v2:
- Change patch 1 to use workqueue instead of task run as it is a
per-cpu kthread that performs the cpuset shutdown and bringup work.
- Simplify and streamline some of the code.
After booting the latest cgroup for-next debug kernel with the latest
cgroup changes as well as Federic's "cpuset/isolation: Honour kthreads
preferred affinity" patch series [1] merged on top and running the
test-cpuset-prs.sh test, a circular locking dependency lockdep splat
was reported. See patch 2 for details.
The following changes are made to resolve this locking problem.
1) Deferring calling housekeeping_update() from CPU hotplug to workqueue
2) Release cpus_read_lock before calling housekeeping_update()
With these changes, the cpuset test ran to completion with no failure
and no lockdep splat.
[1] https://lore.kernel.org/lkml/[email protected]/
Waiman Long (2):
cgroup/cpuset: Defer housekeeping_update() call from CPU hotplug to
workqueue
cgroup/cpuset: Introduce a new top level cpuset_top_mutex
kernel/cgroup/cpuset.c | 124 ++++++++++++++----
kernel/sched/isolation.c | 4 +-
kernel/time/timer_migration.c | 3 +-
.../selftests/cgroup/test_cpuset_prs.sh | 13 +-
4 files changed, 107 insertions(+), 37 deletions(-)
--
2.52.0
