Re: [BUG] Corrupted SCHED_DEADLINE bandwidth with cpusets

[Steven Rostedt]

On Wed, 3 Feb 2016 13:55:50 -0500
Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:

>  # grep dl /proc/sched_debug
> dl_rq[0]:
>   .dl_nr_running                 : 0
>   .dl_bw->bw                     : 996147
>   .dl_bw->total_bw               : -104857
> dl_rq[1]:
>   .dl_nr_running                 : 0
>   .dl_bw->bw                     : 996147
>   .dl_bw->total_bw               : -104857
> dl_rq[2]:
>   .dl_nr_running                 : 0
>   .dl_bw->bw                     : 996147
>   .dl_bw->total_bw               : -104857
> dl_rq[3]:
>   .dl_nr_running                 : 0
>   .dl_bw->bw                     : 996147
>   .dl_bw->total_bw               : -104857
> dl_rq[4]:
>   .dl_nr_running                 : 0
>   .dl_bw->bw                     : 996147
>   .dl_bw->total_bw               : -104857
> dl_rq[5]:
>   .dl_nr_running                 : 0
>   .dl_bw->bw                     : 996147
>   .dl_bw->total_bw               : -104857
> dl_rq[6]:
>   .dl_nr_running                 : 0
>   .dl_bw->bw                     : 996147
>   .dl_bw->total_bw               : -104857
> dl_rq[7]:
>   .dl_nr_running                 : 0
>   .dl_bw->bw                     : 996147
>   .dl_bw->total_bw               : -104857
> 
> They all went negative!
> 
> Not good, but we can recover...

Even though we can recover, I'm betting we can easily overcommit
deadline tasks here. It probably wouldn't be too hard to come up with a
test case that does so.

-- Steve