With the previous commit that eliminates the overlapping partition root corner cases in the hotplug code, the partition roots passed down to generate_sched_domains() should not have overlapping CPUs. Enable overlapping cpuset check for v2 and warn if that happens.
This patch also has the benefit of increasing test coverage of the new Union-Find cpuset merging code to cgroup v2.
Signed-off-by: Waiman Long longman@redhat.com --- kernel/cgroup/cpuset.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-)
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index e070e391d7a8..e34fd6108b06 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1127,25 +1127,27 @@ static int generate_sched_domains(cpumask_var_t **domains, if (root_load_balance && (csn == 1)) goto single_root_domain;
- if (!cgrpv2) { - for (i = 0; i < csn; i++) - uf_node_init(&csa[i]->node); - - /* Merge overlapping cpusets */ - for (i = 0; i < csn; i++) { - for (j = i + 1; j < csn; j++) { - if (cpusets_overlap(csa[i], csa[j])) - uf_union(&csa[i]->node, &csa[j]->node); + for (i = 0; i < csn; i++) + uf_node_init(&csa[i]->node); + + /* Merge overlapping cpusets */ + for (i = 0; i < csn; i++) { + for (j = i + 1; j < csn; j++) { + if (cpusets_overlap(csa[i], csa[j])) { + /* + * Cgroup v2 shouldn't pass down overlapping + * partition root cpusets. + */ + WARN_ON_ONCE(cgrpv2); + uf_union(&csa[i]->node, &csa[j]->node); } } + }
- /* Count the total number of domains */ - for (i = 0; i < csn; i++) { - if (uf_find(&csa[i]->node) == &csa[i]->node) - ndoms++; - } - } else { - ndoms = csn; + /* Count the total number of domains */ + for (i = 0; i < csn; i++) { + if (uf_find(&csa[i]->node) == &csa[i]->node) + ndoms++; }
/*