From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail144.messagelabs.com (mail144.messagelabs.com [216.82.254.51]) by kanga.kvack.org (Postfix) with ESMTP id 1B9F68D003B for ; Wed, 20 Apr 2011 07:20:26 -0400 (EDT) Received: by bwz17 with SMTP id 17so793279bwz.14 for ; Wed, 20 Apr 2011 04:20:22 -0700 (PDT) Content-Type: text/plain; charset=utf-8; format=flowed; delsp=yes Subject: Re: [PATCH 0/1] mm: make read-only accessors take const pointer parameters References: <1302861377-8048-1-git-send-email-ext-phil.2.carmody@nokia.com> <20110415145133.GO15707@random.random> <20110415155916.GD7112@esdhcp04044.research.nokia.com> <20110415160957.GV15707@random.random> <1303291717.2700.20.camel@localhost> Date: Wed, 20 Apr 2011 13:20:19 +0200 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit From: "Michal Nazarewicz" Message-ID: In-Reply-To: <1303291717.2700.20.camel@localhost> Sender: owner-linux-mm@kvack.org List-ID: To: Andrea Arcangeli , Artem Bityutskiy Cc: Phil Carmody , akpm@linux-foundation.org, cl@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org On Wed, 20 Apr 2011 11:28:37 +0200, Artem Bityutskiy wrote: > I think it is good when small core functions like this are strict and > use 'const' whenever possible, even though 'const' is so imperfect in C. > > Let me give an example from my own experience. I was writing code which > was using the kernel RB trees, and I was trying to be strict and use > 'const' whenever possible. But because the core functions like 'rb_next' > do not have 'const' modifier, I could not use const in many many places > of my code, because gcc was yelling. And I was not very enthusiastic to > touch the RB-tree code that time. The problem is that you end up with two sets of functions (one taking const another taking non-const), a bunch of macros or a function that takes const but returns non-const. If we settle on anything I would probably vote for the last option but the all are far from ideal. -- Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=./ `o ..o | Computer Science, Michal "mina86" Nazarewicz (o o) ooo +----------ooO--(_)--Ooo-- -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org