Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755394AbZFEGdo (ORCPT ); Fri, 5 Jun 2009 02:33:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752180AbZFEGde (ORCPT ); Fri, 5 Jun 2009 02:33:34 -0400 Received: from e38.co.us.ibm.com ([32.97.110.159]:33423 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751937AbZFEGdd (ORCPT ); Fri, 5 Jun 2009 02:33:33 -0400 Date: Fri, 5 Jun 2009 12:02:43 +0530 From: Bharata B Rao To: Avi Kivity Cc: balbir@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 Subject: Re: [RFC] CPU hard limits Message-ID: <20090605063243.GC3872@in.ibm.com> Reply-To: bharata@linux.vnet.ibm.com References: <4A27BBCA.5020606@redhat.com> <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> <4A28B539.3050001@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4A28B539.3050001@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1177 Lines: 31 On Fri, Jun 05, 2009 at 09:03:37AM +0300, Avi Kivity wrote: > Balbir Singh wrote: >>> I think so. Given guarantees G1..Gn (0 <= Gi <= 1; sum(Gi) <= 1), >>> and a cpu hog running in each group, how would the algorithm divide >>> resources? >>> >>> >> >> As per the matrix calculation, but as soon as we reach an idle point, >> we redistribute the b/w and start a new quantum so to speak, where all >> groups are charged up to their hard limits. >> >> For your question, if there is a CPU hog running, it would be as per >> the matrix calculation, since the system has no idle point during the >> bandwidth period. >> > > So the groups with guarantees get a priority boost. That's not a good > side effect. That happens only in the presence of idle cycles when other groups [with or without guarantees] have nothing useful to do. So how would that matter since there is nothing else to run anyway ? Regards, Bharata. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/