Re: [PATCH] percpu-refcount: relax limit on percpu_ref_reinit()

From: jianchao.wang
Date: Tue Sep 11 2018 - 10:13:38 EST


Hi tejun

On 09/11/2018 09:44 PM, Tejun Heo wrote:
> Hello,
>
> On Tue, Sep 11, 2018 at 12:40:36PM +0800, jianchao.wang wrote:
>> (long)(sum (every cpu's refcounter)) + atomic refcounter
>>
>> and when switch to atomic mode, there could be value left in atomic refcounter.
>> then the unsigned long percpu refcounter cound be decreased from 0.
>
> It can always do that. Imagine a task getting a ref on one cpu,
> migrating and putting it on another. The only thing which matters is
> that the sum of everything adds upto what it should be.
>

Thanks for your kindly response.
I have got the point here.

Thanks
Jianchao