[PATCH tip/core/rcu 5/5] rcu: Make rcutorture emit online failures if verbose

["Paul E. McKenney" <paulmck@linux.vnet.ibm.com>]

From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>

Although rcutorture counts CPU-hotplug online failures, it does
not explicitly record which CPUs were having trouble coming online.
This commit therefore emits a console message when online failure occurs.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
---
 kernel/rcutorture.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 7d42d13..15bec39 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -1437,7 +1437,13 @@ rcu_torture_onoff(void *arg)
 					 torture_type, cpu);
 			starttime = jiffies;
 			n_online_attempts++;
-			if (cpu_up(cpu) == 0) {
+			ret = cpu_up(cpu);
+			if (ret != 0) {
+				if (verbose)
+					pr_alert("%s" TORTURE_FLAG
+						 "rcu_torture_onoff task: online %d failed: errno %d\n",
+						 torture_type, cpu, ret);
+			} else {
 				if (verbose)
 					pr_alert("%s" TORTURE_FLAG
 						 "rcu_torture_onoff task: onlined %d\n",
-- 
1.8.1.5