28 Nov 2022 09:05:37 +0000 Received: from mail-ej1-x62b.google.com ([2a00:1450:4864:20::62b]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1oza50-000UPt-0e for linux-arm-kernel@lists.infradead.org; Mon, 28 Nov 2022 09:05:35 +0000 Received: by mail-ej1-x62b.google.com with SMTP id td2so9960844ejc.5 for ; Mon, 28 Nov 2022 01:05:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.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=iRo5DYRndKCx9sGSXzsZxPr88K/zqtuLTLl1O32mcFE=; b=XOKEpyQaMH8DtU4ghoeum5LLPSyZKKSeL9ukREYJEhE5Pet4ng53VcgxrNVIVOiN3z qM9BvX69vBwubqV7gI66eEPgV5zFoyHzRXj6Y/c3o1k6BVytkDV23dS8hW9lN3urO8Q7 YycsWj1XAMOHph6L7v2J+A4VSfKO7i7WBHunk= 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=iRo5DYRndKCx9sGSXzsZxPr88K/zqtuLTLl1O32mcFE=; b=xkgQsiKNyGH6bhZ8LJEsDLcdYAHzq5CnAeziluiVeGfR7Hi4pyxCrLq2WORV4QtB2/ bCOIAH1RLt0p3+U0AnQjiuxMXIgN+wkLYUl22GrL0ux8CytpSTeOcPXZNw76DPx3o3N/ mLDrtZbzqtJSAvzm8IdZiUNNC38ATmwB03XbYXDiMarGv2Bhu8g31lQEV3/yDvaZKEp2 MBJ7IbozvFQjNtGy1cCoabIhcEcdFJi47I8ofnxB/2w4cIjoevoN77BsYQ72hIvX51X+ U8BA26Gq7lgSxs/C2ImRg4+jeK4r3bCjG3t10znVNpIoYFfuFWG2woh/gHsAzxAXJDTi hzyg== X-Gm-Message-State: ANoB5plqZdMZps2swqid3OivtUdCRX8d/WPSnW1PI2KjjJOQ3crS2fzL uRr7r4yXz41mAUqYkfTgjJlNU+GEo9nXOOwr X-Google-Smtp-Source: AA0mqf4C/BVZCQMmV1ZOx/VSWt/0tRF6liMNzzYSwDOW42XLhgpRrzSmT9GVcdqmFVsY1XcVnZnKKg== X-Received: by 2002:a17:907:8b13:b0:781:541:6599 with SMTP id sz19-20020a1709078b1300b0078105416599mr30083319ejc.45.1669626331649; Mon, 28 Nov 2022 01:05:31 -0800 (PST) Received: from mail-ed1-f47.google.com (mail-ed1-f47.google.com. [209.85.208.47]) by smtp.gmail.com with ESMTPSA id p27-20020a17090628db00b007ae4717bef1sm4783147ejd.15.2022.11.28.01.05.31 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 28 Nov 2022 01:05:31 -0800 (PST) Received: by mail-ed1-f47.google.com with SMTP id r26so12399952edc.10 for ; Mon, 28 Nov 2022 01:05:31 -0800 (PST) X-Received: by 2002:aa7:db98:0:b0:46a:d57:d9d0 with SMTP id u24-20020aa7db98000000b0046a0d57d9d0mr25216647edt.113.1669625884043; Mon, 28 Nov 2022 00:58:04 -0800 (PST) MIME-Version: 1.0 References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-17-david@redhat.com> <81fb0fa3-2e06-b765-56ac-a7d981194e59@redhat.com> <08b65ac6-6786-1080-18f8-d2be109c85fc@xs4all.nl> <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> In-Reply-To: <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> From: Tomasz Figa Date: Mon, 28 Nov 2022 17:57:51 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH mm-unstable v1 16/20] mm/frame-vector: remove FOLL_FORCE usage To: David Hildenbrand Cc: Hans Verkuil , linux-kernel@vger.kernel.org, Andrew Morton , x86@kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-perf-users@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kselftest@vger.kernel.org, Linus Torvalds , Jason Gunthorpe , John Hubbard , Peter Xu , Greg Kroah-Hartman , Andrea Arcangeli , Hugh Dickins , Nadav Amit , Vlastimil Babka , Matthew Wilcox , Mike Kravetz , Muchun Song , Shuah Khan , Lucas Stach , David Airlie , Oded Gabbay , Arnd Bergmann , Christoph Hellwig , Alex Williamson , Marek Szyprowski , Mauro Carvalho Chehab X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221128_010534_077974_70E0890F X-CRM114-Status: GOOD ( 34.04 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Nov 28, 2022 at 5:19 PM David Hildenbrand wrote: > > On 28.11.22 09:17, Hans Verkuil wrote: > > Hi David, > > > > On 27/11/2022 11:35, David Hildenbrand wrote: > >> On 16.11.22 11:26, David Hildenbrand wrote: > >>> FOLL_FORCE is really only for ptrace access. According to commit > >>> 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are always > >>> writable"), get_vaddr_frames() currently pins all pages writable as a > >>> workaround for issues with read-only buffers. > >>> > >>> FOLL_FORCE, however, seems to be a legacy leftover as it predates > >>> commit 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are > >>> always writable"). Let's just remove it. > >>> > >>> Once the read-only buffer issue has been resolved, FOLL_WRITE could > >>> again be set depending on the DMA direction. > >>> > >>> Cc: Hans Verkuil > >>> Cc: Marek Szyprowski > >>> Cc: Tomasz Figa > >>> Cc: Marek Szyprowski > >>> Cc: Mauro Carvalho Chehab > >>> Signed-off-by: David Hildenbrand > >>> --- > >>> drivers/media/common/videobuf2/frame_vector.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/media/common/videobuf2/frame_vector.c b/drivers/media/common/videobuf2/frame_vector.c > >>> index 542dde9d2609..062e98148c53 100644 > >>> --- a/drivers/media/common/videobuf2/frame_vector.c > >>> +++ b/drivers/media/common/videobuf2/frame_vector.c > >>> @@ -50,7 +50,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, > >>> start = untagged_addr(start); > >>> ret = pin_user_pages_fast(start, nr_frames, > >>> - FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM, > >>> + FOLL_WRITE | FOLL_LONGTERM, > >>> (struct page **)(vec->ptrs)); > >>> if (ret > 0) { > >>> vec->got_ref = true; > >> > >> > >> Hi Andrew, > >> > >> see the discussion at [1] regarding a conflict and how to proceed with > >> upstreaming. The conflict would be easy to resolve, however, also > >> the patch description doesn't make sense anymore with [1]. > > > > Might it be easier and less confusing if you post a v2 of this series > > with my patch first? That way it is clear that 1) my patch has to come > > first, and 2) that it is part of a single series and should be merged > > by the mm subsystem. > > > > Less chances of things going wrong that way. > > > > Just mention in the v2 cover letter that the first patch was added to > > make it easy to backport that fix without being hampered by merge > > conflicts if it was added after your frame_vector.c patch. > > Yes, that's the way I would naturally do, it, however, Andrew prefers > delta updates for minor changes. > > @Andrew, whatever you prefer! > > Thanks! > However you folks proceed with taking this patch, feel free to add my Acked-by. Thanks! Best regards, Tomasz > -- > Thanks, > > David / dhildenb > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DE30BC47089 for ; Mon, 28 Nov 2022 08:58:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=4Xu3ellfg2Kv2+5nnTPSyy1gJNaG0Of5Xxq7wu34dIU=; b=zn1Kra2SIf5DJq g/Z+k4ey1uWJpaGhwkiqSjT0KMTY06UaMq54OpoTiYWACtVn87kWpM6QftYCFjmJbaKUVzZbSSE/f cGLY5SB7Ij7/oQ6nqnShFYf2P7x17LgXpvFehJM0DOOTOn5Lhy1p/cHDo2gPQi8stGxR5mwtTKHu0 Br6foHBgNRU+Dk+5ryB1i/bX1H83ftoBAlTmulHwDzS288WuURGQM1NpkVd/KNmEP6iojNaPHY2Po m3vp3WV9TJGcOKu5UicbMlfT8FpPKPNHmi07mUHj0zvqzSEljbO5LwylksmGGoYPoMb9pd2f/3Z7L kancRVFywPTVu66e2rQw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ozZxs-000RIj-Fm; Mon, 28 Nov 2022 08:58:12 +0000 Received: from mail-ed1-x530.google.com ([2a00:1450:4864:20::530]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ozZxq-000RGo-8l for linux-um@lists.infradead.org; Mon, 28 Nov 2022 08:58:11 +0000 Received: by mail-ed1-x530.google.com with SMTP id s12so14462222edd.5 for ; Mon, 28 Nov 2022 00:58:07 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.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=iRo5DYRndKCx9sGSXzsZxPr88K/zqtuLTLl1O32mcFE=; b=XOKEpyQaMH8DtU4ghoeum5LLPSyZKKSeL9ukREYJEhE5Pet4ng53VcgxrNVIVOiN3z qM9BvX69vBwubqV7gI66eEPgV5zFoyHzRXj6Y/c3o1k6BVytkDV23dS8hW9lN3urO8Q7 YycsWj1XAMOHph6L7v2J+A4VSfKO7i7WBHunk= 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=iRo5DYRndKCx9sGSXzsZxPr88K/zqtuLTLl1O32mcFE=; b=K6vIPhQeTpLMpl95jWuklnfYtWdtxen0DBb28/QrIHZm8hMuynm8TeWJwEZ6f7W/d1 j4fd3F2iyFhyAK6WtOka6gX1DxKMbVyJTyzQqN/azMIg6dOBdWU+Z1pMK7OdLnI3V/Ij K5YyGiv8RM1cMXDhjmjRvxWg6xv0cSOFQWXMxbyPo7/k8PvECeIyDAxL7nf+eRfRiOTu xHqRfUMnF5FXVjCTjCF6kie259ug/0DzJQvTLK8gvpIWDU3kBiTH/aCcYZdaAj5Z3Mt2 lSm9TLG47gddK5MoDT/7rnq6fMw0HoNE/olmyoax/viIXFnVVrniRypzpIuAmfnpavJ7 e+3w== X-Gm-Message-State: ANoB5pnVZFHbr2DM4ChnYdZUrdXGkmaMIMqEa/HDSBceyZzCMdnEROG/ 4DoRNDwDHR4eW0A5Gk8ykIXtRbBbWIXlYg== X-Google-Smtp-Source: AA0mqf6tjB7QJncK0DxuyXA9mDeX2Zpx3PN19g8CMuXVcSft6y8g8JPPItzG0F/eY45EKJnlCwnGNw== X-Received: by 2002:a05:6402:207b:b0:46a:dd61:b927 with SMTP id bd27-20020a056402207b00b0046add61b927mr11045406edb.218.1669625885875; Mon, 28 Nov 2022 00:58:05 -0800 (PST) Received: from mail-ed1-f50.google.com (mail-ed1-f50.google.com. [209.85.208.50]) by smtp.gmail.com with ESMTPSA id f20-20020a056402069400b00463bc1ddc76sm4920112edy.28.2022.11.28.00.58.04 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 28 Nov 2022 00:58:05 -0800 (PST) Received: by mail-ed1-f50.google.com with SMTP id z18so14441564edb.9 for ; Mon, 28 Nov 2022 00:58:04 -0800 (PST) X-Received: by 2002:aa7:db98:0:b0:46a:d57:d9d0 with SMTP id u24-20020aa7db98000000b0046a0d57d9d0mr25216647edt.113.1669625884043; Mon, 28 Nov 2022 00:58:04 -0800 (PST) MIME-Version: 1.0 References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-17-david@redhat.com> <81fb0fa3-2e06-b765-56ac-a7d981194e59@redhat.com> <08b65ac6-6786-1080-18f8-d2be109c85fc@xs4all.nl> <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> In-Reply-To: <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> From: Tomasz Figa Date: Mon, 28 Nov 2022 17:57:51 +0900 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH mm-unstable v1 16/20] mm/frame-vector: remove FOLL_FORCE usage To: David Hildenbrand Cc: Hans Verkuil , linux-kernel@vger.kernel.org, Andrew Morton , x86@kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-perf-users@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kselftest@vger.kernel.org, Linus Torvalds , Jason Gunthorpe , John Hubbard , Peter Xu , Greg Kroah-Hartman , Andrea Arcangeli , Hugh Dickins , Nadav Amit , Vlastimil Babka , Matthew Wilcox , Mike Kravetz , Muchun Song , Shuah Khan , Lucas Stach , David Airlie , Oded Gabbay , Arnd Bergmann , Christoph Hellwig , Alex Williamson , Marek Szyprowski , Mauro Carvalho Chehab X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221128_005810_334502_20E6F590 X-CRM114-Status: GOOD ( 32.42 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org On Mon, Nov 28, 2022 at 5:19 PM David Hildenbrand wrote: > > On 28.11.22 09:17, Hans Verkuil wrote: > > Hi David, > > > > On 27/11/2022 11:35, David Hildenbrand wrote: > >> On 16.11.22 11:26, David Hildenbrand wrote: > >>> FOLL_FORCE is really only for ptrace access. According to commit > >>> 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are always > >>> writable"), get_vaddr_frames() currently pins all pages writable as a > >>> workaround for issues with read-only buffers. > >>> > >>> FOLL_FORCE, however, seems to be a legacy leftover as it predates > >>> commit 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are > >>> always writable"). Let's just remove it. > >>> > >>> Once the read-only buffer issue has been resolved, FOLL_WRITE could > >>> again be set depending on the DMA direction. > >>> > >>> Cc: Hans Verkuil > >>> Cc: Marek Szyprowski > >>> Cc: Tomasz Figa > >>> Cc: Marek Szyprowski > >>> Cc: Mauro Carvalho Chehab > >>> Signed-off-by: David Hildenbrand > >>> --- > >>> drivers/media/common/videobuf2/frame_vector.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/media/common/videobuf2/frame_vector.c b/drivers/media/common/videobuf2/frame_vector.c > >>> index 542dde9d2609..062e98148c53 100644 > >>> --- a/drivers/media/common/videobuf2/frame_vector.c > >>> +++ b/drivers/media/common/videobuf2/frame_vector.c > >>> @@ -50,7 +50,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, > >>> start = untagged_addr(start); > >>> ret = pin_user_pages_fast(start, nr_frames, > >>> - FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM, > >>> + FOLL_WRITE | FOLL_LONGTERM, > >>> (struct page **)(vec->ptrs)); > >>> if (ret > 0) { > >>> vec->got_ref = true; > >> > >> > >> Hi Andrew, > >> > >> see the discussion at [1] regarding a conflict and how to proceed with > >> upstreaming. The conflict would be easy to resolve, however, also > >> the patch description doesn't make sense anymore with [1]. > > > > Might it be easier and less confusing if you post a v2 of this series > > with my patch first? That way it is clear that 1) my patch has to come > > first, and 2) that it is part of a single series and should be merged > > by the mm subsystem. > > > > Less chances of things going wrong that way. > > > > Just mention in the v2 cover letter that the first patch was added to > > make it easy to backport that fix without being hampered by merge > > conflicts if it was added after your frame_vector.c patch. > > Yes, that's the way I would naturally do, it, however, Andrew prefers > delta updates for minor changes. > > @Andrew, whatever you prefer! > > Thanks! > However you folks proceed with taking this patch, feel free to add my Acked-by. Thanks! Best regards, Tomasz > -- > Thanks, > > David / dhildenb > _______________________________________________ linux-um mailing list linux-um@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-um From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Figa Date: Mon, 28 Nov 2022 08:57:51 +0000 Subject: Re: [PATCH mm-unstable v1 16/20] mm/frame-vector: remove FOLL_FORCE usage Message-Id: List-Id: References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-17-david@redhat.com> <81fb0fa3-2e06-b765-56ac-a7d981194e59@redhat.com> <08b65ac6-6786-1080-18f8-d2be109c85fc@xs4all.nl> <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> In-Reply-To: <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Hildenbrand Cc: Hans Verkuil , linux-kernel@vger.kernel.org, Andrew Morton , x86@kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-perf-users@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kselftest@vger.kernel.org, Linus Torvalds , Jason Gunthorpe , John Hubbard , Peter Xu , Greg Kroah-Hartman , Andrea Arcangeli , Hugh Dickins , Nadav Amit , Vlastimil Babka , Matthew Wilcox , Mike Kravetz , Muchun Song , Shuah Khan , Lucas Stach , David Airlie , Oded Gabbay , Arnd Bergmann , Christoph Hellwig , Alex Williamson , Marek Szyprowski , Mauro Carvalho Chehab On Mon, Nov 28, 2022 at 5:19 PM David Hildenbrand wrote: > > On 28.11.22 09:17, Hans Verkuil wrote: > > Hi David, > > > > On 27/11/2022 11:35, David Hildenbrand wrote: > >> On 16.11.22 11:26, David Hildenbrand wrote: > >>> FOLL_FORCE is really only for ptrace access. According to commit > >>> 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are always > >>> writable"), get_vaddr_frames() currently pins all pages writable as a > >>> workaround for issues with read-only buffers. > >>> > >>> FOLL_FORCE, however, seems to be a legacy leftover as it predates > >>> commit 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are > >>> always writable"). Let's just remove it. > >>> > >>> Once the read-only buffer issue has been resolved, FOLL_WRITE could > >>> again be set depending on the DMA direction. > >>> > >>> Cc: Hans Verkuil > >>> Cc: Marek Szyprowski > >>> Cc: Tomasz Figa > >>> Cc: Marek Szyprowski > >>> Cc: Mauro Carvalho Chehab > >>> Signed-off-by: David Hildenbrand > >>> --- > >>> drivers/media/common/videobuf2/frame_vector.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/media/common/videobuf2/frame_vector.c b/drivers/media/common/videobuf2/frame_vector.c > >>> index 542dde9d2609..062e98148c53 100644 > >>> --- a/drivers/media/common/videobuf2/frame_vector.c > >>> +++ b/drivers/media/common/videobuf2/frame_vector.c > >>> @@ -50,7 +50,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, > >>> start = untagged_addr(start); > >>> ret = pin_user_pages_fast(start, nr_frames, > >>> - FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM, > >>> + FOLL_WRITE | FOLL_LONGTERM, > >>> (struct page **)(vec->ptrs)); > >>> if (ret > 0) { > >>> vec->got_ref = true; > >> > >> > >> Hi Andrew, > >> > >> see the discussion at [1] regarding a conflict and how to proceed with > >> upstreaming. The conflict would be easy to resolve, however, also > >> the patch description doesn't make sense anymore with [1]. > > > > Might it be easier and less confusing if you post a v2 of this series > > with my patch first? That way it is clear that 1) my patch has to come > > first, and 2) that it is part of a single series and should be merged > > by the mm subsystem. > > > > Less chances of things going wrong that way. > > > > Just mention in the v2 cover letter that the first patch was added to > > make it easy to backport that fix without being hampered by merge > > conflicts if it was added after your frame_vector.c patch. > > Yes, that's the way I would naturally do, it, however, Andrew prefers > delta updates for minor changes. > > @Andrew, whatever you prefer! > > Thanks! > However you folks proceed with taking this patch, feel free to add my Acked-by. Thanks! Best regards, Tomasz > -- > Thanks, > > David / dhildenb > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Figa Subject: Re: [PATCH mm-unstable v1 16/20] mm/frame-vector: remove FOLL_FORCE usage Date: Mon, 28 Nov 2022 17:57:51 +0900 Message-ID: References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-17-david@redhat.com> <81fb0fa3-2e06-b765-56ac-a7d981194e59@redhat.com> <08b65ac6-6786-1080-18f8-d2be109c85fc@xs4all.nl> <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.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=iRo5DYRndKCx9sGSXzsZxPr88K/zqtuLTLl1O32mcFE=; b=XOKEpyQaMH8DtU4ghoeum5LLPSyZKKSeL9ukREYJEhE5Pet4ng53VcgxrNVIVOiN3z qM9BvX69vBwubqV7gI66eEPgV5zFoyHzRXj6Y/c3o1k6BVytkDV23dS8hW9lN3urO8Q7 YycsWj1XAMOHph6L7v2J+A4VSfKO7i7WBHunk= In-Reply-To: <9d0bf98a-3d6a-1082-e992-1338e1525935@redhat.com> List-ID: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Hildenbrand Cc: Hans Verkuil , linux-kernel@vger.kernel.org, Andrew Morton , x86@kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-ia64@vger.kernel.org, linux-mips@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, sparclinux@vger.kernel.org, linux-um@lists.infradead.org, etnaviv@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, linux-rdma@vger.kernel.org, linux-media@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-perf-users@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kselftest@vger.kernel.org, Linus Torvalds , Jason Gunthorpe , John Hubbard , Peter Xu

On Mon, Nov 28, 2022 at 5:19 PM David Hildenbrand wrote: > > On 28.11.22 09:17, Hans Verkuil wrote: > > Hi David, > > > > On 27/11/2022 11:35, David Hildenbrand wrote: > >> On 16.11.22 11:26, David Hildenbrand wrote: > >>> FOLL_FORCE is really only for ptrace access. According to commit > >>> 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are always > >>> writable"), get_vaddr_frames() currently pins all pages writable as a > >>> workaround for issues with read-only buffers. > >>> > >>> FOLL_FORCE, however, seems to be a legacy leftover as it predates > >>> commit 707947247e95 ("media: videobuf2-vmalloc: get_userptr: buffers are > >>> always writable"). Let's just remove it. > >>> > >>> Once the read-only buffer issue has been resolved, FOLL_WRITE could > >>> again be set depending on the DMA direction. > >>> > >>> Cc: Hans Verkuil > >>> Cc: Marek Szyprowski > >>> Cc: Tomasz Figa > >>> Cc: Marek Szyprowski > >>> Cc: Mauro Carvalho Chehab > >>> Signed-off-by: David Hildenbrand > >>> --- > >>> drivers/media/common/videobuf2/frame_vector.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/drivers/media/common/videobuf2/frame_vector.c b/drivers/media/common/videobuf2/frame_vector.c > >>> index 542dde9d2609..062e98148c53 100644 > >>> --- a/drivers/media/common/videobuf2/frame_vector.c > >>> +++ b/drivers/media/common/videobuf2/frame_vector.c > >>> @@ -50,7 +50,7 @@ int get_vaddr_frames(unsigned long start, unsigned int nr_frames, > >>> start = untagged_addr(start); > >>> ret = pin_user_pages_fast(start, nr_frames, > >>> - FOLL_FORCE | FOLL_WRITE | FOLL_LONGTERM, > >>> + FOLL_WRITE | FOLL_LONGTERM, > >>> (struct page **)(vec->ptrs)); > >>> if (ret > 0) { > >>> vec->got_ref = true; > >> > >> > >> Hi Andrew, > >> > >> see the discussion at [1] regarding a conflict and how to proceed with > >> upstreaming. The conflict would be easy to resolve, however, also > >> the patch description doesn't make sense anymore with [1]. > > > > Might it be easier and less confusing if you post a v2 of this series > > with my patch first? That way it is clear that 1) my patch has to come > > first, and 2) that it is part of a single series and should be merged > > by the mm subsystem. > > > > Less chances of things going wrong that way. > > > > Just mention in the v2 cover letter that the first patch was added to > > make it easy to backport that fix without being hampered by merge > > conflicts if it was added after your frame_vector.c patch. > > Yes, that's the way I would naturally do, it, however, Andrew prefers > delta updates for minor changes. > > @Andrew, whatever you prefer! > > Thanks! > However you folks proceed with taking this patch, feel free to add my Acked-by. Thanks! Best regards, Tomasz > -- > Thanks, > > David / dhildenb >