Re: [Xen-ia64-devel] [PATCH][3/3] Steal time accounting forPVdomain/IA64 TAKE2

[Isaku Yamahata <yamahata@xxxxxxxxxxxxx>]

On Tue, May 13, 2008 at 08:24:33PM +0900, Atsushi SAKAI wrote:
> The stolentick is composed of blocked, stolen and truely running time.
> The consider_steal_time() only treats above blocked and stolen value.
> So it does not need to add itm_delta more.

I understand what stolentick is.
But what about stolen and blocked?
local_cpu_data->itm_next can be past.
i.e. It can be smaller than ia64_get_itc() - local_cpu_data->itm_delta.


> 
> P.S.
> If you confuse the name of stolentick, please forgive me.
> 
> Thanks
> Atsushi SAKAI
> 
> 
> Isaku Yamahata <yamahata@xxxxxxxxxxxxx> wrote:
> 
> > On Fri, May 09, 2008 at 04:31:06PM +0900, Atsushi SAKAI wrote:
> > > 1)about new_itm  value.
> > > "new_itm" is set from local_cpu_data->itm_next
> > > (later I use this as itm_next) 
> > > at header part of timer_interrupt.
> > > 
> > > So it does not effect itm_next changes in
> > > consider_steal_time().
> > > 
> > > 2)The difference of following time 
> > > > > > ia64_get_itc() - (the itc of the last time 
> > > > > >                   the timer interrupt handler was invoked)
> > > 
> > > Every time should set next ITM like follows.
> > > local_cpu_data->itm_next(itm_next)+local_cpu_data->itm_delta(itm_delta).
> > > 
> > > So "guessed last itc" should be itm_next - itm_delta
> > > This itm_delta effect is already considered on stolentick++;
> > 
> > Really?
> > consider_steal_time()
> >         unsigned long delta_itm = 0, stolentick = 0;
> >         delta_itm += local_cpu_data->itm_delta * (stolen + blocked);
> >         local_cpu_data->itm_next = delta_itm + new_itm;
> > 
> > Shouldn't be delta_itm added one more local_cpu_data->itm_delta?
> > If consider_steal_time() returns 0, the while loop in timer_interrupt()
> > may add local_cpu_data->itm_delta more than once.
> > What's your assumption here?
> > 
> 
> 
> 
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-- 
yamahata

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