Re: [RFC PATCH 24/24] sched/time: Introduce CLOCK_THREAD_DVFS_ID

Peter Zijlstra
2024-08-02T11:30:08Z

On Mon, Jul 29, 2024 at 09:53:17AM +0200, Juri Lelli wrote:
> Hi Peter,
>
> On 27/07/24 12:27, Peter Zijlstra wrote:
> > In order to measure thread time in a DVFS world, introduce
> > CLOCK_THREAD_DVFS_ID -- a copy of CLOCK_THREAD_CPUTIME_ID that slows
> > down with both DVFS scaling and CPU capacity.
> >
> > The clock does *NOT* support setting timers.
> >
> > Useful for both SCHED_DEADLINE and the newly introduced
> > sched_attr::sched_runtime usage for SCHED_NORMAL.
>
> Just so I'm sure I understand, this would be useful for estimating the
> runtime needs of a (also DEADLINE) task when DVFS is enabled, right?

Correct, DVFS or biggie-smalls CPUs with mixed capacities.