Commit-ID: d5f546d834ddc44539651e9955eb3577b0a3eb8b
Gitweb: http://git.kernel.org/tip/d5f546d834ddc44539651e9955eb3577b0a3eb8b
Author: Paul E. McKenney <paul.mckenney@xxxxxxxxxx>
AuthorDate: Fri, 4 Nov 2011 11:44:12 -0700
Committer: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
CommitDate: Sun, 11 Dec 2011 10:31:46 -0800
rcu: Add rcutorture system-shutdown capability
Although it is easy to run rcutorture tests under KVM, there is currently
no nice way to run such a test for a fixed time period, collect all of
the rcutorture data, and then shut the system down cleanly. This commit
therefore adds an rcutorture module parameter named "shutdown_secs" that
specified the run duration in seconds, after which rcutorture terminates
the test and powers the system down. The default value for "shutdown_secs"
is zero, which disables shutdown.
Signed-off-by: Paul E. McKenney <paul.mckenney@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
Documentation/RCU/torture.txt | 5 +++
kernel/rcutorture.c | 68 ++++++++++++++++++++++++++++++++++++++--
2 files changed, 69 insertions(+), 4 deletions(-)
diff --git a/Documentation/RCU/torture.txt b/Documentation/RCU/torture.txt
index 783d6c1..af40929 100644
--- a/Documentation/RCU/torture.txt
+++ b/Documentation/RCU/torture.txt
@@ -66,6 +66,11 @@ shuffle_interval
to a particular subset of the CPUs, defaults to 3 seconds.
Used in conjunction with test_no_idle_hz.
+shutdown_secs The number of seconds to run the test before terminating
+ the test and powering off the system. The default is
+ zero, which disables test termination and system shutdown.
+ This capability is useful for automated testing.
+
stat_interval The number of seconds between output of torture
statistics (via printk()). Regardless of the interval,
statistics are printed when the module is unloaded.
diff --git a/kernel/rcutorture.c b/kernel/rcutorture.c
index df35228..ce84091 100644
--- a/kernel/rcutorture.c
+++ b/kernel/rcutorture.c
@@ -61,9 +61,10 @@ static int test_no_idle_hz; /* Test RCU's support for tickless idle CPUs. */
static int shuffle_interval = 3; /* Interval between shuffles (in sec)*/
static int stutter = 5; /* Start/stop testing interval (in sec) */
static int irqreader = 1; /* RCU readers from irq (timers). */
-static int fqs_duration = 0; /* Duration of bursts (us), 0 to disable. */
-static int fqs_holdoff = 0; /* Hold time within burst (us). */
+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 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. */
static int test_boost_duration = 4; /* Duration of each boost test, seconds. */
@@ -91,6 +92,8 @@ module_param(fqs_holdoff, int, 0444);
MODULE_PARM_DESC(fqs_holdoff, "Holdoff time within fqs bursts (us)");
module_param(fqs_stutter, int, 0444);
MODULE_PARM_DESC(fqs_stutter, "Wait time between fqs bursts (s)");
+module_param(shutdown_secs, int, 0444);
+MODULE_PARM_DESC(shutdown_secs, "Shutdown time (s), zero to disable.");
module_param(test_boost, int, 0444);
MODULE_PARM_DESC(test_boost, "Test RCU prio boost: 0=no, 1=maybe, 2=yes.");
module_param(test_boost_interval, int, 0444);
@@ -119,6 +122,7 @@ static struct task_struct *shuffler_task;
static struct task_struct *stutter_task;
static struct task_struct *fqs_task;
static struct task_struct *boost_tasks[NR_CPUS];
+static struct task_struct *shutdown_task;
#define RCU_TORTURE_PIPE_LEN 10
@@ -167,6 +171,7 @@ int rcutorture_runnable = RCUTORTURE_RUNNABLE_INIT;
#define rcu_can_boost() 0
#endif /* #else #if defined(CONFIG_RCU_BOOST) && !defined(CONFIG_HOTPLUG_CPU) */
+static unsigned long shutdown_time; /* jiffies to system shutdown. */
static unsigned long boost_starttime; /* jiffies of next boost test start. */
DEFINE_MUTEX(boost_mutex); /* protect setting boost_starttime */
/* and boost task create/destroy. */
@@ -182,6 +187,9 @@ static int fullstop = FULLSTOP_RMMOD;
*/
static DEFINE_MUTEX(fullstop_mutex);
+/* Forward reference. */
+static void rcu_torture_cleanup(void);
+
/*
* Detect and respond to a system shutdown.
*/
@@ -1250,12 +1258,12 @@ rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, char *tag)
"shuffle_interval=%d stutter=%d irqreader=%d "
"fqs_duration=%d fqs_holdoff=%d fqs_stutter=%d "
"test_boost=%d/%d test_boost_interval=%d "
- "test_boost_duration=%d\n",
+ "test_boost_duration=%d shutdown_secs=%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);
+ test_boost_interval, test_boost_duration, shutdown_secs);
}
static struct notifier_block rcutorture_shutdown_nb = {
@@ -1305,6 +1313,43 @@ static int rcutorture_booster_init(int cpu)
return 0;
}
+/*
+ * Cause the rcutorture test to shutdown the system after the test has
+ * run for the time specified by the shutdown_secs module parameter.
+ */
+static int
+rcu_torture_shutdown(void *arg)
+{
+ long delta;
+ unsigned long jiffies_snap;
+
+ VERBOSE_PRINTK_STRING("rcu_torture_shutdown task started");
+ jiffies_snap = ACCESS_ONCE(jiffies);
+ while (ULONG_CMP_LT(jiffies_snap, shutdown_time) &&
+ !kthread_should_stop()) {
+ delta = shutdown_time - jiffies_snap;
+ if (verbose)
+ printk(KERN_ALERT "%s" TORTURE_FLAG
+ "rcu_torture_shutdown task: %lu "
+ "jiffies remaining\n",
+ torture_type, delta);
+ schedule_timeout_interruptible(delta);
+ jiffies_snap = ACCESS_ONCE(jiffies);
+ }
+ if (ULONG_CMP_LT(jiffies, shutdown_time)) {
+ VERBOSE_PRINTK_STRING("rcu_torture_shutdown task stopping");
+ return 0;
+ }
+
+ /* OK, shut down the system. */
+
+ VERBOSE_PRINTK_STRING("rcu_torture_shutdown task shutting down system");
+ shutdown_task = NULL; /* Avoid self-kill deadlock. */
+ rcu_torture_cleanup(); /* Get the success/failure message. */
+ kernel_power_off(); /* Shut down the system. */
+ return 0;
+}
+
static int rcutorture_cpu_notify(struct notifier_block *self,
unsigned long action, void *hcpu)
{
@@ -1409,6 +1454,10 @@ rcu_torture_cleanup(void)
for_each_possible_cpu(i)
rcutorture_booster_cleanup(i);
}
+ if (shutdown_task != NULL) {
+ VERBOSE_PRINTK_STRING("Stopping rcu_torture_shutdown task");
+ kthread_stop(shutdown_task);
+ }
/* Wait for all RCU callbacks to fire. */
@@ -1625,6 +1674,17 @@ rcu_torture_init(void)
}
}
}
+ if (shutdown_secs > 0) {
+ shutdown_time = jiffies + shutdown_secs * HZ;
+ shutdown_task = kthread_run(rcu_torture_shutdown, NULL,
+ "rcu_torture_shutdown");
+ if (IS_ERR(shutdown_task)) {
+ firsterr = PTR_ERR(shutdown_task);
+ VERBOSE_PRINTK_ERRSTRING("Failed to create shutdown");
+ shutdown_task = NULL;
+ goto unwind;
+ }
+ }
register_reboot_notifier(&rcutorture_shutdown_nb);
rcutorture_record_test_transition();
mutex_unlock(&fullstop_mutex);
--
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