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=-6.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 4EDBFC35257 for ; Fri, 2 Oct 2020 18:17:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D30C720795 for ; Fri, 2 Oct 2020 18:17:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="UroveKdE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388237AbgJBSRA (ORCPT ); Fri, 2 Oct 2020 14:17:00 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33574 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726017AbgJBSRA (ORCPT ); Fri, 2 Oct 2020 14:17:00 -0400 Received: from mail-ot1-x343.google.com (mail-ot1-x343.google.com [IPv6:2607:f8b0:4864:20::343]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EAB8EC0613E3 for ; Fri, 2 Oct 2020 11:16:59 -0700 (PDT) Received: by mail-ot1-x343.google.com with SMTP id u25so2249989otq.6 for ; Fri, 02 Oct 2020 11:16:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=3HxwxxjOyUFsHnvZd90so4n7HtMcvrp+2NDYk+teChw=; b=UroveKdEgKPvYhDgIRFBP6hGaOMHl0KhWjPmr7h+me9Xj+hsNqVEe+KzxfQ5R752mW Q39uBXtohsZOj34gGmK/hanyDQGQMTFvEwg1txwSCZatYOYvpHfVCUEfTc1tX+5qw+e4 lhr2S+yleRha4sKjZin5W1q02Y1XO7J4/uNO0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=3HxwxxjOyUFsHnvZd90so4n7HtMcvrp+2NDYk+teChw=; b=gnJ2Dpznk1pGe35I7GvPRrFAN3GAj9Yv/LZLkwLczIYLGC3VpSFpl+DorICFIo4MFS l+hSjRQzEtqMBFsqHV9ixsEt9p5ncoLxh9eit/0i0K/ZDIOGIKlBdL52behI+95eqgwf NWguIcQHTT4dQwpI20Oe7s6Z0JXi9Q54d9u1GKD6Hh3o8AzG/Lonr05zWVE19pRHkNnc O/BY2DpkesBY3sBszt5WIWmwc/K2Ie80Ni8bVRy64xQBcnrfe3pZGjT7loiE58IH7PHV szUT1IuBiAuAq0LTvQBYYMpnTCtUEU2ZLzLooexdWZs6N2lmA3VDCHj3ji9JqGOasE0B DIGA== X-Gm-Message-State: AOAM531UN2EIvYnz15qONOniuFufhGjHlebmxot78hQJdMGChooAsNCU dfljxUViPqREqaw+epu0dePksS3TtaPYhqFrTmhBww== X-Google-Smtp-Source: ABdhPJz/iLpxd0MKJvGez6uG++167T4Nd3ZEU24lIiueGBImWGdkODsxyKl+FpR0pn01MP2E0GHPOCfnbU7WfP4NbAY= X-Received: by 2002:a9d:4b99:: with SMTP id k25mr2747483otf.281.1601662619231; Fri, 02 Oct 2020 11:16:59 -0700 (PDT) MIME-Version: 1.0 References: <20201002175303.390363-1-daniel.vetter@ffwll.ch> <20201002175303.390363-2-daniel.vetter@ffwll.ch> <20201002180603.GL9916@ziepe.ca> In-Reply-To: <20201002180603.GL9916@ziepe.ca> From: Daniel Vetter Date: Fri, 2 Oct 2020 20:16:48 +0200 Message-ID: Subject: Re: [PATCH 2/2] mm/frame-vec: use FOLL_LONGTERM To: Jason Gunthorpe Cc: DRI Development , LKML , Daniel Vetter , Andrew Morton , John Hubbard , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Jan Kara , Dan Williams , Linux MM , Linux ARM , linux-samsung-soc , "open list:DMA BUFFER SHARING FRAMEWORK" Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Oct 2, 2020 at 8:06 PM Jason Gunthorpe wrote: > On Fri, Oct 02, 2020 at 07:53:03PM +0200, Daniel Vetter wrote: > > For $reasons I've stumbled over this code and I'm not sure the change > > to the new gup functions in 55a650c35fea ("mm/gup: frame_vector: > > convert get_user_pages() --> pin_user_pages()") was entirely correct. > > > > This here is used for long term buffers (not just quick I/O) like > > RDMA, and John notes this in his patch. But I thought the rule for > > these is that they need to add FOLL_LONGTERM, which John's patch > > didn't do. > > > > There is already a dax specific check (added in b7f0554a56f2 ("mm: > > fail get_vaddr_frames() for filesystem-dax mappings")), so this seems > > like the prudent thing to do. > > > > Signed-off-by: Daniel Vetter > > Cc: Andrew Morton > > Cc: John Hubbard > > Cc: J=C3=A9r=C3=B4me Glisse > > Cc: Jan Kara > > Cc: Dan Williams > > Cc: linux-mm@kvack.org > > Cc: linux-arm-kernel@lists.infradead.org > > Cc: linux-samsung-soc@vger.kernel.org > > Cc: linux-media@vger.kernel.org > > Hi all, > > > > I stumbled over this and figured typing this patch can't hurt. Really > > just to maybe learn a few things about how gup/pup is supposed to be > > used (we have a bit of that in drivers/gpu), this here isn't really > > ralated to anything I'm doing. > > FOLL_FORCE is a pretty big clue it should be FOLL_LONGTERM, IMHO Since you're here ... I've noticed that ib sets FOLL_FORCE when the ib verb access mode indicates possible writes. I'm not really clear on why FOLL_WRITE isn't enough any why you need to be able to write through a vma that's write protected currently. > > I'm also wondering whether the explicit dax check should be removed, > > since FOLL_LONGTERM should take care of that already. > > Yep! Confirms the above! > > This get_vaddr_frames() thing looks impossible to use properly. How on > earth does a driver guarentee > > "If @start belongs to VM_IO | VM_PFNMAP vma, we don't touch page > structures and the caller must make sure pfns aren't reused for > anything else while he is using them." > > The only possible way to do that is if the driver restricts the VMAs > to ones it owns and interacts with the vm_private data to refcount > something. > > Since every driver does this wrong anything that uses this is creating > terrifying security issues. > > IMHO this whole API should be deleted :( Yeah that part I just tried to conveniently ignore. I guess this dates back to a time when ioremaps where at best fixed, and there wasn't anything like a gpu driver dynamically managing vram around, resulting in random entirely unrelated things possibly being mapped to that set of pfns. The underlying follow_pfn is also used in other places within drivers/media, so this doesn't seem to be an accident, but actually intentional. I guess minimally we'd need a VM_PFNMAP flag for dynamically manged drivers like modern drm gpu drivers, to make sure follow_pfn doesn't follow these? -Daniel --=20 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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 6F38AC4363D for ; Fri, 2 Oct 2020 18:18:51 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 12ED520758 for ; Fri, 2 Oct 2020 18:18:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="XZmOUpg2"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="UroveKdE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 12ED520758 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id: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=IVMWoYUD9x4JYJdNiZhLDH7hvqaeNsooRvLOkADbblI=; b=XZmOUpg2fH+ccSyodU+l+rzIF SHojdyYi/gyZ9uonyZWpHwvHUY+uNnlGrmByNOvEw6MKoMM+zwreSN+fj5zo3blHytJpKJEJmWi88 4WjBfiR4knVy5wdJmMglu4DZWdX6mMmZ1BXNbLFQ2HJXLYRlxMbdNT6iJsKXdBSdh6dRA69v+Z35V rGTwR6jJhpAS4x6z8ws852MMXGmy3Zc7sm3PLUVcQ4kyMg+igsKbd3o151rKphhLue5IeINFajMg9 tsIpwVV3DEVCpdNTbSGqgeotkxFk2MK9Qjv5Rq2OZqepsjgEK76+zbK5nxmMpazsv4U6y+NxeWcu1 Ar4I5SNAQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kOPc8-00014m-AJ; Fri, 02 Oct 2020 18:17:04 +0000 Received: from mail-ot1-x341.google.com ([2607:f8b0:4864:20::341]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kOPc5-00013f-JX for linux-arm-kernel@lists.infradead.org; Fri, 02 Oct 2020 18:17:02 +0000 Received: by mail-ot1-x341.google.com with SMTP id c2so2255542otp.7 for ; Fri, 02 Oct 2020 11:17:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=3HxwxxjOyUFsHnvZd90so4n7HtMcvrp+2NDYk+teChw=; b=UroveKdEgKPvYhDgIRFBP6hGaOMHl0KhWjPmr7h+me9Xj+hsNqVEe+KzxfQ5R752mW Q39uBXtohsZOj34gGmK/hanyDQGQMTFvEwg1txwSCZatYOYvpHfVCUEfTc1tX+5qw+e4 lhr2S+yleRha4sKjZin5W1q02Y1XO7J4/uNO0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=3HxwxxjOyUFsHnvZd90so4n7HtMcvrp+2NDYk+teChw=; b=O4Z3LTiBOa4nyn0TVhZtAadWPyIFuAeV8pkl7JiaIejpgA6UjKmB7EbizhBeMeh2pW +v28RJfhLe2eMbxNmfAM212SaVIR0OUhOLhb82cIPhxwt0+GTdrtER4ed23SCf2Nnx0S 7BKzrzdxUvkTskMpReif/s+GxgQ/GImsVy7J6IGilTl/q3Rfo8FFvBrEHohycoGXu7iW Dn3OZsFRu4iQfAA0MQJ7sq86gZm3kVq6lpR7EkzZSaKVMLClnWk7tJ0wXvhUAYTC+Y9X VdShsvzNGR8P/CcmX8+Zo3YtoT19YFzmXR8xE+yH45xuXwTkwTb4bDEnXIs8H9IAgGrB 6p3A== X-Gm-Message-State: AOAM5318Sl/+SGIIc0TLrMkR5sIyT/M7XjvzzZbkGSHGTlrfYAiB8szQ iA6DTgfxVUITs44KXSYUq1dzM62L2KWP/Z9D/wrB0Q== X-Google-Smtp-Source: ABdhPJz/iLpxd0MKJvGez6uG++167T4Nd3ZEU24lIiueGBImWGdkODsxyKl+FpR0pn01MP2E0GHPOCfnbU7WfP4NbAY= X-Received: by 2002:a9d:4b99:: with SMTP id k25mr2747483otf.281.1601662619231; Fri, 02 Oct 2020 11:16:59 -0700 (PDT) MIME-Version: 1.0 References: <20201002175303.390363-1-daniel.vetter@ffwll.ch> <20201002175303.390363-2-daniel.vetter@ffwll.ch> <20201002180603.GL9916@ziepe.ca> In-Reply-To: <20201002180603.GL9916@ziepe.ca> From: Daniel Vetter Date: Fri, 2 Oct 2020 20:16:48 +0200 Message-ID: Subject: Re: [PATCH 2/2] mm/frame-vec: use FOLL_LONGTERM To: Jason Gunthorpe X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201002_141701_657808_BD37DF3A X-CRM114-Status: GOOD ( 30.99 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-samsung-soc , Jan Kara , John Hubbard , LKML , DRI Development , Linux MM , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Daniel Vetter , Andrew Morton , Dan Williams , Linux ARM , "open list:DMA BUFFER SHARING FRAMEWORK" Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org T24gRnJpLCBPY3QgMiwgMjAyMCBhdCA4OjA2IFBNIEphc29uIEd1bnRob3JwZSA8amdnQHppZXBl LmNhPiB3cm90ZToKPiBPbiBGcmksIE9jdCAwMiwgMjAyMCBhdCAwNzo1MzowM1BNICswMjAwLCBE YW5pZWwgVmV0dGVyIHdyb3RlOgo+ID4gRm9yICRyZWFzb25zIEkndmUgc3R1bWJsZWQgb3ZlciB0 aGlzIGNvZGUgYW5kIEknbSBub3Qgc3VyZSB0aGUgY2hhbmdlCj4gPiB0byB0aGUgbmV3IGd1cCBm dW5jdGlvbnMgaW4gNTVhNjUwYzM1ZmVhICgibW0vZ3VwOiBmcmFtZV92ZWN0b3I6Cj4gPiBjb252 ZXJ0IGdldF91c2VyX3BhZ2VzKCkgLS0+IHBpbl91c2VyX3BhZ2VzKCkiKSB3YXMgZW50aXJlbHkg Y29ycmVjdC4KPiA+Cj4gPiBUaGlzIGhlcmUgaXMgdXNlZCBmb3IgbG9uZyB0ZXJtIGJ1ZmZlcnMg KG5vdCBqdXN0IHF1aWNrIEkvTykgbGlrZQo+ID4gUkRNQSwgYW5kIEpvaG4gbm90ZXMgdGhpcyBp biBoaXMgcGF0Y2guIEJ1dCBJIHRob3VnaHQgdGhlIHJ1bGUgZm9yCj4gPiB0aGVzZSBpcyB0aGF0 IHRoZXkgbmVlZCB0byBhZGQgRk9MTF9MT05HVEVSTSwgd2hpY2ggSm9obidzIHBhdGNoCj4gPiBk aWRuJ3QgZG8uCj4gPgo+ID4gVGhlcmUgaXMgYWxyZWFkeSBhIGRheCBzcGVjaWZpYyBjaGVjayAo YWRkZWQgaW4gYjdmMDU1NGE1NmYyICgibW06Cj4gPiBmYWlsIGdldF92YWRkcl9mcmFtZXMoKSBm b3IgZmlsZXN5c3RlbS1kYXggbWFwcGluZ3MiKSksIHNvIHRoaXMgc2VlbXMKPiA+IGxpa2UgdGhl IHBydWRlbnQgdGhpbmcgdG8gZG8uCj4gPgo+ID4gU2lnbmVkLW9mZi1ieTogRGFuaWVsIFZldHRl ciA8ZGFuaWVsLnZldHRlckBpbnRlbC5jb20+Cj4gPiBDYzogQW5kcmV3IE1vcnRvbiA8YWtwbUBs aW51eC1mb3VuZGF0aW9uLm9yZz4KPiA+IENjOiBKb2huIEh1YmJhcmQgPGpodWJiYXJkQG52aWRp YS5jb20+Cj4gPiBDYzogSsOpcsO0bWUgR2xpc3NlIDxqZ2xpc3NlQHJlZGhhdC5jb20+Cj4gPiBD YzogSmFuIEthcmEgPGphY2tAc3VzZS5jej4KPiA+IENjOiBEYW4gV2lsbGlhbXMgPGRhbi5qLndp bGxpYW1zQGludGVsLmNvbT4KPiA+IENjOiBsaW51eC1tbUBrdmFjay5vcmcKPiA+IENjOiBsaW51 eC1hcm0ta2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmcKPiA+IENjOiBsaW51eC1zYW1zdW5nLXNv Y0B2Z2VyLmtlcm5lbC5vcmcKPiA+IENjOiBsaW51eC1tZWRpYUB2Z2VyLmtlcm5lbC5vcmcKPiA+ IEhpIGFsbCwKPiA+Cj4gPiBJIHN0dW1ibGVkIG92ZXIgdGhpcyBhbmQgZmlndXJlZCB0eXBpbmcg dGhpcyBwYXRjaCBjYW4ndCBodXJ0LiBSZWFsbHkKPiA+IGp1c3QgdG8gbWF5YmUgbGVhcm4gYSBm ZXcgdGhpbmdzIGFib3V0IGhvdyBndXAvcHVwIGlzIHN1cHBvc2VkIHRvIGJlCj4gPiB1c2VkICh3 ZSBoYXZlIGEgYml0IG9mIHRoYXQgaW4gZHJpdmVycy9ncHUpLCB0aGlzIGhlcmUgaXNuJ3QgcmVh bGx5Cj4gPiByYWxhdGVkIHRvIGFueXRoaW5nIEknbSBkb2luZy4KPgo+IEZPTExfRk9SQ0UgaXMg YSBwcmV0dHkgYmlnIGNsdWUgaXQgc2hvdWxkIGJlIEZPTExfTE9OR1RFUk0sIElNSE8KClNpbmNl IHlvdSdyZSBoZXJlIC4uLiBJJ3ZlIG5vdGljZWQgdGhhdCBpYiBzZXRzIEZPTExfRk9SQ0Ugd2hl biB0aGUgaWIKdmVyYiBhY2Nlc3MgbW9kZSBpbmRpY2F0ZXMgcG9zc2libGUgd3JpdGVzLiBJJ20g bm90IHJlYWxseSBjbGVhciBvbgp3aHkgRk9MTF9XUklURSBpc24ndCBlbm91Z2ggYW55IHdoeSB5 b3UgbmVlZCB0byBiZSBhYmxlIHRvIHdyaXRlCnRocm91Z2ggYSB2bWEgdGhhdCdzIHdyaXRlIHBy b3RlY3RlZCBjdXJyZW50bHkuCgo+ID4gSSdtIGFsc28gd29uZGVyaW5nIHdoZXRoZXIgdGhlIGV4 cGxpY2l0IGRheCBjaGVjayBzaG91bGQgYmUgcmVtb3ZlZCwKPiA+IHNpbmNlIEZPTExfTE9OR1RF Uk0gc2hvdWxkIHRha2UgY2FyZSBvZiB0aGF0IGFscmVhZHkuCj4KPiBZZXAhIENvbmZpcm1zIHRo ZSBhYm92ZSEKPgo+IFRoaXMgZ2V0X3ZhZGRyX2ZyYW1lcygpIHRoaW5nIGxvb2tzIGltcG9zc2li bGUgdG8gdXNlIHByb3Blcmx5LiBIb3cgb24KPiBlYXJ0aCBkb2VzIGEgZHJpdmVyIGd1YXJlbnRl ZQo+Cj4gICJJZiBAc3RhcnQgYmVsb25ncyB0byBWTV9JTyB8IFZNX1BGTk1BUCB2bWEsIHdlIGRv bid0IHRvdWNoIHBhZ2UKPiAgc3RydWN0dXJlcyBhbmQgdGhlIGNhbGxlciBtdXN0IG1ha2Ugc3Vy ZSBwZm5zIGFyZW4ndCByZXVzZWQgZm9yCj4gIGFueXRoaW5nIGVsc2Ugd2hpbGUgaGUgaXMgdXNp bmcgdGhlbS4iCj4KPiBUaGUgb25seSBwb3NzaWJsZSB3YXkgdG8gZG8gdGhhdCBpcyBpZiB0aGUg ZHJpdmVyIHJlc3RyaWN0cyB0aGUgVk1Bcwo+IHRvIG9uZXMgaXQgb3ducyBhbmQgaW50ZXJhY3Rz IHdpdGggdGhlIHZtX3ByaXZhdGUgZGF0YSB0byByZWZjb3VudAo+IHNvbWV0aGluZy4KPgo+IFNp bmNlIGV2ZXJ5IGRyaXZlciBkb2VzIHRoaXMgd3JvbmcgYW55dGhpbmcgdGhhdCB1c2VzIHRoaXMg aXMgY3JlYXRpbmcKPiB0ZXJyaWZ5aW5nIHNlY3VyaXR5IGlzc3Vlcy4KPgo+IElNSE8gdGhpcyB3 aG9sZSBBUEkgc2hvdWxkIGJlIGRlbGV0ZWQgOigKClllYWggdGhhdCBwYXJ0IEkganVzdCB0cmll ZCB0byBjb252ZW5pZW50bHkgaWdub3JlLiBJIGd1ZXNzIHRoaXMgZGF0ZXMKYmFjayB0byBhIHRp bWUgd2hlbiBpb3JlbWFwcyB3aGVyZSBhdCBiZXN0IGZpeGVkLCBhbmQgdGhlcmUgd2Fzbid0CmFu eXRoaW5nIGxpa2UgYSBncHUgZHJpdmVyIGR5bmFtaWNhbGx5IG1hbmFnaW5nIHZyYW0gYXJvdW5k LCByZXN1bHRpbmcKaW4gcmFuZG9tIGVudGlyZWx5IHVucmVsYXRlZCB0aGluZ3MgcG9zc2libHkg YmVpbmcgbWFwcGVkIHRvIHRoYXQgc2V0Cm9mIHBmbnMuCgpUaGUgdW5kZXJseWluZyBmb2xsb3df cGZuIGlzIGFsc28gdXNlZCBpbiBvdGhlciBwbGFjZXMgd2l0aGluCmRyaXZlcnMvbWVkaWEsIHNv IHRoaXMgZG9lc24ndCBzZWVtIHRvIGJlIGFuIGFjY2lkZW50LCBidXQgYWN0dWFsbHkKaW50ZW50 aW9uYWwuCgpJIGd1ZXNzIG1pbmltYWxseSB3ZSdkIG5lZWQgYSBWTV9QRk5NQVAgZmxhZyBmb3Ig ZHluYW1pY2FsbHkgbWFuZ2VkCmRyaXZlcnMgbGlrZSBtb2Rlcm4gZHJtIGdwdSBkcml2ZXJzLCB0 byBtYWtlIHN1cmUgZm9sbG93X3BmbiBkb2Vzbid0CmZvbGxvdyB0aGVzZT8KLURhbmllbAotLSAK RGFuaWVsIFZldHRlcgpTb2Z0d2FyZSBFbmdpbmVlciwgSW50ZWwgQ29ycG9yYXRpb24KaHR0cDov L2Jsb2cuZmZ3bGwuY2gKCl9fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fCmxpbnV4LWFybS1rZXJuZWwgbWFpbGluZyBsaXN0CmxpbnV4LWFybS1rZXJuZWxAbGlz dHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9tYWlsbWFuL2xpc3Rp bmZvL2xpbnV4LWFybS1rZXJuZWwK 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=-6.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 0F79EC4363D for ; Fri, 2 Oct 2020 18:17:02 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 6741920758 for ; Fri, 2 Oct 2020 18:17:01 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=ffwll.ch header.i=@ffwll.ch header.b="UroveKdE" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6741920758 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=dri-devel-bounces@lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 53F296E9BB; Fri, 2 Oct 2020 18:17:00 +0000 (UTC) Received: from mail-ot1-x342.google.com (mail-ot1-x342.google.com [IPv6:2607:f8b0:4864:20::342]) by gabe.freedesktop.org (Postfix) with ESMTPS id E3EFC6E9BB for ; Fri, 2 Oct 2020 18:16:59 +0000 (UTC) Received: by mail-ot1-x342.google.com with SMTP id s66so2262260otb.2 for ; Fri, 02 Oct 2020 11:16:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=3HxwxxjOyUFsHnvZd90so4n7HtMcvrp+2NDYk+teChw=; b=UroveKdEgKPvYhDgIRFBP6hGaOMHl0KhWjPmr7h+me9Xj+hsNqVEe+KzxfQ5R752mW Q39uBXtohsZOj34gGmK/hanyDQGQMTFvEwg1txwSCZatYOYvpHfVCUEfTc1tX+5qw+e4 lhr2S+yleRha4sKjZin5W1q02Y1XO7J4/uNO0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=3HxwxxjOyUFsHnvZd90so4n7HtMcvrp+2NDYk+teChw=; b=sw+jsZqnbacsEDIri4HbtQgvMkRlX2hsnOjOj2QsrZnlY12qVyulwuNd08dyYIoe4J eigGfZwAmMKRZ75p3tSVuJG4vkxc1zSpntaw4cK4PF+j3Oibc3ZzWmxi77TGDrdO7HV3 nvaYzFEP+/j5KLZ03WN44xJpVXr23wm2hBF2FdL87IjPbT71i49ktAxs2GBvMsfdQImh N5KKoZTU7NVQciKXWd0KpZRaKBMMXRc+iyQ/sX23TU2Pk/xlMqa5iEJ9r6QN+wb+u0a+ +HcCBmpyk75g39oQcxJCNkOV3TSahCKF4uh/7dpvmetcFom50Q1qKYFFXDuoKnJEZvbr 6E4w== X-Gm-Message-State: AOAM532BTPAzROZyNBLOd1EhBL5LKZeEi+dVzDX70sHzS8QqnipTL5+u Pnvr1vCOWd8j56CJ8bLNw+xD3v5+r31eIBBSsModjw== X-Google-Smtp-Source: ABdhPJz/iLpxd0MKJvGez6uG++167T4Nd3ZEU24lIiueGBImWGdkODsxyKl+FpR0pn01MP2E0GHPOCfnbU7WfP4NbAY= X-Received: by 2002:a9d:4b99:: with SMTP id k25mr2747483otf.281.1601662619231; Fri, 02 Oct 2020 11:16:59 -0700 (PDT) MIME-Version: 1.0 References: <20201002175303.390363-1-daniel.vetter@ffwll.ch> <20201002175303.390363-2-daniel.vetter@ffwll.ch> <20201002180603.GL9916@ziepe.ca> In-Reply-To: <20201002180603.GL9916@ziepe.ca> From: Daniel Vetter Date: Fri, 2 Oct 2020 20:16:48 +0200 Message-ID: Subject: Re: [PATCH 2/2] mm/frame-vec: use FOLL_LONGTERM To: Jason Gunthorpe 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-samsung-soc , Jan Kara , John Hubbard , LKML , DRI Development , Linux MM , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Daniel Vetter , Andrew Morton , Dan Williams , Linux ARM , "open list:DMA BUFFER SHARING FRAMEWORK" Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" T24gRnJpLCBPY3QgMiwgMjAyMCBhdCA4OjA2IFBNIEphc29uIEd1bnRob3JwZSA8amdnQHppZXBl LmNhPiB3cm90ZToKPiBPbiBGcmksIE9jdCAwMiwgMjAyMCBhdCAwNzo1MzowM1BNICswMjAwLCBE YW5pZWwgVmV0dGVyIHdyb3RlOgo+ID4gRm9yICRyZWFzb25zIEkndmUgc3R1bWJsZWQgb3ZlciB0 aGlzIGNvZGUgYW5kIEknbSBub3Qgc3VyZSB0aGUgY2hhbmdlCj4gPiB0byB0aGUgbmV3IGd1cCBm dW5jdGlvbnMgaW4gNTVhNjUwYzM1ZmVhICgibW0vZ3VwOiBmcmFtZV92ZWN0b3I6Cj4gPiBjb252 ZXJ0IGdldF91c2VyX3BhZ2VzKCkgLS0+IHBpbl91c2VyX3BhZ2VzKCkiKSB3YXMgZW50aXJlbHkg Y29ycmVjdC4KPiA+Cj4gPiBUaGlzIGhlcmUgaXMgdXNlZCBmb3IgbG9uZyB0ZXJtIGJ1ZmZlcnMg KG5vdCBqdXN0IHF1aWNrIEkvTykgbGlrZQo+ID4gUkRNQSwgYW5kIEpvaG4gbm90ZXMgdGhpcyBp biBoaXMgcGF0Y2guIEJ1dCBJIHRob3VnaHQgdGhlIHJ1bGUgZm9yCj4gPiB0aGVzZSBpcyB0aGF0 IHRoZXkgbmVlZCB0byBhZGQgRk9MTF9MT05HVEVSTSwgd2hpY2ggSm9obidzIHBhdGNoCj4gPiBk aWRuJ3QgZG8uCj4gPgo+ID4gVGhlcmUgaXMgYWxyZWFkeSBhIGRheCBzcGVjaWZpYyBjaGVjayAo YWRkZWQgaW4gYjdmMDU1NGE1NmYyICgibW06Cj4gPiBmYWlsIGdldF92YWRkcl9mcmFtZXMoKSBm b3IgZmlsZXN5c3RlbS1kYXggbWFwcGluZ3MiKSksIHNvIHRoaXMgc2VlbXMKPiA+IGxpa2UgdGhl IHBydWRlbnQgdGhpbmcgdG8gZG8uCj4gPgo+ID4gU2lnbmVkLW9mZi1ieTogRGFuaWVsIFZldHRl ciA8ZGFuaWVsLnZldHRlckBpbnRlbC5jb20+Cj4gPiBDYzogQW5kcmV3IE1vcnRvbiA8YWtwbUBs aW51eC1mb3VuZGF0aW9uLm9yZz4KPiA+IENjOiBKb2huIEh1YmJhcmQgPGpodWJiYXJkQG52aWRp YS5jb20+Cj4gPiBDYzogSsOpcsO0bWUgR2xpc3NlIDxqZ2xpc3NlQHJlZGhhdC5jb20+Cj4gPiBD YzogSmFuIEthcmEgPGphY2tAc3VzZS5jej4KPiA+IENjOiBEYW4gV2lsbGlhbXMgPGRhbi5qLndp bGxpYW1zQGludGVsLmNvbT4KPiA+IENjOiBsaW51eC1tbUBrdmFjay5vcmcKPiA+IENjOiBsaW51 eC1hcm0ta2VybmVsQGxpc3RzLmluZnJhZGVhZC5vcmcKPiA+IENjOiBsaW51eC1zYW1zdW5nLXNv Y0B2Z2VyLmtlcm5lbC5vcmcKPiA+IENjOiBsaW51eC1tZWRpYUB2Z2VyLmtlcm5lbC5vcmcKPiA+ IEhpIGFsbCwKPiA+Cj4gPiBJIHN0dW1ibGVkIG92ZXIgdGhpcyBhbmQgZmlndXJlZCB0eXBpbmcg dGhpcyBwYXRjaCBjYW4ndCBodXJ0LiBSZWFsbHkKPiA+IGp1c3QgdG8gbWF5YmUgbGVhcm4gYSBm ZXcgdGhpbmdzIGFib3V0IGhvdyBndXAvcHVwIGlzIHN1cHBvc2VkIHRvIGJlCj4gPiB1c2VkICh3 ZSBoYXZlIGEgYml0IG9mIHRoYXQgaW4gZHJpdmVycy9ncHUpLCB0aGlzIGhlcmUgaXNuJ3QgcmVh bGx5Cj4gPiByYWxhdGVkIHRvIGFueXRoaW5nIEknbSBkb2luZy4KPgo+IEZPTExfRk9SQ0UgaXMg YSBwcmV0dHkgYmlnIGNsdWUgaXQgc2hvdWxkIGJlIEZPTExfTE9OR1RFUk0sIElNSE8KClNpbmNl IHlvdSdyZSBoZXJlIC4uLiBJJ3ZlIG5vdGljZWQgdGhhdCBpYiBzZXRzIEZPTExfRk9SQ0Ugd2hl biB0aGUgaWIKdmVyYiBhY2Nlc3MgbW9kZSBpbmRpY2F0ZXMgcG9zc2libGUgd3JpdGVzLiBJJ20g bm90IHJlYWxseSBjbGVhciBvbgp3aHkgRk9MTF9XUklURSBpc24ndCBlbm91Z2ggYW55IHdoeSB5 b3UgbmVlZCB0byBiZSBhYmxlIHRvIHdyaXRlCnRocm91Z2ggYSB2bWEgdGhhdCdzIHdyaXRlIHBy b3RlY3RlZCBjdXJyZW50bHkuCgo+ID4gSSdtIGFsc28gd29uZGVyaW5nIHdoZXRoZXIgdGhlIGV4 cGxpY2l0IGRheCBjaGVjayBzaG91bGQgYmUgcmVtb3ZlZCwKPiA+IHNpbmNlIEZPTExfTE9OR1RF Uk0gc2hvdWxkIHRha2UgY2FyZSBvZiB0aGF0IGFscmVhZHkuCj4KPiBZZXAhIENvbmZpcm1zIHRo ZSBhYm92ZSEKPgo+IFRoaXMgZ2V0X3ZhZGRyX2ZyYW1lcygpIHRoaW5nIGxvb2tzIGltcG9zc2li bGUgdG8gdXNlIHByb3Blcmx5LiBIb3cgb24KPiBlYXJ0aCBkb2VzIGEgZHJpdmVyIGd1YXJlbnRl ZQo+Cj4gICJJZiBAc3RhcnQgYmVsb25ncyB0byBWTV9JTyB8IFZNX1BGTk1BUCB2bWEsIHdlIGRv bid0IHRvdWNoIHBhZ2UKPiAgc3RydWN0dXJlcyBhbmQgdGhlIGNhbGxlciBtdXN0IG1ha2Ugc3Vy ZSBwZm5zIGFyZW4ndCByZXVzZWQgZm9yCj4gIGFueXRoaW5nIGVsc2Ugd2hpbGUgaGUgaXMgdXNp bmcgdGhlbS4iCj4KPiBUaGUgb25seSBwb3NzaWJsZSB3YXkgdG8gZG8gdGhhdCBpcyBpZiB0aGUg ZHJpdmVyIHJlc3RyaWN0cyB0aGUgVk1Bcwo+IHRvIG9uZXMgaXQgb3ducyBhbmQgaW50ZXJhY3Rz IHdpdGggdGhlIHZtX3ByaXZhdGUgZGF0YSB0byByZWZjb3VudAo+IHNvbWV0aGluZy4KPgo+IFNp bmNlIGV2ZXJ5IGRyaXZlciBkb2VzIHRoaXMgd3JvbmcgYW55dGhpbmcgdGhhdCB1c2VzIHRoaXMg aXMgY3JlYXRpbmcKPiB0ZXJyaWZ5aW5nIHNlY3VyaXR5IGlzc3Vlcy4KPgo+IElNSE8gdGhpcyB3 aG9sZSBBUEkgc2hvdWxkIGJlIGRlbGV0ZWQgOigKClllYWggdGhhdCBwYXJ0IEkganVzdCB0cmll ZCB0byBjb252ZW5pZW50bHkgaWdub3JlLiBJIGd1ZXNzIHRoaXMgZGF0ZXMKYmFjayB0byBhIHRp bWUgd2hlbiBpb3JlbWFwcyB3aGVyZSBhdCBiZXN0IGZpeGVkLCBhbmQgdGhlcmUgd2Fzbid0CmFu eXRoaW5nIGxpa2UgYSBncHUgZHJpdmVyIGR5bmFtaWNhbGx5IG1hbmFnaW5nIHZyYW0gYXJvdW5k LCByZXN1bHRpbmcKaW4gcmFuZG9tIGVudGlyZWx5IHVucmVsYXRlZCB0aGluZ3MgcG9zc2libHkg YmVpbmcgbWFwcGVkIHRvIHRoYXQgc2V0Cm9mIHBmbnMuCgpUaGUgdW5kZXJseWluZyBmb2xsb3df cGZuIGlzIGFsc28gdXNlZCBpbiBvdGhlciBwbGFjZXMgd2l0aGluCmRyaXZlcnMvbWVkaWEsIHNv IHRoaXMgZG9lc24ndCBzZWVtIHRvIGJlIGFuIGFjY2lkZW50LCBidXQgYWN0dWFsbHkKaW50ZW50 aW9uYWwuCgpJIGd1ZXNzIG1pbmltYWxseSB3ZSdkIG5lZWQgYSBWTV9QRk5NQVAgZmxhZyBmb3Ig ZHluYW1pY2FsbHkgbWFuZ2VkCmRyaXZlcnMgbGlrZSBtb2Rlcm4gZHJtIGdwdSBkcml2ZXJzLCB0 byBtYWtlIHN1cmUgZm9sbG93X3BmbiBkb2Vzbid0CmZvbGxvdyB0aGVzZT8KLURhbmllbAotLSAK RGFuaWVsIFZldHRlcgpTb2Z0d2FyZSBFbmdpbmVlciwgSW50ZWwgQ29ycG9yYXRpb24KaHR0cDov L2Jsb2cuZmZ3bGwuY2gKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX18KZHJpLWRldmVsIG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Au b3JnCmh0dHBzOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRl dmVsCg==