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

From: Srivatsa Vaddagiri
Date: Mon Sep 19 2005 - 00:29:27 EST

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
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