From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Chris Friesen" Subject: Re: [RFC] CPU hard limits Date: Fri, 05 Jun 2009 08:54:14 -0600 Message-ID: <4A293196.2060006@nortel.com> References: <20090605030309.GA3872@in.ibm.com> <4A28921C.6010802@redhat.com> <661de9470906042137u603e2997n80c270bf7f6191ad@mail.gmail.com> <4A28A2AB.3060108@redhat.com> <20090605044946.GA11755@balbir.in.ibm.com> <20090605051050.GB11755@balbir.in.ibm.com> <4A28AB67.7040800@redhat.com> <20090605052755.GE11755@balbir.in.ibm.com> <20090605053159.GB3872@in.ibm.com> <4A28B4CE.4010004@redhat.com> <20090605093947.GJ11755@balbir.in.ibm.com> <4A291A2F.3090201@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: balbir@linux.vnet.ibm.com, bharata@linux.vnet.ibm.com, linux-kernel@vger.kernel.org, Dhaval Giani , Vaidyanathan Srinivasan , Gautham R Shenoy , Srivatsa Vaddagiri , Ingo Molnar , Peter Zijlstra , Pavel Emelyanov , kvm@vger.kernel.org, Linux Containers , Herbert Poetzl To: Avi Kivity Return-path: Received: from zcars04e.nortel.com ([47.129.242.56]:45907 "EHLO zcars04e.nortel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751386AbZFEOyT (ORCPT ); Fri, 5 Jun 2009 10:54:19 -0400 In-Reply-To: <4A291A2F.3090201@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > I am selling virtual private servers. A 10% cpu share costs $x/month, > and I guarantee you'll get that 10%, or your money back. On the other > hand, I want to limit cpu usage to that 10% (maybe a little more) so > people don't buy 10% shares and use 100% on my underutilized servers. > If they want 100%, let them pay for 100%. What about taking a page from the networking folks and specifying cpu like a networking SLA? Something like "group A is guaranteed X percent (or share) of the cpu, but it is allowed to burst up to Y percent for Z milliseconds" If a rule of this form was the first-class citizen, it would provide both guarantees, limits, and flexible behaviour. Chris