From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber Costa Subject: Re: [PATCH 4/4] Add a timer to allow the separation of consigned from steal time. Date: Thu, 7 Feb 2013 12:46:04 +0400 Message-ID: <511369CC.6050405@parallels.com> References: <20130205214818.4615.12937.stgit@lambeau> <20130205214941.4615.29852.stgit@lambeau> <51126A84.5050005@parallels.com> <51129BEA.6090302@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: , , , , , , , To: Michael Wolf Return-path: Received: from mx2.parallels.com ([64.131.90.16]:47534 "EHLO mx2.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752208Ab3BGIpp (ORCPT ); Thu, 7 Feb 2013 03:45:45 -0500 In-Reply-To: <51129BEA.6090302@linux.vnet.ibm.com> Sender: kvm-owner@vger.kernel.org List-ID: On 02/06/2013 10:07 PM, Michael Wolf wrote: > On 02/06/2013 08:36 AM, Glauber Costa wrote: >> On 02/06/2013 01:49 AM, Michael Wolf wrote: >>> Add a helper routine to scheduler/core.c to allow the kvm module >>> to retrieve the cpu hardlimit settings. The values will be used >>> to set up a timer that is used to separate the consigned from the >>> steal time. >> Sorry: What is the business of a timer in here? >> Whenever we read steal time, we know how much time has passed and with >> that information we can know the entitlement for the period. This breaks >> if we suspend, but we know that we suspended, so this is not a problem. > I may be missing something, but how do we know how much time has > passed? That is why > I had the timer in there. I will go look again at the code but I > thought the data was collected > as ticks and passed at random times. The ticks are also accumulating so > we are looking at the > difference in the count between reads..... They can be collected at random times, but you can of course record the time in which it happened.