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authorPaul E. McKenney <paul.mckenney@linaro.org>2012-01-17 14:36:51 -0800
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2012-02-21 09:03:50 -0800
commit9b9ec9b90ef481e182927989963274dc2697f9a6 (patch)
tree977b0fc115b279c25de3200a6bd4d67f1eff83c8 /kernel/rcutorture.c
parenta858af2875fb291d0f4b0a4419fefbf03c2379c0 (diff)
downloadlinux-9b9ec9b90ef481e182927989963274dc2697f9a6.tar.bz2
rcutorture: Permit holding off CPU-hotplug operations during boot
When rcutorture is started automatically at boot time, it might well also start CPU-hotplug operations at that time, which might not be desirable. This commit therefore adds an rcutorture parameter that allows CPU-hotplug operations to be held off for the specified number of seconds after the start of boot. Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcutorture.c')
-rw-r--r--kernel/rcutorture.c12
1 files changed, 10 insertions, 2 deletions
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index a52b3217c160..2914cafe171b 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -65,6 +65,7 @@ static int fqs_duration; /* Duration of bursts (us), 0 to disable. */
static int fqs_holdoff; /* Hold time within burst (us). */
static int fqs_stutter = 3; /* Wait time between bursts (s). */
static int onoff_interval; /* Wait time between CPU hotplugs, 0=disable. */
+static int onoff_holdoff; /* Seconds after boot before CPU hotplugs. */
static int shutdown_secs; /* Shutdown time (s). <=0 for no shutdown. */
static int test_boost = 1; /* Test RCU prio boost: 0=no, 1=maybe, 2=yes. */
static int test_boost_interval = 7; /* Interval between boost tests, seconds. */
@@ -95,6 +96,8 @@ module_param(fqs_stutter, int, 0444);
MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)");
module_param(onoff_interval, int, 0444);
MODULE_PARM_DESC(onoff_interval, "Time between CPU hotplugs (s), 0=disable");
+module_param(onoff_holdoff, int, 0444);
+MODULE_PARM_DESC(onoff_holdoff, "Time after boot before CPU hotplugs (s)");
module_param(shutdown_secs, int, 0444);
MODULE_PARM_DESC(shutdown_secs, "Shutdown time (s), zero to disable.");
module_param(test_boost, int, 0444);
@@ -1300,13 +1303,13 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, char *tag)
"fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
"test_boost=%d/%d test_boost_interval=%d "
"test_boost_duration=%d shutdown_secs=%d "
- "onoff_interval=%d\n",
+ "onoff_interval=%d onoff_holdoff=%d\n",
torture_type, tag, nrealreaders, nfakewriters,
stat_interval, verbose, test_no_idle_hz, shuffle_interval,
stutter, irqreader, fqs_duration, fqs_holdoff, fqs_stutter,
test_boost, cur_ops->can_boost,
test_boost_interval, test_boost_duration, shutdown_secs,
- onoff_interval);
+ onoff_interval, onoff_holdoff);
}
static struct notifier_block rcutorture_shutdown_nb = {
@@ -1410,6 +1413,11 @@ rcu_torture_onoff(void *arg)
for_each_online_cpu(cpu)
maxcpu = cpu;
WARN_ON(maxcpu < 0);
+ if (onoff_holdoff > 0) {
+ VERBOSE_PRINTK_STRING("rcu_torture_onoff begin holdoff");
+ schedule_timeout_interruptible(onoff_holdoff * HZ);
+ VERBOSE_PRINTK_STRING("rcu_torture_onoff end holdoff");
+ }
while (!kthread_should_stop()) {
cpu = (rcu_random(&rand) >> 4) % (maxcpu + 1);
if (cpu_online(cpu) && cpu_is_hotpluggable(cpu)) {