On 07/05/2020 23:15, Valentin Schneider wrote:
>
> On 07/05/20 19:05, John Mathew wrote:
[...]
> It would also be an opportunity to have one place to (at least briefly)
> describe what the different sched classes do wrt capacity asymmetry - CFS
> does one thing, RT now does one thing (see Qais' work), and DL will
> hopefully soon follow (see Dietmar's work).
>
> I'd be happy to contribute (some of) that, if it can be deemed useful (I
> personally think it might).
I like the idea.
Essentially all the code which is guarded by the 'if
(static_branch_unlikely(&sched_asym_cpucapacity)' condition or which
sets it during bring-up.
* 'Cpu capacity < SCHED_LOAD_SCALE for non-big' CPUs setting during
bringup (necessary dt binding, CPUfreq influence)
* CFS capacity awareness:
* wakeup - select_idle_capacity() (replaced wake_cap() & slow path to
cover DynamIQ and classical big.LITTLE)
* load_balance - misfit handling
* RT & DL capacity awareness
* ... & the relation to EAS (Documentation/scheduler/sched-energy.rst)
This is what we referred to (at least internally) as CAS (Capacity-Aware
Scheduling).
