From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.12] helo=sc8-sf-mx2.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1B7aUp-00051G-4j for user-mode-linux-devel@lists.sourceforge.net; Sun, 28 Mar 2004 05:38:39 -0800 Received: from ns.theshore.net ([216.156.129.65] helo=www.theshore.net) by sc8-sf-mx2.sourceforge.net with esmtp (Exim 4.30) id 1B7aUn-0005Lf-Ka for user-mode-linux-devel@lists.sourceforge.net; Sun, 28 Mar 2004 05:38:37 -0800 Message-ID: <002b01c414ca$5f439370$0201a8c0@hawk> From: "Christopher S. Aker" References: <004901c414a3$f4d28a80$0201a8c0@hawk> <0c2101c414c0$3b2c6ca0$2000000a@schlepptopp> Subject: Re: [uml-devel] [PATCH] I/O-Request Token Bucket Limiter MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Sender: user-mode-linux-devel-admin@lists.sourceforge.net Errors-To: user-mode-linux-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: The user-mode Linux development list List-Post: List-Help: List-Subscribe: , List-Archive: Date: Sun, 28 Mar 2004 07:41:26 -0600 To: roland , uml-devel > hello christoph, > could you please explain (in a simple way), what your patch can be used for? > from my point of understanding, we now can limit the maximum i/o bandwidth a single uml can use? > is that right? > i have difficulties in understanding the meaning of token/bucket/filter. It allows you to place a limit on the amount of disk I/O that makes it to the host from each UML. It is useful in the case where a mis-configured UML is thrashing its swapfile, and in turn consuming a lot of I/O on the host and starving the other UMLs of precious disk time. The useful thing about the TBF is that it allows an initial burstable, unrestricted rate until the token bucket is empty. The variable token_max (the size of the bucket) becomes how much "burstable" I/O to provide to the UML before it starts limiting the rate. Each I/O request takes one token from io_tokens, but every second token_refill is added to io_tokens (to a maximum of token_max). A way to see this is in action is to apply the patch, run the UML, and then on the host: [root@host ~]# watch "uml_mconsole /path/to/mconsole/socket io_status 2>/dev/null " And then: [user@uml ~] dd if=/dev/zero of=/bigfile bs=1M count=200 (or some other I/O generating activity) and watch the mconsole io_status output... -Chris ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ User-mode-linux-devel mailing list User-mode-linux-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-devel