From mboxrd@z Thu Jan 1 00:00:00 1970 From: Glauber Costa Subject: Re: [PATCH v2 4/6] KVM-GST: KVM Steal time registration Date: Tue, 01 Feb 2011 15:00:41 -0200 Message-ID: <1296579641.5081.27.camel@mothafucka.localdomain> References: <1296244340-15173-1-git-send-email-glommer@redhat.com> <1296244340-15173-5-git-send-email-glommer@redhat.com> <4D45649A.4090709@redhat.com> <1296575618.5081.13.camel@mothafucka.localdomain> <1296577030.26581.236.camel@laptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: Avi Kivity , kvm@vger.kernel.org, linux-kernel@vger.kernel.org, aliguori@us.ibm.com, Rik van Riel , Jeremy Fitzhardinge , Venkatesh Pallipadi To: Peter Zijlstra Return-path: In-Reply-To: <1296577030.26581.236.camel@laptop> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org > > See, that! is the problem, don't round up like that. Yeah, I was using usecs_to_cputime(), believing this was the standard interface. By the way, one of the things that also led to better results were just forcing it to 0 every time we had steal == 1 in the end. But *that* was a real hack =) > What you can do is: steal_ticks = steal_time_clock() / TICK_NSEC, or > simply keep a steal time delta and every time it overflows > cputime_one_jiffy insert a steal-time tick. What do you think about keeping accounting in msec/usec resolution and (thus allowing us to compute half a tick to user/system, other half to steal time) only change it to cputime in the last minute?