From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 9 Oct 2000 20:11:33 -0300 (BRST) From: Rik van Riel Subject: Re: Write-back/VM question In-Reply-To: <39E25034.6B1203CE@sgi.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Rajagopal Ananthanarayanan Cc: linux-mm@kvack.org List-ID: On Mon, 9 Oct 2000, Rajagopal Ananthanarayanan wrote: > One of the behaviors of the new VM seems to be that it starts > I/O on a written page fairly early. This "aggressive" write is > great for streaming I/O, but seems to have a penalty when the > application has write-locality. Dbench is a one case, which is > write intensive and a lot of the writes are to a previously > written page. > > I'm not exactly certain why starting write-out early would cause > problems, but I've a couple of quick questions: > > 1. Is the page locked during write-out? The buffers on the page are. I'm not sure about the page itself though ... > 2. Is there a tuneable that I can use to > control write-back behaviour? /proc/sys/vm/bdflush, first value 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/