From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 785DC6B0044 for ; Fri, 18 Dec 2009 00:18:07 -0500 (EST) Date: Fri, 18 Dec 2009 06:17:54 +0100 From: Ingo Molnar Subject: Re: [mm][RFC][PATCH 0/11] mm accessor updates. Message-ID: <20091218051754.GC417@elte.hu> References: <20091217084046.GA9804@basil.fritz.box> <1261039534.27920.67.camel@laptop> <20091217085430.GG9804@basil.fritz.box> <20091217144551.GA6819@linux.vnet.ibm.com> <20091217175338.GL9804@basil.fritz.box> <20091217190804.GB6788@linux.vnet.ibm.com> <20091217195530.GM9804@basil.fritz.box> <1261080855.27920.807.camel@laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: owner-linux-mm@kvack.org To: Christoph Lameter Cc: Peter Zijlstra , Andi Kleen , "Paul E. McKenney" , KAMEZAWA Hiroyuki , "linux-kernel@vger.kernel.org" , "linux-mm@kvack.org" , "akpm@linux-foundation.org" , minchan.kim@gmail.com List-ID: * Christoph Lameter wrote: > On Thu, 17 Dec 2009, Peter Zijlstra wrote: > > > > That is why I think that the accessors are a good first step. > > > > They're not, they're daft, they operate on a global resource mm_struct, > > that's the whole problem, giving it a different name isn't going to solve > > anything. > > It is not about naming. The accessors hide the locking mechanism for > mmap_sem. Then you can change the locking in a central place. > > The locking may even become configurable later. Maybe an embedded solution > will want the existing scheme but dual quad socket may want a distributed > reference counter to avoid bouncing cachelines on faults. Hiding the locking is pretty much the worst design decision one can make. Ingo -- 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/ . Don't email: email@kvack.org