From mboxrd@z Thu Jan 1 00:00:00 1970 Message-Id: In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Date: Thu, 7 Jun 2001 22:08:00 +0100 From: Jonathan Morton Subject: Re: Background scanning change on 2.4.6-pre1 Sender: owner-linux-mm@kvack.org Return-Path: To: Linus Torvalds , Marcelo Tosatti Cc: lkml , linux-mm@kvack.org List-ID: >> > This is going to make all pages have age 0 on an idle system after some >> > time (the old code from Rik which has been replaced by this code tried to >> > avoid that) > >There's another reason why I think the patch may be ok even without any >added logic: not only does it simplify the code and remove a illogical >heuristic, but there is nothing that really says that "age 0" is >necessarily very bad. Here's my take on it. The point of ageing is twofold - to age down pages that aren't in use, and to age up pages that *are* in use. So, pages that are in use will remain with high ages even when background scanning is being done, and pages that aren't in use will decay to zero age. I can't see what's wrong with that. When we need more memory, it's a Very Good Thing to know that most of the pages in the system haven't been accessed in yonks - we know exactly which ones we want to throw out first. -------------------------------------------------------------- from: Jonathan "Chromatix" Morton mail: chromi@cyberspace.org (not for attachments) The key to knowledge is not to rely on people to teach you it. GCS$/E/S dpu(!) s:- a20 C+++ UL++ P L+++ E W+ N- o? K? w--- O-- M++$ V? PS PE- Y+ PGP++ t- 5- X- R !tv b++ DI+++ D G e+ h+ r++ y+(*) -- 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/