sched: fix: don't take a mutex from interrupt context

print_cfs_stats is callable from interrupt context (sysrq), hence it should
not take mutexes. Change it to use RCU since the task group data is RCU
freed anyway.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 2 insertions, 2 deletions

diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c
index 1b3b40ad7c54..45ff4e9411e0 100644
--- a/kernel/sched_fair.c
+++ b/kernel/sched_fair.c
@@ -1434,9 +1434,9 @@ static void print_cfs_stats(struct seq_file *m, int cpu)
 #ifdef CONFIG_FAIR_GROUP_SCHED
         print_cfs_rq(m, cpu, &cpu_rq(cpu)->cfs);
 #endif
-        lock_task_group_list();
+        rcu_read_lock();
         for_each_leaf_cfs_rq(cpu_rq(cpu), cfs_rq)
                 print_cfs_rq(m, cpu, cfs_rq);
-        unlock_task_group_list();
+        rcu_read_unlock();
 }
 #endif