When a CFS task that was boosted by a SCHED_DEADLINE
task boosts another CFS task (nested priority inheritance),
Kernel panic is observed.
Fixing priority inheritance changes the way how sched_deadline
attributes are being inherited from original donor task.

Additional supporting patches are added to fix throttling of
boosted tasks.

Daniel Bristot de Oliveira (1):
  sched/deadline: Unthrottle PI boosted threads while enqueuing

Lucas Stach (1):
  sched/deadline: Fix stale throttling on de-/boosted tasks

Juri Lelli (1):
  sched/deadline: Fix priority inheritance with multiple scheduling
    classes

Hui Su (1):
  kernel/sched: Remove dl_boosted flag comment

 include/linux/sched.h   |  13 ++--
 kernel/sched/core.c     |  11 ++--
 kernel/sched/deadline.c | 131 +++++++++++++++++++++++++---------------
 3 files changed, 96 insertions(+), 59 deletions(-)

-- 
2.34.1

On Mon, Aug 22, 2022 at 01:13:44PM +0530, Ankit Jain wrote:
> When a CFS task that was boosted by a SCHED_DEADLINE
> task boosts another CFS task (nested priority inheritance),
> Kernel panic is observed.
> Fixing priority inheritance changes the way how sched_deadline
> attributes are being inherited from original donor task.
> 
> Additional supporting patches are added to fix throttling of
> boosted tasks.
> 
> Daniel Bristot de Oliveira (1):
>   sched/deadline: Unthrottle PI boosted threads while enqueuing
> 
> Lucas Stach (1):
>   sched/deadline: Fix stale throttling on de-/boosted tasks
> 
> Juri Lelli (1):
>   sched/deadline: Fix priority inheritance with multiple scheduling
>     classes
> 
> Hui Su (1):
>   kernel/sched: Remove dl_boosted flag comment
> 
>  include/linux/sched.h   |  13 ++--
>  kernel/sched/core.c     |  11 ++--
>  kernel/sched/deadline.c | 131 +++++++++++++++++++++++++---------------
>  3 files changed, 96 insertions(+), 59 deletions(-)
> 
> -- 
> 2.34.1
> 

Both sets of backports now queued up, thanks.

greg k-h