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=DKIMWL_WL_HIGH,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 BDF5DC2D0C0 for ; Thu, 19 Dec 2019 05:52:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7C0992146E for ; Thu, 19 Dec 2019 05:52:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="GK/0OEzM" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725996AbfLSFwA (ORCPT ); Thu, 19 Dec 2019 00:52:00 -0500 Received: from hqnvemgate24.nvidia.com ([216.228.121.143]:8462 "EHLO hqnvemgate24.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725821AbfLSFv7 (ORCPT ); Thu, 19 Dec 2019 00:51:59 -0500 Received: from hqpgpgate102.nvidia.com (Not Verified[216.228.121.13]) by hqnvemgate24.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Wed, 18 Dec 2019 21:51:18 -0800 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate102.nvidia.com (PGP Universal service); Wed, 18 Dec 2019 21:51:48 -0800 X-PGP-Universal: processed; by hqpgpgate102.nvidia.com on Wed, 18 Dec 2019 21:51:48 -0800 Received: from [10.2.165.11] (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 19 Dec 2019 05:51:47 +0000 Subject: Re: [PATCH v11 04/25] mm: devmap: refactor 1-based refcounting for ZONE_DEVICE pages To: Dan Williams CC: Andrew Morton , Al Viro , Alex Williamson , Benjamin Herrenschmidt , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Christoph Hellwig , Daniel Vetter , Dave Chinner , David Airlie , "David S . Miller" , Ira Weiny , Jan Kara , Jason Gunthorpe , Jens Axboe , Jonathan Corbet , =?UTF-8?B?SsOpcsO0bWUgR2xpc3Nl?= , Magnus Karlsson , Mauro Carvalho Chehab , Michael Ellerman , Michal Hocko , Mike Kravetz , Paul Mackerras , Shuah Khan , Vlastimil Babka , , Maling list - DRI developers , KVM list , , Linux Doc Mailing List , linux-fsdevel , , "Linux-media@vger.kernel.org" , linux-rdma , linuxppc-dev , Netdev , Linux MM , LKML , Christoph Hellwig References: <20191216222537.491123-1-jhubbard@nvidia.com> <20191216222537.491123-5-jhubbard@nvidia.com> From: John Hubbard X-Nvconfidentiality: public Message-ID: Date: Wed, 18 Dec 2019 21:48:57 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.0 MIME-Version: 1.0 In-Reply-To: X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL111.nvidia.com (172.20.187.18) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1576734679; bh=sCXlmkq8dxoo2tHizwzufCVV/oUf7NWxJHJ14roWTmw=; h=X-PGP-Universal:Subject:To:CC:References:From:X-Nvconfidentiality: Message-ID:Date:User-Agent:MIME-Version:In-Reply-To: X-Originating-IP:X-ClientProxiedBy:Content-Type:Content-Language: Content-Transfer-Encoding; b=GK/0OEzMPk1mXpB/B4W5MjyKB4KjAD7QACyt/PluTqMpD63escvQAFpT8GgKashz/ zjYVekQ9+jMFWBNLeBd0fSneuL/0IcIp4C+grDhfKeP4gGgfiF1yVdsXHIqTikTNBn TjGaizVxBY5MAKFT0ZuOTKaGbWetrkck9KS2raRunh97qgKrmKFpIg4PPwbiRz76za exoRNucmh5b5u8c4Keiv+48zYJosbfMH0xFWea2gmmlHUZQmtMFnoE6IBRYKWSfpwI AlXqgbv15vIdEK38umLQ7xsD0bruDuQcBNHLMX9Mt0huC0EASH9bq+0C+xF+Z7vdfg E3ondtFacFVjg== Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 12/18/19 9:27 PM, Dan Williams wrote: ... >> @@ -461,5 +449,5 @@ void __put_devmap_managed_page(struct page *page) >> page->mapping = NULL; >> page->pgmap->ops->page_free(page); >> } >> -EXPORT_SYMBOL(__put_devmap_managed_page); >> +EXPORT_SYMBOL(free_devmap_managed_page); > > This patch does not have a module consumer for > free_devmap_managed_page(), so the export should move to the patch > that needs the new export. Hi Dan, OK, I know that's a policy--although it seems quite pointless here given that this is definitely going to need an EXPORT. At the moment, the series doesn't use it in any module at all, so I'll just delete the EXPORT for now. > > Also the only reason that put_devmap_managed_page() is EXPORT_SYMBOL > instead of EXPORT_SYMBOL_GPL is that there was no practical way to > hide the devmap details from evey module in the kernel that did > put_page(). I would expect free_devmap_managed_page() to > EXPORT_SYMBOL_GPL if it is not inlined into an existing exported > static inline api. > Sure, I'll change it to EXPORT_SYMBOL_GPL when the time comes. We do have to be careful that we don't shut out normal put_page() types of callers, but...glancing through the current callers, that doesn't look to be a problem. Good. So it should be OK to do EXPORT_SYMBOL_GPL here. Are you *sure* you don't want to just pre-emptively EXPORT now, and save looking at it again? thanks, -- John Hubbard NVIDIA