From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Cox Message-Id: <200007171446.KAA07554@devserv.devel.redhat.com> Subject: Re: [PATCH] 2.2.17pre7 VM enhancement Re: I/O performance on Date: Mon, 17 Jul 2000 10:46:11 -0400 (EDT) In-Reply-To: <200007170709.DAA27512@ocelot.cc.gatech.edu> from "Yannis Smaragdakis" at Jul 17, 2000 03:09:06 AM MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Yannis Smaragdakis Cc: Rik van Riel , Andrea Arcangeli , "Stephen C. Tweedie" , Marcelo Tosatti , Jens Axboe , Alan Cox , Derek Martin , davem@redhat.com, linux-mm@kvack.org List-ID: > Both will cause exactly one page fault. Also, one should be cautious of > pages that are brought in RAM, touched many times, but then stay untouched > for a long time. Frequency should never outweigh recency--the latter is > a better predictor, as OS designers have found since the early 70s. Modern OS designers are consistently seeing LFU work better. In our case this is partly theory in the FreeBSD case its proven by trying it. > pages we recently evicted), we adapt it by evicting more recently > touched pages (sounds hacky, but it is actually very clean). > > The results are very good (even better than in the paper, as we have > improved the algorithm since). Interesting -- 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/