From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752290AbcGMHuk (ORCPT ); Wed, 13 Jul 2016 03:50:40 -0400 Received: from mail-wm0-f53.google.com ([74.125.82.53]:33708 "EHLO mail-wm0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750961AbcGMHuc (ORCPT ); Wed, 13 Jul 2016 03:50:32 -0400 Date: Wed, 13 Jul 2016 09:50:24 +0200 From: Michal Hocko To: Chen Gang Cc: Andrew Morton , vbabka@suse.cz, kirill.shutemov@linux.intel.com, mingo@kernel.org, dave.hansen@linux.intel.com, dan.j.williams@intel.com, hannes@cmpxchg.org, jack@suse.cz, iamjoonsoo.kim@lge.com, jmarchan@redhat.com, dingel@linux.vnet.ibm.com, oleg@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Chen Gang Subject: Re: [PATCH] mm: gup: Re-define follow_page_mask output parameter page_mask usage Message-ID: <20160713075024.GB28723@dhcp22.suse.cz> References: <1468084625-26999-1-git-send-email-chengang@emindsoft.com.cn> <20160711141702.fb1879707aa2bcb290133a43@linux-foundation.org> <578522CE.9060905@emindsoft.com.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <578522CE.9060905@emindsoft.com.cn> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed 13-07-16 01:03:10, Chen Gang wrote: > On 7/12/16 05:17, Andrew Morton wrote: > > On Sun, 10 Jul 2016 01:17:05 +0800 chengang@emindsoft.com.cn wrote: > > > >> For a pure output parameter: > >> > >> - When callee fails, the caller should not assume the output parameter > >> is still valid. > >> > >> - And callee should not assume the pure output parameter must be > >> provided by caller -- caller has right to pass NULL when caller does > >> not care about it. > > > > Sorry, I don't think this one is worth merging really. > > > > OK, thanks, I can understand. > > It will be better if provide more details: e.g. > > - This patch is incorrect, or the comments is not correct. > > - The patch is worthless, at present. I would say the patch is not really needed. The code you are touching works just fine and there is no reason to touch it unless this is a part of a larger change where future changes would be easier to review/implement. -- Michal Hocko SUSE Labs