From: Glauber Costa <glommer@redhat.com>
To: Peter Zijlstra <peterz@infradead.org>
Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
aliguori@us.ibm.com, Rik van Riel <riel@redhat.com>,
Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>,
Avi Kivity <avi@redhat.com>
Subject: Re: [PATCH 16/16] KVM-GST: adjust scheduler cpu power
Date: Tue, 25 Jan 2011 18:02:36 -0200 [thread overview]
Message-ID: <1295985756.15920.33.camel@mothafucka.localdomain> (raw)
In-Reply-To: <1295898690.28776.472.camel@laptop>
On Mon, 2011-01-24 at 20:51 +0100, Peter Zijlstra wrote:
> On Mon, 2011-01-24 at 16:51 -0200, Glauber Costa wrote:
> > > I would really much rather see you change update_rq_clock_task() and
> > > subtract your ns resolution steal time from our wall-time,
> > > update_rq_clock_task() already updates the cpu_power relative to the
> > > remaining time available.
> >
> > But then we get into the problems we already discussed in previous
> > submissions, which is, we don't really want to alter any notion of
> > wallclock time. Could you list any more concrete advantages of the
> > specific way you proposed?
>
> clock_task is the time spend on the task, by not taking steal time into
> account all steal time is accounted as service to whatever task was
> current when the vcpu wasn't running.
>
> It doesn't change wall-time in the sense of gtod, only the service time
> to tasks.
I fail to see how does clock_task influence cpu power.
If we also have to touch clock_task for better accounting of other
stuff, it is a separate story.
But for cpu_power, I really fail. Please enlighten me.
I did have slightly better results accounting the whole steal time
period away from total_"ticks"(*) than just with units.
* Please note again that ticks here is just a (bad, I admit) name.
This is not tick accounting, is just an estimate of how much useful work
your cpu did.
next prev parent reply other threads:[~2011-01-25 20:03 UTC|newest]
Thread overview: 57+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-24 18:06 [PATCH 00/16] New Proposal for steal time in KVM Glauber Costa
2011-01-24 18:06 ` [PATCH 01/16] KVM-HDR: register KVM basic header infrastructure Glauber Costa
2011-01-26 11:06 ` Avi Kivity
2011-01-26 12:13 ` Glauber Costa
2011-01-26 15:12 ` Avi Kivity
2011-01-26 15:36 ` Glauber Costa
2011-01-26 17:22 ` Anthony Liguori
2011-01-26 17:49 ` Glauber Costa
2011-01-27 12:31 ` Avi Kivity
2011-01-24 18:06 ` [PATCH 02/16] KVM-HV: KVM - KVM Virtual Memory hypervisor implementation Glauber Costa
2011-01-24 18:06 ` [PATCH 03/16] KVM-HDR: KVM Userspace registering ioctl Glauber Costa
2011-01-26 11:12 ` Avi Kivity
2011-01-26 12:14 ` Glauber Costa
2011-01-26 15:14 ` Avi Kivity
2011-01-26 15:23 ` Glauber Costa
2011-01-24 18:06 ` [PATCH 04/16] KVM-HV: " Glauber Costa
2011-01-24 18:06 ` [PATCH 05/16] KVM-HDR: Implement wallclock over KVM - KVM Virtual Memory Glauber Costa
2011-01-26 11:13 ` Avi Kivity
2011-01-26 12:20 ` Glauber Costa
2011-01-26 15:17 ` Avi Kivity
2011-01-26 15:45 ` Glauber Costa
2011-01-27 12:17 ` Avi Kivity
2011-01-24 18:06 ` [PATCH 06/16] " Glauber Costa
2011-01-24 18:06 ` [PATCH 07/16] KVM-GST: " Glauber Costa
2011-01-24 18:06 ` [PATCH 08/16] KVM-HDR: Implement kvmclock systemtime " Glauber Costa
2011-01-24 18:06 ` [PATCH 09/16] KVM-HV: " Glauber Costa
2011-01-24 18:06 ` [PATCH 10/16] KVM-GST: " Glauber Costa
2011-01-24 18:06 ` [PATCH 11/16] KVM-HDR: KVM Steal time implementation Glauber Costa
2011-01-24 23:06 ` Rik van Riel
2011-01-24 18:06 ` [PATCH 12/16] KVM-HV: " Glauber Costa
2011-01-24 23:15 ` Rik van Riel
2011-01-24 18:06 ` [PATCH 13/16] KVM-HV: KVM Steal time calculation Glauber Costa
2011-01-24 23:20 ` Rik van Riel
2011-01-24 18:06 ` [PATCH 14/16] KVM-GST: KVM Steal time registration Glauber Costa
2011-01-24 23:27 ` Rik van Riel
2011-01-24 23:31 ` Rik van Riel
2011-01-25 1:25 ` Glauber Costa
2011-01-25 1:26 ` Rik van Riel
2011-01-25 1:28 ` Glauber Costa
2011-01-24 18:06 ` [PATCH 15/16] KVM-GST: KVM Steal time accounting Glauber Costa
2011-01-24 23:33 ` Rik van Riel
2011-01-24 18:06 ` [PATCH 16/16] KVM-GST: adjust scheduler cpu power Glauber Costa
2011-01-24 18:32 ` Peter Zijlstra
2011-01-24 18:51 ` Glauber Costa
2011-01-24 19:51 ` Peter Zijlstra
2011-01-24 19:57 ` Glauber Costa
2011-01-25 20:02 ` Glauber Costa [this message]
2011-01-25 20:13 ` Peter Zijlstra
2011-01-25 20:47 ` Glauber Costa
2011-01-25 21:07 ` Peter Zijlstra
2011-01-25 21:27 ` Glauber Costa
2011-01-26 9:57 ` Peter Zijlstra
2011-01-26 15:43 ` Glauber Costa
2011-01-26 16:46 ` Peter Zijlstra
2011-01-26 16:53 ` Peter Zijlstra
2011-01-26 18:11 ` Glauber Costa
2011-01-24 19:53 ` Peter Zijlstra
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