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=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 17CC3C43470 for ; Mon, 17 May 2021 15:29:50 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 95C4A60720 for ; Mon, 17 May 2021 15:29:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 95C4A60720 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ffwll.ch Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 379886B0073; Mon, 17 May 2021 11:29:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 352116B0074; Mon, 17 May 2021 11:29:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1A3356B0075; Mon, 17 May 2021 11:29:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0101.hostedemail.com [216.40.44.101]) by kanga.kvack.org (Postfix) with ESMTP id DD5EB6B0073 for ; Mon, 17 May 2021 11:29:48 -0400 (EDT) Received: from smtpin08.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 816C0998E for ; Mon, 17 May 2021 15:29:48 +0000 (UTC) X-FDA: 78151108056.08.CD6B003 Received: from mail-ot1-f51.google.com (mail-ot1-f51.google.com [209.85.210.51]) by imf07.hostedemail.com (Postfix) with ESMTP id 37853A00039E for ; Mon, 17 May 2021 15:29:46 +0000 (UTC) Received: by mail-ot1-f51.google.com with SMTP id q7-20020a9d57870000b02902a5c2bd8c17so5881265oth.5 for ; Mon, 17 May 2021 08:29:47 -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; bh=LHuA8eHjuppTIJ75R7cv3VweFNbwB4dqcEtg7HA60qg=; b=RMks6CV9lAVCFBcqyvaL15OwQDYYydA46ie8ERZRUW9bdz6Ss2d63nvntdd2ppylbj TT1hoAtcrCR7P1QUgAoKu41mbQqWIXoRN7jJxyGntT0uCWz/IiczJZV24UwIWC7mZW89 iDl7tmzK3OcYBBXrYUDYJ/OJrz6o9/5h4ij88= 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; bh=LHuA8eHjuppTIJ75R7cv3VweFNbwB4dqcEtg7HA60qg=; b=p67BZhDZSbVXKMi2hiWn/bm4zO3ycpLJpZIVSq+xysaFWHF4xqPx9auEZY7UDugLL9 R6Yg/fgCiwvisbZr5nDxfC0bRyTP34HiD1NbKXhFtIAXotG+QniNzxuT14JM2WI63xbk NdB8Us/0WfADrQ/fJi0Q1CRkqSvw8qZcPRgVwEC+BxuH4DmU1JQ2BKrBEOv1qKsU3eLP QEAS56HnaR3hvrIsDMzwdG++haOzjF0HtnY80h++P9S5wMBxxxw2cc42JxSlVO1guBXW S1xADoUiC+JSAzllON3xbbHI6xuInBjAA8QVT2bwZZtXht58Ut9lq8zEGuxTF1ekQPX1 VJLQ== X-Gm-Message-State: AOAM533nHt+pF5qreot+jcJF0frRTSW67KTRDpr1TJYC9Pk2Tq+3oc4d 2Nhv1nRMroqpTffsme1HvNnwGYe1BTQ5PClFJr+GAw== X-Google-Smtp-Source: ABdhPJyx4VgXyr7sHxhLzHJfU08wfDCFYrZOk1+l9hfQuvBlJV+AtL3GicGrv7/C44z5A3YFPk7MxSeP6Ot3b+xUVts= X-Received: by 2002:a05:6830:1155:: with SMTP id x21mr88425otq.303.1621265387064; Mon, 17 May 2021 08:29:47 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Daniel Vetter Date: Mon, 17 May 2021 17:29:35 +0200 Message-ID: Subject: Re: [PULL] topic/iomem-mmap-vs-gup To: Christoph Hellwig , Stephen Rothwell Cc: Linus Torvalds , Tomasz Figa , Marek Szyprowski , Mauro Carvalho Chehab , DRI Development , LKML , Linux-MM , Linux ARM , Linux Media Mailing List , linux-samsung-soc Content-Type: text/plain; charset="UTF-8" Authentication-Results: imf07.hostedemail.com; dkim=pass header.d=ffwll.ch header.s=google header.b=RMks6CV9; dmarc=none; spf=none (imf07.hostedemail.com: domain of daniel.vetter@ffwll.ch has no SPF policy when checking 209.85.210.51) smtp.mailfrom=daniel.vetter@ffwll.ch X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 37853A00039E X-Stat-Signature: cftg6hzino8s9hsitgigfznb6kefwsqf X-HE-Tag: 1621265386-860280 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, May 10, 2021 at 9:30 AM Christoph Hellwig wrote: > > On Mon, May 10, 2021 at 09:16:58AM +0200, Daniel Vetter wrote: > > > End result: not pulling it, unless somebody can explain to me in small > > > words why I'm wrong and have the mental capacity of a damaged rodent. > > > > No rodents I think, just more backstory of how this all fits. tldr; > > pin_user_pages is the only safe use of this vb2 userptr thing. > > Yes, which is why I advocate for just ripping the follow_pfn path > out entirely. It could have been used for crazy ad dangerous peer to > peer transfers outside of any infrastructure making it safe, or for > pre-CMA kernel memory carveouts for lage contiguous memory allocations > (which are pretty broken by design as well). So IMHO the only sensible > thing is to remove this cruft entirely, and if it breaks a currently > working setup (which I think is unlikely) we'll have to make sure it > can work the proper way. Since I'm not getting any cozy consenus vibes here on any option I think I'll just drop this. Stephen, can you pls drop git://anongit.freedesktop.org/drm/drm topic/iomem-mmap-vs-gup from linux-next? It's not going anywhere. I'll also go ahead and delete the branch, to make sure you catch this update :-) Thanks, Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch