v5:
- Reapply on top of the latest upstream linux tree.
- Add a new fix patch for a cpuset bug found during testing.
- Add a patch to not update isolated_cpus when calling from CPU
hotplug. As a result, CPU hotplug won't need to call
housekeeping_update() at all and the corresponding wq deferral
patch is dropped.
v4:
- https://lore.kernel.org/lkml/[email protected]/
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 5 for details.
To fix this issue, the cpuset code is modified to not doing any
update to isolated_cpus when calling from CPU hotplug. In addition,
the housekeeping_update() call, when needed, is deferred to task_work
so that it can be called without holding a cpus_read_lock. A new top
level cpuset_top_mutex is also added to have more exclusion control.
With these changes in place, the cpuset test ran to completion with no
failure and no lockdep splat.
[1] https://lore.kernel.org/lkml/[email protected]/
Waiman Long (6):
cgroup/cpuset: Fix incorrect change to effective_xcpus in
partition_xcpus_del()
cgroup/cpuset: Clarify exclusion rules for cpuset internal variables
cgroup/cpuset: Set isolated_cpus_updating only if isolated_cpus is
changed
cgroup/cpuset: Don't update isolated_cpus from CPU hotplug
cgroup/cpuset: Call housekeeping_update() without holding
cpus_read_lock
cgroup/cpuset: Eliminate some duplicated rebuild_sched_domains() calls
kernel/cgroup/cpuset.c | 313 ++++++++++++++----
kernel/sched/isolation.c | 4 +-
kernel/time/timer_migration.c | 4 +-
.../selftests/cgroup/test_cpuset_prs.sh | 21 +-
4 files changed, 259 insertions(+), 83 deletions(-)
--
2.52.0
