sched/deadline: cpuset task acceptance review

While surveying the properties of the SCHED_DEADLINE, Marco Perronet found some inconsistencies in the acceptance of DL threads on cpuset. More precisely, regarding the acceptance of treads with arbitrary affinity. He contacted me, and while doing the investigation, we found yet other potential issues addressed in this patch series.

Each patch has a more in-depth explanation, including ways to reproduce the problem.

Daniel Bristot de Oliveira (6):
sched/deadline: Consolidate the SCHED_DL task_can_attach() check on
its own function
sched/deadline: Inform dl_task_can_attach() if the cpuset is exclusive sched/deadline: Allow DL tasks on empty (cgroup v2) cpusets sched/deadline: Block DL tasks on non-exclusive cpuset if bandwitdh
control is enable
sched/deadline: Add helpers to get the correct root domain/span/dl_bw sched/deadline: Fixes cpu/rd/dl_bw references for suspended tasks

 include/linux/sched.h   |  2 +-
 kernel/cgroup/cpuset.c  |  5 ++++-
 kernel/sched/core.c     | 13 ++++++------
 kernel/sched/deadline.c | 28 ++++++++++++++++++++++---
 kernel/sched/sched.h    | 45 ++++++++++++++++++++++++++++++++++++++++-
 5 files changed, 80 insertions(+), 13 deletions(-)

2.29.2