From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 11 Sep 2000 14:51:47 -0300 (BRST) From: Rik van Riel Subject: Re: [PATCH] Page aging for 2.4.0-test8 In-Reply-To: <20000911114520.A22732@keymaster.enme.ucalgary.ca> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Neil Schemenauer Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org List-ID: On Mon, 11 Sep 2000, Neil Schemenauer wrote: > On Mon, Sep 11, 2000 at 01:12:32PM -0300, Rik van Riel wrote: > > Your idea /heavily/ penalises libc and executable pages by aging them > > more often than anonymous pages... > > I don't think I age anonymous pages any more than any other type > of page. Think again. You're aging them both in try_to_swap_out() /and/ in shrink_mmap(). > Perhaps you are saying that shared pages should recieve some > bonus? No. I'm saying shared pages should have the accessed bits propagated and be only aged once. I know we can't handle this right for 2.4, but for 2.5 I hope to use physical-page based page aging to get this one right... > That is a different issue and it is handled naturally with my > patch. If shared pages are actually used then PageTouch() will > be called on them more often. This is /not/ the case. Think of a page from libc, which is mapped by 30 processes. Now imagine that page is being heavily used and was used by 5 processes since we scanned it the last time. With your patch we'd age the page down 25 (!!) times and only age it up 5 times. This is clearly not what you want for a page which was used by 5 different processes since the last time we scanned it... regards, Rik -- "What you're running that piece of shit Gnome?!?!" -- Miguel de Icaza, UKUUG 2000 http://www.conectiva.com/ http://www.surriel.com/ -- 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.eu.org/Linux-MM/