As discussed in the LKML thread [1], the asynchronous nature of cpuset hotplug handling code is causing problem with RCU testing. With recent changes in the way locking is being handled in the cpuset code, it is now possible to make the cpuset hotplug code synchronous again without major changes.
This series enables the hotplug code to call directly into cpuset hotplug core without indirection with the exception of the special case of v1 cpuset becoming empty still being handled indirectly with workqueue.
A new simple test case was also written to test this special v1 cpuset case. The test_cpuset_prs.sh script was also run with LOCKDEP on to verify that there is no regression.
[1] https://lore.kernel.org/lkml/ZgYikMb5kZ7rxPp6@slm.duckdns.org/
Waiman Long (2): cgroup/cpuset: Make cpuset hotplug processing synchronous cgroup/cpuset: Add test_cpuset_v1_hp.sh
include/linux/cpuset.h | 3 - kernel/cgroup/cpuset.c | 131 +++++++----------- kernel/cpu.c | 48 ------- kernel/power/process.c | 2 - tools/testing/selftests/cgroup/Makefile | 2 +- .../selftests/cgroup/test_cpuset_v1_hp.sh | 40 ++++++ 6 files changed, 88 insertions(+), 138 deletions(-) create mode 100755 tools/testing/selftests/cgroup/test_cpuset_v1_hp.sh