From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH] 2.2.17pre7 VM enhancement Re: I/O performance on 2.4.0-test2 References: From: "Juan J. Quintela" In-Reply-To: Andrea Arcangeli's message of "Tue, 11 Jul 2000 19:54:31 +0200 (CEST)" Date: 11 Jul 2000 20:03:41 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: owner-linux-mm@kvack.org Return-Path: To: Andrea Arcangeli Cc: Rik van Riel , "Stephen C. Tweedie" , Marcelo Tosatti , Jens Axboe , Alan Cox , Derek Martin , Linux Kernel , linux-mm@kvack.org, "David S. Miller" List-ID: >>>>> "andrea" == Andrea Arcangeli writes: andrea> On Tue, 11 Jul 2000, Rik van Riel wrote: >> This is why LRU is wrong and we need page aging (which >> approximates both LRU and NFU). >> >> The idea is to remove those pages from memory which will >> not be used again for the longest time, regardless of in >> which 'state' they live in main memory. >> >> (and proper page aging is a good approximation to this) andrea> It will still drop _all_ VM mappings from memory if you left "cp /dev/zero andrea> ." in background for say 2 hours. This in turn mean that during streming andrea> I/O you'll have _much_ more than the current swapin/swapout troubles. If you are copying in the background a cp and you don't touch your vi/emacs/whatever pages in 2 hours (i.e. age = 0) then I think that it is ok for that pages to be swaped out. Notice that the cage pages will have _initial age_ and the pages of the binaries will have an _older_ age. Later, Juan. -- In theory, practice and theory are the same, but in practice they are different -- Larry McVoy -- 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/