Commit-ID: f220242af98a5248209426f36d93226c3e0f2391
Gitweb: http://git.kernel.org/tip/f220242af98a5248209426f36d93226c3e0f2391
Author: Paul E. McKenney <paul.mckenney@xxxxxxxxxx>
AuthorDate: Sat, 3 Dec 2011 15:09:28 -0800
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Sun, 11 Dec 2011 10:32:21 -0800
rcu: Make rcutorture test for hotpluggability before offlining CPUs
The rcutorture test now can automatically exercise CPU hotplug and
collect success statistics, which can be correlated with other rcutorture
activity. This permits rcutorture to completely exercise RCU regardless
of what sort of userspace and filesystem layout is in use. Unfortunately,
rcutorture is happy to attempt to offline CPUs that cannot be offlined,
for example, CPU 0 in both the x86 and ARM architectures. Although this
allows rcutorture testing to proceed normally, it confounds attempts at
error analysis due to the resulting flood of spurious CPU-hotplug errors.
Therefore, this commit uses the new cpu_is_hotpluggable() function to
avoid attempting to offline CPUs that are not hotpluggable, which in
turn avoids spurious CPU-hotplug errors.
Signed-off-by: Paul E. McKenney <paul.mckenney@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
kernel/rcutorture.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index 1e422ae..186ead9 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -1388,7 +1388,7 @@ rcu_torture_onoff(void *arg)
WARN_ON(maxcpu < 0);
while (!kthread_should_stop()) {
cpu = (rcu_random(&rand) >> 4) % (maxcpu + 1);
- if (cpu_online(cpu)) {
+ if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) {
if (verbose)
printk(KERN_ALERT "%s" TORTURE_FLAG
"rcu_torture_onoff task: offlining %d\n",
@@ -1402,7 +1402,7 @@ rcu_torture_onoff(void *arg)
torture_type, cpu);
n_offline_successes++;
}
- } else {
+ } else if (cpu_is_hotpluggable(cpu)) {
if (verbose)
printk(KERN_ALERT "%s" TORTURE_FLAG
"rcu_torture_onoff task: onlining %d\n",
--
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