Re: [PATCH 7/9] sched: Add migrate_disable()

[peterz]

On Wed, Sep 23, 2020 at 10:31:10AM +0200, Thomas Gleixner wrote:
>    In practice migrate disable could be taken into account on placement
>    decisions, but yes we don't have anything like that at the moment.

I think at the very least we should do some of that.

The premise is wanting to run the M highest priority tasks, when a CPU
drops priority, it tries to PULL a higher priority task towards itself.
If this PULL selects a migrate_disable() tasks, it means the task is in
the M highest prio tasks.

Since obviously that task cannot get pulled, we should then pull the
current running task of that CPU, this would then allow the
migrate_disable() task to resume execution.

I'll go try and cook up something along those lines...