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 X-Spam-Level: X-Spam-Status: No, score=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id AE372C2D0A3 for ; Wed, 4 Nov 2020 14:00:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5514521734 for ; Wed, 4 Nov 2020 14:00:32 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="Wan5zLNC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729833AbgKDOA1 (ORCPT ); Wed, 4 Nov 2020 09:00:27 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40148 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727018AbgKDOA0 (ORCPT ); Wed, 4 Nov 2020 09:00:26 -0500 Received: from mail-qk1-x741.google.com (mail-qk1-x741.google.com [IPv6:2607:f8b0:4864:20::741]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9ABB1C061A4C for ; Wed, 4 Nov 2020 06:00:26 -0800 (PST) Received: by mail-qk1-x741.google.com with SMTP id i21so18565276qka.12 for ; Wed, 04 Nov 2020 06:00:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ziepe.ca; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=J6Nw3097qL1FGBO59AefdNEIbSIDtL/HHl1l69CFDp8=; b=Wan5zLNCc03uOg3crmJFeRaNbOEA+qwrbKwCY9LDkg1fZnFvzGEBwk4V+VLFOn5oKx tmcyGIKCw4+CD/juWp2ijPQPLgAyQG0AhFaLumt8mFw7D817cQkKUY2w7oYalFQSRaiQ Vb/ptf8IpP3WfnK3UuZPUxBAXkXY6PqsAqGNVYoZolg0yUEgsR1Di4PcNN7C/aUr2Q/R O0ZcNPr6tO0Ab4yQ9aVnuDw44g3gsPath6hDrZSj4xe9Loas/o/6/OXlQjyqG2MFoi+n R3zy4MV988W7+StxSAydki/+D4rJ/lZx0EB7vwQbsli0N+fpB6onleBpY6HTFL+CpY9E jiFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=J6Nw3097qL1FGBO59AefdNEIbSIDtL/HHl1l69CFDp8=; b=tX7QRefiZcy1rPttRq5d55zkx171X3BUPEI/VTTJpZAlrtAxeXydaG5rlubrzUn/JV sDPf42q3sn/seY6WiLWlGt0iFZZDROpAq7nx6NOTcDnh+cF00c0/g6S51ix2j2zT7WNa rqwCpDR5S+oaqoSvDAJAJI/LDGLguZf54rdFR6O2S2a98dquycJWUt3jgt/KLgmUJNiI qlqH9At/xGdV8kQUHFYVqFgxUoo4rXBOBkE2zGYZPKbTLvLwjSk064eO2rMH+3Sdtizh 8pFq4veMZFQMyRvpuXyNi976/PppjTqfbpo8B0IiiP8p4gC+SV6bi6xjWtD4hFLILcbU B8XA== X-Gm-Message-State: AOAM530akF3P7V1GV5E6Nz0YcOIntHNVmvlswOhLLDMubrJ9wKmB2aBa bAjkUf3JWEWVAsDzXFPTPsDV7w== X-Google-Smtp-Source: ABdhPJz06+PUPTCOD5MO6YcYJfu8e1guRGyarj130cNdAlQFDKce0Oko/G5bRBr5wbl0qK0lrF7Apg== X-Received: by 2002:a37:4ccf:: with SMTP id z198mr26929935qka.348.1604498425743; Wed, 04 Nov 2020 06:00:25 -0800 (PST) Received: from ziepe.ca (hlfxns017vw-156-34-48-30.dhcp-dynamic.fibreop.ns.bellaliant.net. [156.34.48.30]) by smtp.gmail.com with ESMTPSA id y3sm131855qto.2.2020.11.04.06.00.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Nov 2020 06:00:24 -0800 (PST) Received: from jgg by mlx with local (Exim 4.94) (envelope-from ) id 1kaJKp-00GVgS-9E; Wed, 04 Nov 2020 10:00:23 -0400 Date: Wed, 4 Nov 2020 10:00:23 -0400 From: Jason Gunthorpe To: Daniel Vetter Cc: John Hubbard , DRI Development , LKML , KVM list , Linux MM , Linux ARM , linux-samsung-soc , "open list:DMA BUFFER SHARING FRAMEWORK" , Daniel Vetter , Pawel Osciak , Marek Szyprowski , Kyungmin Park , Tomasz Figa , Mauro Carvalho Chehab , Andrew Morton , =?utf-8?B?SsOpcsO0bWU=?= Glisse , Jan Kara , Dan Williams Subject: Re: [PATCH v5 05/15] mm/frame-vector: Use FOLL_LONGTERM Message-ID: <20201104140023.GQ36674@ziepe.ca> References: <20201030100815.2269-1-daniel.vetter@ffwll.ch> <20201030100815.2269-6-daniel.vetter@ffwll.ch> <446b2d5b-a1a1-a408-f884-f17a04b72c18@nvidia.com> <1f7cf690-35e2-c56f-6d3f-94400633edd2@nvidia.com> <7f29a42a-c408-525d-90b7-ef3c12b5826c@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org On Sun, Nov 01, 2020 at 11:50:39PM +0100, Daniel Vetter wrote: > It's not device drivers, but everyone else. At least my understanding > is that VM_IO | VM_PFNMAP means "even if it happens to be backed by a > struct page, do not treat it like normal memory". And gup/pup_fast > happily break that. I tried to chase the history of that test, didn't > turn up anything I understood much: VM_IO isn't suppose do thave struct pages, so how can gup_fast return them? I thought some magic in the PTE flags excluded this? Jason