Re: [RFC PATCH v2 0/3] sched/fair: introduce new scheduler group type group_parked

[Tobias Huschle]

On 18/02/2025 06:58, Shrikanth Hegde wrote:
[...]
> > There are a couple of issues and corner cases which need further
> > considerations:
> > - rt & dl:      Realtime and deadline scheduling require some additional
> >                  attention.
>
> I think we need to address atleast rt, there would be some non percpu 
> kworker threads which need to move out of parked cpus.

Yea, sounds reasonable. Would probably make sense to go next for that one.

> > - ext:          Probably affected as well. Needs some conceptional
> >                  thoughts first.
> > - raciness:     Right now, there are no synchronization efforts. It needs
> >                  to be considered whether those might be necessary or if
> >                  it is alright that the parked-state of a CPU might 
> > change
> >                  during load-balancing.
> >
> > Patches apply to tip:sched/core
> >
> > The s390 patch serves as a simplified implementation example.
>
>
> Gave it a try on powerpc with the debugfs file. it works for 
> sched_normal tasks.

That's great to hear!

> > Tobias Huschle (3):
> >    sched/fair: introduce new scheduler group type group_parked
> >    sched/fair: adapt scheduler group weight and capacity for parked CPUs
> >    s390/topology: Add initial implementation for selection of parked CPUs
> >
> >   arch/s390/include/asm/smp.h    |   2 +
> >   arch/s390/kernel/smp.c         |   5 ++
> >   include/linux/sched/topology.h |  19 ++++++
> >   kernel/sched/core.c            |  13 ++++-
> >   kernel/sched/fair.c            | 104 ++++++++++++++++++++++++++++-----
> >   kernel/sched/syscalls.c        |   3 +
> >   6 files changed, 130 insertions(+), 16 deletions(-)