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=unavailable 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 82E46C433B4 for ; Mon, 17 May 2021 16:34:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66305610E9 for ; Mon, 17 May 2021 16:34:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235388AbhEQQfp (ORCPT ); Mon, 17 May 2021 12:35:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245182AbhEQQfd (ORCPT ); Mon, 17 May 2021 12:35:33 -0400 Received: from mail-ot1-x333.google.com (mail-ot1-x333.google.com [IPv6:2607:f8b0:4864:20::333]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 928C5C0610FB for ; Mon, 17 May 2021 08:29:47 -0700 (PDT) Received: by mail-ot1-x333.google.com with SMTP id t10-20020a05683022eab0290304ed8bc759so5855721otc.12 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=tftXcm6Z3aOwbxDdfBM6hgKVYjnnlkZNvfDst0ixLpUo9rWe3aJPxOpW7bcV0ogXXc hMAUa1luTSeecksdDeJXrsq60abnxMQMXt35LGA1Lxx6Q2u9IUdmUwTYZvFDOSFvNjV+ 6LUkongzuxBgcJWEmkgqScdXf7/ijr/VOUK9D4kApiRm0iaiQQQ3NrByoU7XY0mCxBHP GZfxJIIRSzXLthCzJSfp6GybmvycBfE8jidoh8MdzM4y0rRxlYlBCc2eBj4pHwbmir7Y 4XE8nsihm8WB0Myr/TOPIEll85GYOulTQkhacg5b4VPgvXRfAu3kIoQB0rF4tFYoviwY 1fQQ== X-Gm-Message-State: AOAM530jzSu1UpbhE4wn1ezS0BfpBfQeryQwTOvTPe0+PjuErYlAAdLw GMsvyXTAiwmuYhHFnlYJ0c0yZGcACX22dbiMoYC3JA== 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" Precedence: bulk List-ID: X-Mailing-List: linux-samsung-soc@vger.kernel.org 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