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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 DD8A2C432C0 for ; Thu, 21 Nov 2019 08:33:46 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 95DF520718 for ; Thu, 21 Nov 2019 08:33:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 95DF520718 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 47JXs42CN7zDr10 for ; Thu, 21 Nov 2019 19:33:44 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lst.de (client-ip=213.95.11.211; helo=verein.lst.de; envelope-from=hch@lst.de; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=lst.de Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 47JXBp2x1JzDr1D for ; Thu, 21 Nov 2019 19:04:02 +1100 (AEDT) Received: by verein.lst.de (Postfix, from userid 2407) id C80DF68BFE; Thu, 21 Nov 2019 09:03:56 +0100 (CET) Date: Thu, 21 Nov 2019 09:03:56 +0100 From: Christoph Hellwig To: John Hubbard Subject: Re: [PATCH v7 02/24] mm/gup: factor out duplicate code from four routines Message-ID: <20191121080356.GA24784@lst.de> References: <20191121071354.456618-1-jhubbard@nvidia.com> <20191121071354.456618-3-jhubbard@nvidia.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191121071354.456618-3-jhubbard@nvidia.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Michal Hocko , Jan Kara , kvm@vger.kernel.org, linux-doc@vger.kernel.org, David Airlie , Dave Chinner , dri-devel@lists.freedesktop.org, LKML , linux-mm@kvack.org, Paul Mackerras , linux-kselftest@vger.kernel.org, Ira Weiny , Christoph Hellwig , Jonathan Corbet , linux-rdma@vger.kernel.org, Christoph Hellwig , Jason Gunthorpe , Vlastimil Babka , =?iso-8859-1?Q?Bj=F6rn_T=F6pel?= , linux-media@vger.kernel.org, Shuah Khan , linux-block@vger.kernel.org, =?iso-8859-1?B?Suly9G1l?= Glisse , Al Viro , Dan Williams , Mauro Carvalho Chehab , bpf@vger.kernel.org, Magnus Karlsson , Jens Axboe , netdev@vger.kernel.org, Alex Williamson , Daniel Vetter , "Aneesh Kumar K . V" , linux-fsdevel@vger.kernel.org, Andrew Morton , linuxppc-dev@lists.ozlabs.org, "David S . Miller" , Mike Kravetz Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" On Wed, Nov 20, 2019 at 11:13:32PM -0800, John Hubbard wrote: > There are four locations in gup.c that have a fair amount of code > duplication. This means that changing one requires making the same > changes in four places, not to mention reading the same code four > times, and wondering if there are subtle differences. > > Factor out the common code into static functions, thus reducing the > overall line count and the code's complexity. > > Also, take the opportunity to slightly improve the efficiency of the > error cases, by doing a mass subtraction of the refcount, surrounded > by get_page()/put_page(). > > Also, further simplify (slightly), by waiting until the the successful > end of each routine, to increment *nr. Any reason for the spurious underscore in the function name? Otherwise this looks fine and might be a worthwhile cleanup to feed Andrew for 5.5 independent of the gut of the changes. Reviewed-by: Christoph Hellwig