sched/walt: Accounting for number of irqs pending on each core

[firefly-linux-kernel-4.4.55.git] / kernel / cgroup.c

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 8191a95f995270fe226c18b2cfb1479664411ce5..f53e61f95b5500cfad27527956f3ea971dd42411 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -5380,6 +5380,12 @@ int __init cgroup_init(void)
        BUG_ON(cgroup_init_cftypes(NULL, cgroup_dfl_base_files));
        BUG_ON(cgroup_init_cftypes(NULL, cgroup_legacy_base_files));
 
+       /*
+        * The latency of the synchronize_sched() is too high for cgroups,
+        * avoid it at the cost of forcing all readers into the slow path.
+        */
+       rcu_sync_enter_start(&cgroup_threadgroup_rwsem.rss);
+
        mutex_lock(&cgroup_mutex);
 
        /* Add init_css_set to the hash table */