Re: [PATCH] workqueue: clear workers of a pool after the CPU is offline

[Lai Jiangshan <laijs@cn.fujitsu.com>]

On 07/26/2013 11:07 AM, Tejun Heo wrote:
> Hello,
> 
> On Fri, Jul 26, 2013 at 10:13:25AM +0800, Lai Jiangshan wrote:
>>> Hmmm... if I'm not confused, now the cpu pools just behave like a
>>> normal unbound pool when the cpu goes down,
>>
>> cpu pools are always referenced, they don't behave like unbound pool.
> 
> Yeah sure, they don't get destroyed but pool management functions the
> same.
> 
>>> which means that the idle
>>> cpu workers will exit once idle timeout is reached, right? 
>>
>> No, no code to force the cpu workers quit currently.
>> you can just offline a cpu to see what happened to the workers.
> 
> Hmmm?  The idle timer thing doesn't work?  Why?
> 

any worker can't kill itself.
managers always tries to leave 2 workers.

so the workers of the offline cpu pool can't be totally destroyed.

(In old days, we also have idle timer, but the last workers are killed by trustee_thread())