Re: [BUG]: Crash with CONFIG_FAIR_CGROUP_SCHED=y

["Dmitry Adamushko" <dmitry.adamushko@gmail.com>]

Hi Srivatsa,

> [ ... ]
> --
>
> current task is not present in its runqueue in case of sched_fair class
> tasks. Take care of this fact in rt_mutex_setprio(),
> sched_setscheduler() and sched_move_task() routines.
>
> Signed-off-by : Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
>
>
> ---
>  kernel/sched.c |   45 +++++++++++++++++++++++++--------------------
>  1 files changed, 25 insertions(+), 20 deletions(-)
>
> Index: current/kernel/sched.c
> ===================================================================
> --- current.orig/kernel/sched.c
> +++ current/kernel/sched.c
> @@ -3986,11 +3986,13 @@ void rt_mutex_setprio(struct task_struct
>         oldprio = p->prio;
>         on_rq = p->se.on_rq;
>         running = task_running(rq, p);
> -       if (on_rq) {
> +       if (on_rq)
>                 dequeue_task(rq, p, 0);
> -               if (running)
> -                       p->sched_class->put_prev_task(rq, p);
> -       }
> +       /* current task is not kept in its runqueue in case of sched_fair class.
> +        * Hence we need the 'on_rq?' and 'running?' tests to be separate.

Humm... the 'current' is not kept within the tree but
current->se.on_rq is supposed to be '1' ,
so the old code looks ok to me (at least for the 'leaf' elements).

Maybe you were able to get more useful oops on your site?


> --
> Regards,
> vatsa
>

-- 
Best regards,
Dmitry Adamushko