Re: [bug report] resctrl high memory comsumption

[Fenghua Yu]

On Wed, Jan 08, 2020 at 09:07:41AM -0800, Shakeel Butt wrote:
> Hi,
> 
> Recently we had a bug in the system software writing the same pids to
> the tasks file of resctrl group multiple times. The resctrl code
> allocates "struct task_move_callback" for each such write and call
> task_work_add() for that task to handle it on return to user-space
> without checking if such request already exist for that particular
> task. The issue arises for long sleeping tasks which has thousands for
> such request queued to be handled. On our production, we notice
> thousands of tasks having thousands of such requests and taking GiBs
> of memory for "struct task_move_callback". I am not very familiar with
> the code to judge if task_work_cancel() is the right approach or just
> checking closid/rmid before doing task_work_add().
> 

Thank you for reporting the issue, Shakeel!

Could you please check if the following patch fixes the issue?