rcu: Make rcutorture give diagnostics if CPU offline fails
This commit causes rcutorture to print the errno if cpu_down() fails
when the rcutorture "verbose" module parameter is specified.
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index aaa7b9f..9900f56 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -1502,6 +1502,7 @@
unsigned long delta;
int maxcpu = -1;
DEFINE_RCU_RANDOM(rand);
+ int ret;
unsigned long starttime;
VERBOSE_PRINTK_STRING("rcu_torture_onoff task started");
@@ -1522,7 +1523,13 @@
torture_type, cpu);
starttime = jiffies;
n_offline_attempts++;
- if (cpu_down(cpu) == 0) {
+ ret = cpu_down(cpu);
+ if (ret) {
+ if (verbose)
+ pr_alert("%s" TORTURE_FLAG
+ "rcu_torture_onoff task: offline %d failed: errno %d\n",
+ torture_type, cpu, ret);
+ } else {
if (verbose)
pr_alert("%s" TORTURE_FLAG
"rcu_torture_onoff task: offlined %d\n",