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