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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 2EA99C3A59D for ; Fri, 16 Aug 2019 16:31:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 06AC02171F for ; Fri, 16 Aug 2019 16:31:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=ziepe.ca header.i=@ziepe.ca header.b="I8NWKYwa" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727300AbfHPQbX (ORCPT ); Fri, 16 Aug 2019 12:31:23 -0400 Received: from mail-qt1-f195.google.com ([209.85.160.195]:42459 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726447AbfHPQbW (ORCPT ); Fri, 16 Aug 2019 12:31:22 -0400 Received: by mail-qt1-f195.google.com with SMTP id t12so6688655qtp.9 for ; Fri, 16 Aug 2019 09:31:22 -0700 (PDT) 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:user-agent; bh=Q07PDQQFTsBG0+IljaPmiFmWlKr48/NTXtftkV/guY4=; b=I8NWKYwa4+LMYIEL3v6vTz8y0vEwzbwwf2hFe9gwajh+1WXmOIgwGm77LQD0FK550N YmOgkBjEo+LxcVe3peySHrZqigyvY2ximEDABzQ24c1Y/aeMeENxU8q1MpRNsx2C0Yv2 P6CSLX3qtWaTwMmlTJL7KqJuknLioR6OoiPRfqOUzT18MBUSa+JPVZhYJjZ5IkxM+Lpz IZPRCrp30aBEarURJEXC86jWyfx6cw5XV1zVfBpopUAIovi8AWgC/U7SbaB+i16OrJ3p glzrqXekDG7gZ9V2khdjtXapxYuhmKY9k6i12vc/eo2Vl+/8TFgLmknlVdSqNNh+ddMB VBiw== 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:user-agent; bh=Q07PDQQFTsBG0+IljaPmiFmWlKr48/NTXtftkV/guY4=; b=FGXfpknCTcutfOpZB3K7Koeah2Ms9rNrGE4R0neYD30qWeb1TDaOX/QjeFHEd3B7VT j8siakTkJnlf0jATFVvjnEfB9IsKxJBwOIgntuqZ7B2xZ2kBXdOpkymjJ77mV5JVYOIV uWanwhO+gxi6XA7zsMKyq546ylbil4Az7JTjTEGn77Sl3mNITmTIBbOLA+QRmt5LRgEq HdsbaWegEcMdSsdedILADr5J5/Y7KkHgrG9Nf841sugaHD45Wq8FaAEotv39Q1yi0Twd wU2YZYPLLZ9FKRbjBnBqnV2TOcVTW9T+bde8kmhMdMUjSRrEl1tyI+/qOSlzh2YpOVjG J+og== X-Gm-Message-State: APjAAAX6dkBLqJ62WFM1R3XIDNqQgOu/1dy3KoAuSKpvouEEHXxow4at DuaVSXxdINrriJqPeygOnokUCnvIadQ= X-Google-Smtp-Source: APXvYqyOu4QUIxVU7pL68pfhAnBIR85+JknyfuXMsLG/1jKGE4MxqYbqiE8sQom1Us1Ccd0ZveLEZw== X-Received: by 2002:aed:3e6f:: with SMTP id m44mr9484086qtf.220.1565973081751; Fri, 16 Aug 2019 09:31:21 -0700 (PDT) Received: from ziepe.ca (hlfxns017vw-156-34-55-100.dhcp-dynamic.fibreop.ns.bellaliant.net. [156.34.55.100]) by smtp.gmail.com with ESMTPSA id m10sm2903557qka.43.2019.08.16.09.31.21 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Fri, 16 Aug 2019 09:31:21 -0700 (PDT) Received: from jgg by mlx.ziepe.ca with local (Exim 4.90_1) (envelope-from ) id 1hyf8K-0007ns-SK; Fri, 16 Aug 2019 13:31:20 -0300 Date: Fri, 16 Aug 2019 13:31:20 -0300 From: Jason Gunthorpe To: Jan Kara Cc: Jerome Glisse , Vlastimil Babka , John Hubbard , Ira Weiny , Andrew Morton , Christoph Hellwig , Dan Williams , Dave Chinner , LKML , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-rdma@vger.kernel.org Subject: Re: [RFC PATCH 2/2] mm/gup: introduce vaddr_pin_pages_remote() Message-ID: <20190816163120.GF5398@ziepe.ca> References: <90e5cd11-fb34-6913-351b-a5cc6e24d85d@nvidia.com> <20190814234959.GA463@iweiny-DESK2.sc.intel.com> <2cbdf599-2226-99ae-b4d5-8909a0a1eadf@nvidia.com> <20190815132622.GG14313@quack2.suse.cz> <20190815133510.GA21302@quack2.suse.cz> <0d6797d8-1e04-1ebe-80a7-3d6895fe71b0@suse.cz> <20190816154404.GF3041@quack2.suse.cz> <20190816155220.GC3149@redhat.com> <20190816161355.GL3041@quack2.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190816161355.GL3041@quack2.suse.cz> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Aug 16, 2019 at 06:13:55PM +0200, Jan Kara wrote: > > For 3 we do not need to take a reference at all :) So just forget about 3 > > it does not exist. For 3 the reference is the reference the CPU page table > > has on the page and that's it. GUP is no longer involve in ODP or anything > > like that. > > Yes, I understand. But the fact is that GUP calls are currently still there > e.g. in ODP code. If you can make the code work without taking a page > reference at all, I'm only happy :) We are working on it :) Jason