From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 11 Oct 2000 07:38:08 -0400 (EDT) From: Eric Lowe Subject: Re: 2.4.0test9 vm: disappointing streaming i/o under load In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Chris Evans Cc: linux-mm@kvack.org List-ID: Hello, > Finally got round to checking out 2.4.0test9. > > Unfortunately, 2.4.0test9 exhibits poor streaming i/o performance when > under a bit of memory pressure. > > The test is this: boot with mem=32M, log onto GNOME and start xmms playing > a big .wav ripped from a CD (this requires 100-200k read i/o per second). > > Then, I start then kill netscape. I then started a find / and started > gnumeric firing up at the same time. Would you try setting /proc/sys/vm/page-cluster to 8 or 16 and let me know the results? I think one _part_ of the problem is that when the swapper isn't agressive enough, it causes too much disk thrashing which gets in the way of normal I/O... my experience has been that with modern disks with 512K+ cache you have to write in 64K clusters to get optimum throughput. Eric -- 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/