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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B71DC43219 for ; Wed, 16 Nov 2022 11:04:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233433AbiKPLEf (ORCPT ); Wed, 16 Nov 2022 06:04:35 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49538 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238461AbiKPLEU (ORCPT ); Wed, 16 Nov 2022 06:04:20 -0500 Received: from mail-ej1-x636.google.com (mail-ej1-x636.google.com [IPv6:2a00:1450:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7324449B6B for ; Wed, 16 Nov 2022 02:50:35 -0800 (PST) Received: by mail-ej1-x636.google.com with SMTP id ft34so43006760ejc.12 for ; Wed, 16 Nov 2022 02:50:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date:from:to:cc :subject:date:message-id:reply-to; bh=mdwJ/650wADnRoR72oyZkQ8DiIzSWQSpq6IdxtCR+gY=; b=f2SpOZdEZzXCSPn0ykm1oJX1As7I6xxh5wr16pOd/kbA5OOiuO0Y4IWH35k28OjNoj wHiTHItpgbOeFMLRaKE+zMy2u3TZ9N8dtmICEQujo3Me7a5E74OF+31ufRLy1oYVFEA1 T3Nbw0vHjZlr/vzIiD2dpwD9w/oFbF5Q800Lc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=mdwJ/650wADnRoR72oyZkQ8DiIzSWQSpq6IdxtCR+gY=; b=kHOKZdUwojdY8KWPmb1YzUAPBMl01EGilHvt1c2ziRFPz3DDokZjR5B0+83nHdyFPR jYEP4QyogQOzGouAkoeIQ5rfe8JpOcLcejONz7g5Y2mMEBRIvJHH4Q63T5Mqpl66g8uu x6tCr4YyZJr18LwvhPlEDwIZnHzogUiOjheuECU8vwjvTM44XGVkZ1i7R5fs7N8c6461 Os9B8jq148p2/BfIc55GiS8a3gIVbeRqsLs2iAkbc/fYGOO2nEUmQCDJGscxisO3HhGV 53NpbNM8NWG7fkMPec4b2Sbr5UI7ODLSK/dVQEVvSMoWvzNuzseqbIuD+VU+4Gfj30wj q8Zw== X-Gm-Message-State: ANoB5plkf9QCkF8HjxXFpWRaGmW2+rU3Wf8LgMm+GHk7YVeCmneRXIe2 piZbGWa9N7gO4H0rKmypAaoqdg== X-Google-Smtp-Source: AA0mqf4MgV0oW/LCUugReHUpBkpepoZ7Vy6UeNXMZ5Yjky+iNhPczOtY8K1ul1dtRtcsoxT6/N3VKQ== X-Received: by 2002:a17:906:78e:b0:7a1:e52e:bddb with SMTP id l14-20020a170906078e00b007a1e52ebddbmr16502698ejc.685.1668595834073; Wed, 16 Nov 2022 02:50:34 -0800 (PST) Received: from phenom.ffwll.local (212-51-149-33.fiber7.init7.net. [212.51.149.33]) by smtp.gmail.com with ESMTPSA id jw17-20020a17090776b100b0078b1ff41f05sm6758790ejc.43.2022.11.16.02.50.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Nov 2022 02:50:33 -0800 (PST) Date: Wed, 16 Nov 2022 11:50:31 +0100 From: Daniel Vetter To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, Greg Kroah-Hartman , dri-devel@lists.freedesktop.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-mips@vger.kernel.org, Tomasz Figa , 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 Subject: Re: [PATCH mm-unstable v1 16/20] mm/frame-vector: remove FOLL_FORCE usage Message-ID: Mail-Followup-To: David Hildenbrand , linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, Greg Kroah-Hartman , dri-devel@lists.freedesktop.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-mips@vger.kernel.org, Tomasz Figa , 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 References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-17-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221116102659.70287-17-david@redhat.com> X-Operating-System: Linux phenom 5.19.0-2-amd64 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Wed, Nov 16, 2022 at 11:26:55AM +0100, 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 Also code I looked at while looking at follow_pfn stuff Reviewed-by: Daniel Vetter > --- > 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; > -- > 2.38.1 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch 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 39FDDC4332F for ; Wed, 16 Nov 2022 10:50:42 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 0391F10E474; Wed, 16 Nov 2022 10:50:40 +0000 (UTC) Received: from mail-ej1-x636.google.com (mail-ej1-x636.google.com [IPv6:2a00:1450:4864:20::636]) by gabe.freedesktop.org (Postfix) with ESMTPS id 79CDB10E477 for ; Wed, 16 Nov 2022 10:50:35 +0000 (UTC) Received: by mail-ej1-x636.google.com with SMTP id f27so43150454eje.1 for ; Wed, 16 Nov 2022 02:50:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date:from:to:cc :subject:date:message-id:reply-to; bh=mdwJ/650wADnRoR72oyZkQ8DiIzSWQSpq6IdxtCR+gY=; b=f2SpOZdEZzXCSPn0ykm1oJX1As7I6xxh5wr16pOd/kbA5OOiuO0Y4IWH35k28OjNoj wHiTHItpgbOeFMLRaKE+zMy2u3TZ9N8dtmICEQujo3Me7a5E74OF+31ufRLy1oYVFEA1 T3Nbw0vHjZlr/vzIiD2dpwD9w/oFbF5Q800Lc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=mdwJ/650wADnRoR72oyZkQ8DiIzSWQSpq6IdxtCR+gY=; b=XsWcyZLOnN4Gg+0AoksWnKQUrL1Z+5UV5JiZ9rfnGcK1T2AjtqTucWW3Hi/uuCItMl Yj33toVnyb20EPSSs762390TtkahUJ22aiydJs4skaAzIz7JWm0pm1SFBMo1W8Ckp7qJ sG1V4HkfYI8yvHcZ0dt0XcWdM77scPQGw/RNLpPFIxUlMFW8+R9acx9tS+UcpLsrnchw f+WwR9ixC2SpukY7K2M5UsKogaVVyF9Dui2JE90lWHhjn5c92OkiXsY0KRmN/YJRoM3+ G5C0RVvSG+r9QVnheG+4XCM2Mh6v1mG3Yy0WLiwLIM7A3XiEga5Aj41DjzRGBxKTYPHC wB1w== X-Gm-Message-State: ANoB5plOW2VFvJMyA8EWgYu4h+gtRHuiQRrdzb7NFP/P4uVshnnuttq6 XOoTMMexBAO+40Digx3iGaRJWA== X-Google-Smtp-Source: AA0mqf4MgV0oW/LCUugReHUpBkpepoZ7Vy6UeNXMZ5Yjky+iNhPczOtY8K1ul1dtRtcsoxT6/N3VKQ== X-Received: by 2002:a17:906:78e:b0:7a1:e52e:bddb with SMTP id l14-20020a170906078e00b007a1e52ebddbmr16502698ejc.685.1668595834073; Wed, 16 Nov 2022 02:50:34 -0800 (PST) Received: from phenom.ffwll.local (212-51-149-33.fiber7.init7.net. [212.51.149.33]) by smtp.gmail.com with ESMTPSA id jw17-20020a17090776b100b0078b1ff41f05sm6758790ejc.43.2022.11.16.02.50.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Nov 2022 02:50:33 -0800 (PST) Date: Wed, 16 Nov 2022 11:50:31 +0100 From: Daniel Vetter To: David Hildenbrand Subject: Re: [PATCH mm-unstable v1 16/20] mm/frame-vector: remove FOLL_FORCE usage Message-ID: Mail-Followup-To: David Hildenbrand , linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, Greg Kroah-Hartman , dri-devel@lists.freedesktop.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-mips@vger.kernel.org, Tomasz Figa , 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 References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-17-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221116102659.70287-17-david@redhat.com> X-Operating-System: Linux phenom 5.19.0-2-amd64 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, 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 , linux-arm-kernel@lists.infradead.org, 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 , Vlastimil Babka , Greg Kroah-Hartman , Oded Gabbay , Linus Torvalds , linux-kernel@vger.kernel.org, Tomasz Figa , linux-perf-users@vger.kernel.org, linux-security-module@vger.kernel.org, linux-alpha@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , linuxppc-dev@lists.ozlabs.org, Mike Kravetz Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" On Wed, Nov 16, 2022 at 11:26:55AM +0100, 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 Also code I looked at while looking at follow_pfn stuff Reviewed-by: Daniel Vetter > --- > 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; > -- > 2.38.1 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch 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 E1AEAC433FE for ; Wed, 16 Nov 2022 10:54:48 +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:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=3PUfwn0xsitQ/cxxEmqMaHpTif14xum74pAW1oM6v5I=; b=HXm1iDVWxzQyML kbzpEdtDSW36T+j8Yl8lATRp0EPfU+te+rriv63ZpJrQ3nidJi+5zSSXrly2XEoAx/Z8u6bGCCCah 2g0IcdeOZNDAf83GHQK61g7JomPHjUTlmdsHfN5oFyxIJ7uNMUQZ354PUduHhlca5Kb+ZzfSeLeMO SwFadVDFa4sVOI5wCcB6u3wX/1CB0DMls5m+Qf8Vf33Y3akpPcCOnXSLLdoZXt9tBnE7XkybkdQPE kek1RsQ5QGrAdq8ov/wkR4uwnLcLzeN6S71wKS/dv63xlQhtecYDlDnc9NreHUoUipqpXV/rD6O6W EVyqVP1ghKuo1PovPjDQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ovG2V-002Tui-N1; Wed, 16 Nov 2022 10:53:08 +0000 Received: from mail-ej1-x62c.google.com ([2a00:1450:4864:20::62c]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ovG05-002S6C-AX for linux-arm-kernel@lists.infradead.org; Wed, 16 Nov 2022 10:50:39 +0000 Received: by mail-ej1-x62c.google.com with SMTP id n21so2347326ejb.9 for ; Wed, 16 Nov 2022 02:50:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date:from:to:cc :subject:date:message-id:reply-to; bh=mdwJ/650wADnRoR72oyZkQ8DiIzSWQSpq6IdxtCR+gY=; b=f2SpOZdEZzXCSPn0ykm1oJX1As7I6xxh5wr16pOd/kbA5OOiuO0Y4IWH35k28OjNoj wHiTHItpgbOeFMLRaKE+zMy2u3TZ9N8dtmICEQujo3Me7a5E74OF+31ufRLy1oYVFEA1 T3Nbw0vHjZlr/vzIiD2dpwD9w/oFbF5Q800Lc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=mdwJ/650wADnRoR72oyZkQ8DiIzSWQSpq6IdxtCR+gY=; b=6b5qHzDouhuv9YlirGTQlUSrsa5F7+9o8HotoQ46NO7wYtpeBKC7wioS08thmWvQb8 oX3ZeZjCeT8lIrG679X669bCJjE3+c+4w5r7+jbRN5tSWuhJCHlDHPUIuy3Iqm06ZTnL Fe0WxsD0REDaWWAdXBPTCGPMEa104z93M7vOqDNTH4egC6v6J6SGY7UHGvsSrDFz+NK4 8VkajNrUxj+sd8wdAV3EVHIXgUDRBPDIrcKzn9k/Ak+hZsBFd+HamCAH3xwN+OTtGo60 WYFfD3qkrtkfSjDurFirCAhxNn2L8duvJ/b9KDk+e7N/6qNyuXPs5PExVKNDljnEwZJ9 nFPw== X-Gm-Message-State: ANoB5pkmVorgOsHBZVWfBRrrrewaw5R6XRdrnGkIvAF8j1NCNXbVdD/g K9klxzWSzpG80kq7ZkZ5eQRyBA== X-Google-Smtp-Source: AA0mqf4MgV0oW/LCUugReHUpBkpepoZ7Vy6UeNXMZ5Yjky+iNhPczOtY8K1ul1dtRtcsoxT6/N3VKQ== X-Received: by 2002:a17:906:78e:b0:7a1:e52e:bddb with SMTP id l14-20020a170906078e00b007a1e52ebddbmr16502698ejc.685.1668595834073; Wed, 16 Nov 2022 02:50:34 -0800 (PST) Received: from phenom.ffwll.local (212-51-149-33.fiber7.init7.net. [212.51.149.33]) by smtp.gmail.com with ESMTPSA id jw17-20020a17090776b100b0078b1ff41f05sm6758790ejc.43.2022.11.16.02.50.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Nov 2022 02:50:33 -0800 (PST) Date: Wed, 16 Nov 2022 11:50:31 +0100 From: Daniel Vetter To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, Greg Kroah-Hartman , dri-devel@lists.freedesktop.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-mips@vger.kernel.org, Tomasz Figa , 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 Subject: Re: [PATCH mm-unstable v1 16/20] mm/frame-vector: remove FOLL_FORCE usage Message-ID: Mail-Followup-To: David Hildenbrand , linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, Greg Kroah-Hartman , dri-devel@lists.freedesktop.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-mips@vger.kernel.org, Tomasz Figa , 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 References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-17-david@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20221116102659.70287-17-david@redhat.com> X-Operating-System: Linux phenom 5.19.0-2-amd64 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221116_025037_418590_3FB6E35D X-CRM114-Status: GOOD ( 25.24 ) 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 Wed, Nov 16, 2022 at 11:26:55AM +0100, 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 Also code I looked at while looking at follow_pfn stuff Reviewed-by: Daniel Vetter > --- > 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; > -- > 2.38.1 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ 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 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 CFB85C4332F for ; Wed, 16 Nov 2022 10:51:43 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4NC0Gk1tVDz3fLg for ; Wed, 16 Nov 2022 21:51:42 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; secure) header.d=ffwll.ch header.i=@ffwll.ch header.a=rsa-sha256 header.s=google header.b=f2SpOZdE; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=ffwll.ch (client-ip=2a00:1450:4864:20::634; helo=mail-ej1-x634.google.com; envelope-from=daniel@ffwll.ch; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; secure) header.d=ffwll.ch header.i=@ffwll.ch header.a=rsa-sha256 header.s=google header.b=f2SpOZdE; dkim-atps=neutral Received: from mail-ej1-x634.google.com (mail-ej1-x634.google.com [IPv6:2a00:1450:4864:20::634]) (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 4NC0FV117bz3fFP for ; Wed, 16 Nov 2022 21:50:37 +1100 (AEDT) Received: by mail-ej1-x634.google.com with SMTP id gv23so10364260ejb.3 for ; Wed, 16 Nov 2022 02:50:37 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date:from:to:cc :subject:date:message-id:reply-to; bh=mdwJ/650wADnRoR72oyZkQ8DiIzSWQSpq6IdxtCR+gY=; b=f2SpOZdEZzXCSPn0ykm1oJX1As7I6xxh5wr16pOd/kbA5OOiuO0Y4IWH35k28OjNoj wHiTHItpgbOeFMLRaKE+zMy2u3TZ9N8dtmICEQujo3Me7a5E74OF+31ufRLy1oYVFEA1 T3Nbw0vHjZlr/vzIiD2dpwD9w/oFbF5Q800Lc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=mdwJ/650wADnRoR72oyZkQ8DiIzSWQSpq6IdxtCR+gY=; b=zhk4OoiKXdhDwjcuV+GRNyElLQ5IF1LvK+H2RosQVYmcskKAXkF+KC86eP2TNPtHE6 IBmP44IlJySw3peK7sxWWXJ7UTIdENC/RddaycwrpYwdVb01XmTSSX8VArerd2Z01gb6 iBcieDTFKAJA+dfqB05DZnqpG5863NtA45I++4tZCre98za69CzqFVNYfcf8jGpwKmmT we873yj5PD3QbUdvWk2mH8vRV+n+DKI3jbe9UHhmQQYGPU0DmaZZbSUIezhl6HAhQZHI R/6Fo8m+UXkHreej7eUs8tkTaaChr/gZxYqjeExrHALUff0wri6bR40YtMtxohNibKZk nHNg== X-Gm-Message-State: ANoB5pkZWLi0wimhwJmSFUUJSFucdz/yiVg2Aut1TUBqUAj0xg+g99B/ gpFSqOmxX3Obk1d63f5vtvleuw== X-Google-Smtp-Source: AA0mqf4MgV0oW/LCUugReHUpBkpepoZ7Vy6UeNXMZ5Yjky+iNhPczOtY8K1ul1dtRtcsoxT6/N3VKQ== X-Received: by 2002:a17:906:78e:b0:7a1:e52e:bddb with SMTP id l14-20020a170906078e00b007a1e52ebddbmr16502698ejc.685.1668595834073; Wed, 16 Nov 2022 02:50:34 -0800 (PST) Received: from phenom.ffwll.local (212-51-149-33.fiber7.init7.net. [212.51.149.33]) by smtp.gmail.com with ESMTPSA id jw17-20020a17090776b100b0078b1ff41f05sm6758790ejc.43.2022.11.16.02.50.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Nov 2022 02:50:33 -0800 (PST) Date: Wed, 16 Nov 2022 11:50:31 +0100 From: Daniel Vetter To: David Hildenbrand Subject: Re: [PATCH mm-unstable v1 16/20] mm/frame-vector: remove FOLL_FORCE usage Message-ID: Mail-Followup-To: David Hildenbrand , linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, Greg Kroah-Hartman , dri-devel@lists.freedesktop.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-mips@vger.kernel.org, Tomasz Figa , 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 References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-17-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221116102659.70287-17-david@redhat.com> X-Operating-System: Linux phenom 5.19.0-2-amd64 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, 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 , linux-arm-kernel@lists.infradead.org, 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 , Vlastimil Babka , Greg Kroah-Hartman , Oded Gabbay , Linus Torvalds , linux-kernel@vger.kernel.org, Tomasz Figa , linux-perf-users@vger.kernel.org, linux-security-module@vger.kernel.org, linux-alpha@vger.kernel.org, linux-fsdevel@vger.kernel.org, Andrew Morton , linuxppc-dev@lists.ozlabs.org, Mike Kravetz Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Wed, Nov 16, 2022 at 11:26:55AM +0100, 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 Also code I looked at while looking at follow_pfn stuff Reviewed-by: Daniel Vetter > --- > 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; > -- > 2.38.1 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch 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 D9B37C4332F for ; Wed, 16 Nov 2022 10:53:05 +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:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=IPv/MBLVsWFI/bygMWZ+XFPX7Wg7UJ9RuzOnwhaWq5M=; b=CRyHN2EIsKGCfd a1xUJfxAbFT1JxX1iVD3ev1F5BcqChACZxtJFFzYb424PXTRbrO4KBTrer0iSMdKR8nbNeI1jS+Bb apA0i2OVwr6/881LgQLCxURlkFYpIm/NKwRgh8wvBnWoPEAn4oJIVVl7JeAXjSB9v2mHiPgSSeUTp 0Q9MfLmPGNzgioQm9L82dzVNzbIaka1zz5RvuHmWREHCMc1zvQbw7WBoCKKhULaC4WPsKf3nWx9Cn O74Lt5Nl2yEUINBOf+OZn796rJWBtj7HI70lvtVRS/QNCOZvIAOk/RaPn3m5G8n5j1qNDt56zhiO/ LPo+CfJ0o8KGh5OSw9RQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1ovG2S-002Tts-Rh; Wed, 16 Nov 2022 10:53:04 +0000 Received: from mail-ej1-x636.google.com ([2a00:1450:4864:20::636]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1ovG04-002S6B-BL for linux-um@lists.infradead.org; Wed, 16 Nov 2022 10:50:37 +0000 Received: by mail-ej1-x636.google.com with SMTP id i10so34426502ejg.6 for ; Wed, 16 Nov 2022 02:50:35 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date:from:to:cc :subject:date:message-id:reply-to; bh=mdwJ/650wADnRoR72oyZkQ8DiIzSWQSpq6IdxtCR+gY=; b=f2SpOZdEZzXCSPn0ykm1oJX1As7I6xxh5wr16pOd/kbA5OOiuO0Y4IWH35k28OjNoj wHiTHItpgbOeFMLRaKE+zMy2u3TZ9N8dtmICEQujo3Me7a5E74OF+31ufRLy1oYVFEA1 T3Nbw0vHjZlr/vzIiD2dpwD9w/oFbF5Q800Lc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=mdwJ/650wADnRoR72oyZkQ8DiIzSWQSpq6IdxtCR+gY=; b=oTTWshT43bIcNE2WjBVUTeJytc6PXWKMZZSw0XVWrC+Iux86iH/eY2quqlyIAr54Po qPoUnQg8AHG3EgK1GIGW3mNk77aD1Cqr8z0L4uwDC5zQePOO6wxCisR/zXqpkG9yq/TJ MpZXAIRz0gc/DiQAQceaqVUu+i/gb3lnn2Y07vKgVex9EOez7xScF4iuuLaWsAF4GkNG /Igz6LQmOw7M7eHltwI1InV7Eh6JNg0U6Ve9BIFQ8qUb+GfHxY8xKaoLmd53a20O6xlr Su/a4BOCDOaL8Dq2qxASVxX/XJJP/T9wHEXkaqxr9zF3kpKMxK5rhvL/ukF2+03bRtEy bNxg== X-Gm-Message-State: ANoB5pmsTUGPpLX+o3uhUHR3YalTsL8ptAU27xi1fksCStfR+8MzhAON pvdPPD8HF0NwhVDT6UnMo3r1Eg== X-Google-Smtp-Source: AA0mqf4MgV0oW/LCUugReHUpBkpepoZ7Vy6UeNXMZ5Yjky+iNhPczOtY8K1ul1dtRtcsoxT6/N3VKQ== X-Received: by 2002:a17:906:78e:b0:7a1:e52e:bddb with SMTP id l14-20020a170906078e00b007a1e52ebddbmr16502698ejc.685.1668595834073; Wed, 16 Nov 2022 02:50:34 -0800 (PST) Received: from phenom.ffwll.local (212-51-149-33.fiber7.init7.net. [212.51.149.33]) by smtp.gmail.com with ESMTPSA id jw17-20020a17090776b100b0078b1ff41f05sm6758790ejc.43.2022.11.16.02.50.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Nov 2022 02:50:33 -0800 (PST) Date: Wed, 16 Nov 2022 11:50:31 +0100 From: Daniel Vetter To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, Greg Kroah-Hartman , dri-devel@lists.freedesktop.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-mips@vger.kernel.org, Tomasz Figa , 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 Subject: Re: [PATCH mm-unstable v1 16/20] mm/frame-vector: remove FOLL_FORCE usage Message-ID: Mail-Followup-To: David Hildenbrand , linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, Greg Kroah-Hartman , dri-devel@lists.freedesktop.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-mips@vger.kernel.org, Tomasz Figa , 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 References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-17-david@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20221116102659.70287-17-david@redhat.com> X-Operating-System: Linux phenom 5.19.0-2-amd64 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221116_025036_440090_B0623C18 X-CRM114-Status: GOOD ( 23.89 ) 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 Wed, Nov 16, 2022 at 11:26:55AM +0100, 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 Also code I looked at while looking at follow_pfn stuff Reviewed-by: Daniel Vetter > --- > 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; > -- > 2.38.1 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch _______________________________________________ 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: Daniel Vetter Date: Wed, 16 Nov 2022 10:50:31 +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> In-Reply-To: <20221116102659.70287-17-david@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Hildenbrand Cc: linux-kernel@vger.kernel.org, linux-ia64@vger.kernel.org, Greg Kroah-Hartman , dri-devel@lists.freedesktop.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-mips@vger.kernel.org, Tomasz Figa , 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 On Wed, Nov 16, 2022 at 11:26:55AM +0100, 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 Also code I looked at while looking at follow_pfn stuff Reviewed-by: Daniel Vetter > --- > 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; > -- > 2.38.1 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Vetter Subject: Re: [PATCH mm-unstable v1 16/20] mm/frame-vector: remove FOLL_FORCE usage Date: Wed, 16 Nov 2022 11:50:31 +0100 Message-ID: References: <20221116102659.70287-1-david@redhat.com> <20221116102659.70287-17-david@redhat.com> Mime-Version: 1.0 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=in-reply-to:content-disposition:mime-version:references :mail-followup-to:message-id:subject:cc:to:from:date:from:to:cc :subject:date:message-id:reply-to; bh=mdwJ/650wADnRoR72oyZkQ8DiIzSWQSpq6IdxtCR+gY=; b=f2SpOZdEZzXCSPn0ykm1oJX1As7I6xxh5wr16pOd/kbA5OOiuO0Y4IWH35k28OjNoj wHiTHItpgbOeFMLRaKE+zMy2u3TZ9N8dtmICEQujo3Me7a5E74OF+31ufRLy1oYVFEA1 T3Nbw0vHjZlr/vzIiD2dpwD9w/oFbF5Q800Lc= Content-Disposition: inline In-Reply-To: <20221116102659.70287-17-david@redhat.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane-mx.org@lists.ozlabs.org Sender: "Linuxppc-dev" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: David Hildenbrand Cc: linux-ia64@vger.kernel.org, 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 , linux-arm-kernel@lists.infradead.org, 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 On Wed, Nov 16, 2022 at 11:26:55AM +0100, 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 Also code I looked at while looking at follow_pfn stuff Reviewed-by: Daniel Vetter > --- > 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; > -- > 2.38.1 > -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch