From mboxrd@z Thu Jan 1 00:00:00 1970 From: Shaun Reitan Subject: Re: VM disk I/O limit patch Date: Thu, 23 Jun 2011 13:45:36 -0700 Message-ID: References: <20110621162935.F4A1.3A8D29D5@cloudex.cn> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110621162935.F4A1.3A8D29D5@cloudex.cn> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com Cc: xen-users@lists.xensource.com List-Id: xen-devel@lists.xenproject.org Does this match only limit throughput or can it also limit the guest by disk IOPS? christopher aker had a patch way back for UML that did disk based qos. What i really liked about that patch was that it allowed for bursting by using a bucket. If i remember correctly you specified that a guest's bucket could hold say 4000 tokens, and the bucket would be filled with 10 tokens a second. Each IO took one token from the bucket. When the bucket was empty IO was paused and processed as the bucket was filled. This allowed a guest to burst for a short period of time until that bucket was empty and then it would slowely be filled back up. Also what was nice is that the guest had a /proc/ entry that told the customer how many tokens they currently had in their bucket. I would like to see somthing like this in Xen, I've even thought about posting to the devel forums seeing if somebody wanted to write one for $$$ ~Shaun