From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758123Ab3BEWOB (ORCPT ); Tue, 5 Feb 2013 17:14:01 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:42102 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758101Ab3BEWNe (ORCPT ); Tue, 5 Feb 2013 17:13:34 -0500 Date: Tue, 5 Feb 2013 14:13:32 -0800 From: Andrew Morton To: Johannes Weiner Cc: Zhang Yanfei , Linux MM , mgorman@suse.de, minchan@kernel.org, kamezawa.hiroyu@jp.fujitsu.com, m.szyprowski@samsung.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/3] mm: rename confusing function names Message-Id: <20130205141332.04fcceac.akpm@linux-foundation.org> In-Reply-To: <20130205192640.GC6481@cmpxchg.org> References: <51113CE3.5090000@gmail.com> <20130205192640.GC6481@cmpxchg.org> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 5 Feb 2013 14:26:40 -0500 Johannes Weiner wrote: > On Wed, Feb 06, 2013 at 01:09:55AM +0800, Zhang Yanfei wrote: > > Function nr_free_zone_pages, nr_free_buffer_pages and nr_free_pagecache_pages > > are horribly badly named, they count present_pages - pages_high within zones > > instead of free pages, so why not rename them to reasonable names, not cofusing > > people. > > > > patch2 and patch3 are based on patch1. So please apply patch1 first. > > > > Zhang Yanfei (3): > > mm: rename nr_free_zone_pages to nr_free_zone_high_pages > > mm: rename nr_free_buffer_pages to nr_free_buffer_high_pages > > mm: rename nr_free_pagecache_pages to nr_free_pagecache_high_pages > > I don't feel that this is an improvement. > > As you said, the "free" is already misleading, because those pages > might all be allocated. "High" makes me think not just of highmem, > but drug abuse in general. > > nr_available_*_pages? I don't know, but if we go through with all > that churn, it had better improve something. Yes, those names are ghastly. Here's an idea: accurately document the functions with code comments. Once this is done, that documentation may well suggest a good name ;) While we're there, please note that nr_free_buffer_pages() has a *lot* of callers. Generally it's code which is trying to work out what is an appropriate size for preallocated caching space, lookup tables, etc. That's a rather hopeless objective, given memory hotplug, mlock, etc. But please do take a look at *why* these callers are calling nr_free_buffer_pages() and let's ensure that both the implementation and name are appropriate to their requirements.