The isolated_cpus_can_update() and prstate_housekeeping_conflict() are
checking different aspects of upcoming cpumask changes that may conflict
with the current setting of the housekeeping cpumasks. There are places
where both are called together. There are also places where only one
of them is called. That inconsistency can contribute to missing check
where invalid cpumask changes may be allowed to move forward.
Fix that by consolidating isolated_cpus_can_update() into
prstate_housekeeping_conflict() and call prstate_housekeeping_conflict()
in all the places where either one of them or both are called. The
exception is the validate_partition() function where the
prstate_housekeeping_conflict() call is removed. It is because
validate_partition() is called only from partition_cpus_change()
where prstate_housekeeping_conflict() will be called from either
remote_cpus_update() or update_parent_effective_cpumask() with
partcmd_update if not for partition invalidatation or disablement.
Now prstate_housekeeping_conflict() will be called in the following
locations:
- when a partition is enabled in remote_partition_enable() or in
update_parent_effective_cpumask() with partcmd_enable*.
- when a cpumask is updated in remote_cpus_update() or in
update_parent_effective_cpumask() with partcmd_update.
- when a partition state changes from root to isolated or vice versa
in update_prstate().
Fixes: 4a74e418881f ("cgroup/cpuset: Check partition conflict with housekeeping
setup")
Fixes: 103b08709e8a ("cgroup/cpuset: Fail if isolated and nohz_full don't leave any
housekeeping")
Signed-off-by: Waiman Long <[email protected]>
---
kernel/cgroup/cpuset.c | 123 +++++++++++++++++------------------------
1 file changed, 52 insertions(+), 71 deletions(-)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 0ebba2d646c3..f3cebb277a68 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -1353,65 +1353,62 @@ static void partition_xcpus_del(int old_prs, struct
cpuset *parent,
}
/*
- * isolated_cpus_can_update - check for isolated & nohz_full conflicts
- * @add_cpus: cpu mask for cpus that are going to be isolated
- * @del_cpus: cpu mask for cpus that are no longer isolated, can be NULL
- * Return: false if there is conflict, true otherwise
- *
- * If nohz_full is enabled and we have isolated CPUs, their combination must
- * still leave housekeeping CPUs.
+ * prstate_housekeeping_conflict - check for partition & housekeeping conflicts
+ * @new_prs: new partition root state to be checked
+ * @parent_prs: Parent partition root state
+ * @add_cpus: additional CPUs to be added to current cpuset
+ * @del_cpus: CPUs to be removed from current cpuset, can be NULL
+ * Return: true if there is conflict, false otherwise
*
- * TBD: Should consider merging this function into
- * prstate_housekeeping_conflict().
+ * There are two different housekeeping conflicts to be checked:
+ * 1) If new_prs is PRS_ROOT, none of the @add_cpus can be a boot-time isolated
+ * CPU. IOW, the whole @add_cpus must be a subset of HK_TYPE_DOMAIN_BOOT.
+ * 2) If nohz_full is enabled and we have isolated CPUs, their combination must
+ * still leave housekeeping CPUs. This check is only needed if new_prs
+ * differs from parent_prs and one of them is PRS_ISOLATED.
*/
-static bool isolated_cpus_can_update(struct cpumask *add_cpus,
- struct cpumask *del_cpus)
+static bool prstate_housekeeping_conflict(int new_prs, int parent_prs,
+ struct cpumask *add_cpus,
+ struct cpumask *del_cpus)
{
cpumask_var_t full_hk_cpus;
- int res = true;
+ int res;
- if (!housekeeping_enabled(HK_TYPE_KERNEL_NOISE))
+ if (housekeeping_enabled(HK_TYPE_DOMAIN_BOOT) && (new_prs == PRS_ROOT)
&&
+ !cpumask_subset(add_cpus,
housekeeping_cpumask(HK_TYPE_DOMAIN_BOOT)))
return true;
- if (del_cpus && cpumask_weight_and(del_cpus,
- housekeeping_cpumask(HK_TYPE_KERNEL_NOISE)))
- return true;
+ if (!housekeeping_enabled(HK_TYPE_KERNEL_NOISE) ||
+ (new_prs == parent_prs) ||
+ (!del_cpus && (new_prs != PRS_ISOLATED)) ||
+ ((new_prs != PRS_ISOLATED) && (parent_prs != PRS_ISOLATED)))
+ return false;
