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 task work 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 task_work cgroup/cpuset: Introduce a new top level isolcpus_update_mutex kernel/cgroup/cpuset.c | 124 ++++++++++++++---- kernel/sched/isolation.c | 4 +- kernel/time/timer_migration.c | 3 +- .../selftests/cgroup/test_cpuset_prs.sh | 9 ++ 4 files changed, 111 insertions(+), 29 deletions(-) -- 2.52.0
