lkml.org 
[lkml]   [2018]   [Jul]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH 07/11] cpufreq/schedutil: take into account interrupt
On Fri, 6 Jul 2018 at 11:14, Peter Zijlstra <peterz@infradead.org> wrote:
>
> On Fri, Jul 06, 2018 at 11:30:33AM +0530, Viresh Kumar wrote:
> > On 28-06-18, 17:45, Vincent Guittot wrote:
> > > The time spent under interrupt can be significant but it is not reflected
> > > in the utilization of CPU when deciding to choose an OPP. Now that we have
> > > access to this metric, schedutil can take it into account when selecting
> > > the OPP for a CPU.
> > > rqs utilization don't see the time spend under interrupt context and report
> > > their value in the normal context time window. We need to compensate this when
> > > adding interrupt utilization
> > >
> > > The CPU utilization is :
> > > irq util_avg + (1 - irq util_avg / max capacity ) * /Sum rq util_avg
> > >
> > > A test with iperf on hikey (octo arm64) gives:
> > > iperf -c server_address -r -t 5
> > >
> > > w/o patch w/ patch
> > > Tx 276 Mbits/sec 304 Mbits/sec +10%
> > > Rx 299 Mbits/sec 328 Mbits/sec +09%
> > >
> > > 8 iterations
> > > stdev is lower than 1%
> > > Only WFI idle state is enable (shallowest diel state)
>
> Also s/diel/idle/
>
> > > + /*
> > > + * Interrupt time is not seen by rqs utilization nso we can compare
> >
> > nso ?
> >
> > > + * them with the CPU capacity
> > > + */
>
> Already fixed ;-)

Thanks

\
 
 \ /
  Last update: 2018-07-06 11:23    [W:0.055 / U:1.868 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site