Re: [RFC PATCH v2 09/17] cgroup: Keep accurate count of tasks in each css_set

[Waiman Long]

On 05/17/2017 05:40 PM, Tejun Heo wrote:
> Hello,
>
> On Mon, May 15, 2017 at 09:34:08AM -0400, Waiman Long wrote:
>> The reference count in the css_set data structure was used as a
>> proxy of the number of tasks attached to that css_set. However, that
>> count is actually not an accurate measure especially with thread mode
>> support. So a new variable task_count is added to the css_set to keep
>> track of the actual task count. This new variable is protected by
>> the css_set_lock. Functions that require the actual task count are
>> updated to use the new variable.
>>
>> Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
> Looks good.  We probably should replace css_set_populated() to use
> this too.
>
> Thanks.
>
Yes, you are right. css_set_populated() can be replaced with a check on
the task_count.

Regards,
Longman