summaryrefslogtreecommitdiff
path: root/kernel/cgroup
diff options
context:
space:
mode:
authorWaiman Long <longman@redhat.com>2024-06-03 15:38:22 -0400
committerTejun Heo <tj@kernel.org>2024-06-03 09:47:11 -1000
commit1805c1729f52edaa021288473b09f9c7f74fb1ca (patch)
tree7b3572a78be0e3af4df570c58d36f67bbd0c2c75 /kernel/cgroup
parent018ee567def3b43f810aebf15221eef3858177b2 (diff)
cgroup/cpuset: Optimize isolated partition only generate_sched_domains() calls
If only isolated partitions are being created underneath the cgroup root, there will only be one sched domain with top_cpuset.effective_cpus. We can skip the unnecessary sched domains scanning code and save some cycles. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
Diffstat (limited to 'kernel/cgroup')
-rw-r--r--kernel/cgroup/cpuset.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index 315f8cbd6d35..f9b97f65e204 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -964,6 +964,7 @@ static int generate_sched_domains(cpumask_var_t **domains,
/* Special case for the 99% of systems with one, full, sched domain */
if (root_load_balance && !top_cpuset.nr_subparts) {
+single_root_domain:
ndoms = 1;
doms = alloc_sched_domains(ndoms);
if (!doms)
@@ -1022,6 +1023,13 @@ static int generate_sched_domains(cpumask_var_t **domains,
}
rcu_read_unlock();
+ /*
+ * If there are only isolated partitions underneath the cgroup root,
+ * we can optimize out unneeded sched domains scanning.
+ */
+ if (root_load_balance && (csn == 1))
+ goto single_root_domain;
+
for (i = 0; i < csn; i++)
csa[i]->pn = i;
ndoms = csn;