Re: [PATCH 0/7] CPU controller - V1

Srivatsa Vaddagiri
2006-08-21T12:49:15Z

On Mon, Aug 21, 2006 at 10:42:40AM +0000, Mike Galbraith wrote:
> WRT interactivity: Looking at try_to_wake_up(), it appears that wake-up
> of a high priority group-a task will not result in preemption of a lower
> priority current group-b task. True?

I dont think it is true. The definition of TASK_PREEMPTS_CURR() is
unchanged with these patches. Also group priority is linked to the
highest priority task it has. As a result, the high-priority group-a
task should preempt the low priority group-b task.

This is unless group-a has currently run out of its bandwidth and is sitting in
the expired queue (which is something that the TASK_PREEMPTS_CURR()
can be optimized to check for).

--
Regards,
vatsa