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=-2.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 98187C3A589 for ; Tue, 20 Aug 2019 08:18:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 685DF23AA7 for ; Tue, 20 Aug 2019 08:18:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566289104; bh=wEI2KC2m1XzGfOGS6X399yBP/45s+3KPbWStKXi0BIU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=fdeMtogeTF6OSqgaAShxDOwo2S5n/0ALnIK3QV3SQwZsHfpQmbjEebW2QyvUq8ey/ Fy/6erIgPRIEuF4OfzYOotIct1Y26CLBKCaJli1q9F3+TD+mMgY/DSnTYit7dq5DGD cnhKHhi3FMVD+DAxjjYujMVrE+gC/LUy2xQM8VTs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729443AbfHTISX (ORCPT ); Tue, 20 Aug 2019 04:18:23 -0400 Received: from mx2.suse.de ([195.135.220.15]:51218 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729150AbfHTISX (ORCPT ); Tue, 20 Aug 2019 04:18:23 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 956A7AEA1; Tue, 20 Aug 2019 08:18:21 +0000 (UTC) Date: Tue, 20 Aug 2019 10:18:20 +0200 From: Michal Hocko To: John Hubbard Cc: Bharath Vedartham , Dimitri Sivanich , Andrew Morton , jglisse@redhat.com, ira.weiny@intel.com, gregkh@linuxfoundation.org, arnd@arndb.de, william.kucharski@oracle.com, hch@lst.de, inux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-kernel-mentees@lists.linuxfoundation.org, linux-kernel@vger.kernel.org Subject: Re: [Linux-kernel-mentees][PATCH v6 1/2] sgi-gru: Convert put_page() to put_user_page*() Message-ID: <20190820081820.GI3111@dhcp22.suse.cz> References: <1566157135-9423-1-git-send-email-linux.bhar@gmail.com> <1566157135-9423-2-git-send-email-linux.bhar@gmail.com> <20190819125611.GA5808@hpe.com> <20190819190647.GA6261@bharath12345-Inspiron-5559> <0c2ad29b-934c-ec30-66c3-b153baf1fba5@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0c2ad29b-934c-ec30-66c3-b153baf1fba5@nvidia.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 19-08-19 12:30:18, John Hubbard wrote: > On 8/19/19 12:06 PM, Bharath Vedartham wrote: > > On Mon, Aug 19, 2019 at 07:56:11AM -0500, Dimitri Sivanich wrote: > > > Reviewed-by: Dimitri Sivanich > > Thanks! > > > > John, would you like to take this patch into your miscellaneous > > conversions patch set? > > > > (+Andrew and Michal, so they know where all this is going.) > > Sure, although that conversion series [1] is on a brief hold, because > there are additional conversions desired, and the API is still under > discussion. Also, reading between the lines of Michal's response [2] > about it, I think people would prefer that the next revision include > the following, for each conversion site: > > Conversion of gup/put_page sites: > > Before: > > get_user_pages(...); > ... > for each page: > put_page(); > > After: > > gup_flags |= FOLL_PIN; (maybe FOLL_LONGTERM in some cases) > vaddr_pin_user_pages(...gup_flags...) I was hoping that FOLL_PIN would be handled by vaddr_pin_user_pages. > ... > vaddr_unpin_user_pages(); /* which invokes put_user_page() */ > > Fortunately, it's not harmful for the simpler conversion from put_page() > to put_user_page() to happen first, and in fact those have usually led > to simplifications, paving the way to make it easier to call > vaddr_unpin_user_pages(), once it's ready. (And showing exactly what > to convert, too.) If that makes the later conversion easier then no real objections from me. Assuming that the current put_user_page conversions are correct of course (I have the mlock one and potentials that falls into the same category in mind). -- Michal Hocko SUSE Labs