Re: PATCH: Fix race in cpu_down (hotplug cpu)

Srivatsa Vaddagiri
2005-09-19T05:29:08Z

On Mon, Sep 19, 2005 at 03:23:01PM +1000, Nigel Cunningham wrote:
> Maybe I'm just an ignoramus, but I was thinking (without being a
> scheduler expert at all) that if the idle thread was already running,
> trying to set it up to run next might possibly have zero effect. I've

sched_idle_next actually adds the idle task to its runqueue (normally
it is not present in a runqueue while running) and as well changes its
priority/policy. So it does have *some* effect!

> added a bit of debugging code to try and see in better detail what's
> happening.

Could you elaborate (with some stack traces maybe) on the deadlock you are
seeing during resume? Maybe that can throw some light.

--

Thanks and Regards,
Srivatsa Vaddagiri,
Linux Technology Center,
IBM Software Labs,
Bangalore, INDIA - 560017