rcu: Don't scan root rcu_node structure for stalled tasks

Now that blocked tasks are no longer migrated to the root rcu_node
structure, there is no need to scan the root rcu_node structure for
blocked tasks stalling the current grace period.  This commit therefore
removes this scan.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>

diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 24d3c67..4ed2c28 100644 (file)
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1107,15 +1107,6 @@ static void print_other_cpu_stall(struct rcu_state *rsp)
                raw_spin_unlock_irqrestore(&rnp->lock, flags);
        }
 
-       /*
-        * Now rat on any tasks that got kicked up to the root rcu_node
-        * due to CPU offlining.
-        */
-       rnp = rcu_get_root(rsp);
-       raw_spin_lock_irqsave(&rnp->lock, flags);
-       ndetected += rcu_print_task_stall(rnp);
-       raw_spin_unlock_irqrestore(&rnp->lock, flags);
-
        print_cpu_stall_info_end();
        for_each_possible_cpu(cpu)
                totqlen += per_cpu_ptr(rsp->rda, cpu)->qlen;