From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: broken VM in 2.4.10-pre9 Date: Wed, 19 Sep 2001 20:45:55 +0100 (BST) In-Reply-To: <20010919093828Z17304-2759+92@humbolt.nl.linux.org> from "Daniel Phillips" at Sep 19, 2001 11:45:44 AM MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: From: Alan Cox Sender: owner-linux-mm@kvack.org Return-Path: To: Daniel Phillips Cc: "Eric W. Biederman" , Rob Fuller , linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: > On September 17, 2001 06:03 pm, Eric W. Biederman wrote: > > In linux we have avoided reverse maps (unlike the BSD's) which tends > > to make the common case fast at the expense of making it more > > difficult to handle times when the VM system is under extreme load and > > we are swapping etc. > > What do you suppose is the cost of the reverse map? I get the impression you > think it's more expensive than it is. We can keep the typical page table cost lower than now (including reverse maps) just by doing some common sense small cleanups to get the page struct down to 48 bytes on x86 -- 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/