From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 21 Apr 2002 17:23:54 -0700 From: "Martin J. Bligh" Reply-To: "Martin J. Bligh" Subject: Re: Why *not* rmap, anyway? Message-ID: <3051330941.1019409833@[10.10.2.3]> In-Reply-To: <3CC33CDF.7F48A5B3@earthlink.net> References: <3CC33CDF.7F48A5B3@earthlink.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: owner-linux-mm@kvack.org Return-Path: To: Joseph A Knapka , linux-mm@kvack.org List-ID: > I was just reading Bill's reply regaring rmap, and it > seems to me that rmap is the most obvious and clean > way to handle unmapping pages. So now I wonder why > it wasn't done that way from the beginning? Because it costs something to maintain the reverse map. If the cost exceeds the benefit, it's not worth it. That's why a bunch of us are working on bringing the cost down. At the moment the cost is especially high on larger machines, but we're getting there ... quickly ;-) Martin. -- 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/