From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 20 Sep 2001 10:02:45 -0300 (BRST) From: Rik van Riel Subject: Re: broken VM in 2.4.10-pre9 In-Reply-To: <20010919.145534.104033668.davem@redhat.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: "David S. Miller" Cc: ebiederm@xmission.com, alan@lxorguk.ukuu.org.uk, phillips@bonn-fries.net, rfuller@nsisoftware.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Wed, 19 Sep 2001, David S. Miller wrote: > My own personal feeling, after having tried to implement a much > lighter weight scheme involving "anon areas", is that reverse maps or > something similar should be looked at as a latch ditch effort. > > We are tons faster than anyone else in fork/exec/exit precisely > because we keep track of so little state for anonymous pages. Thinking about this some more, it would seem that the "perfect fork()" would be one where you DON'T copy the page tables, but only set the parent's page tables to read-only and point the VMAs of the child at some kind of memory objects. For example, for file-backed VMAs we might already skip the page table copying right now. regards, Rik -- IA64: a worthy successor to i860. http://www.surriel.com/ http://distro.conectiva.com/ Send all your spam to aardvark@nl.linux.org (spam digging piggy) -- 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/