rcutorture: Abstract stutter_wait()

Because stuttering the test load (stopping and restarting it) is useful
for non-RCU testing, this commit moves the load-stuttering functionality
to kernel/torture.c.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
This commit is contained in:
Paul E. McKenney 2014-01-31 11:57:43 -08:00
parent fac480efcb
commit 628edaa506
3 changed files with 104 additions and 59 deletions

View File

@ -75,8 +75,13 @@ int torture_shuffle_init(long shuffint);
/* Shutdown task absorption, for when the tasks cannot safely be killed. */
void torture_shutdown_absorb(const char *title);
/* Task stuttering, which forces load/no-load transitions. */
void stutter_wait(const char *title);
int torture_stutter_init(int s);
void torture_stutter_cleanup(void);
/* Initialization and cleanup. */
void torture_init_begin(char *ttype, bool v);
void torture_init_begin(char *ttype, bool v, int *runnable);
void torture_init_end(void);
bool torture_cleanup(void);
bool torture_must_stop(void);

View File

@ -103,7 +103,6 @@ static struct task_struct *writer_task;
static struct task_struct **fakewriter_tasks;
static struct task_struct **reader_tasks;
static struct task_struct *stats_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;
@ -145,8 +144,6 @@ static long n_barrier_attempts;
static long n_barrier_successes;
static struct list_head rcu_torture_removed;
static int stutter_pause_test;
#if defined(MODULE) || defined(CONFIG_RCU_TORTURE_TEST_RUNNABLE)
#define RCUTORTURE_RUNNABLE_INIT 1
#else
@ -222,18 +219,6 @@ rcu_torture_free(struct rcu_torture *p)
spin_unlock_bh(&rcu_torture_lock);
}
static void
rcu_stutter_wait(const char *title)
{
while (stutter_pause_test || !rcutorture_runnable) {
if (rcutorture_runnable)
schedule_timeout_interruptible(1);
else
schedule_timeout_interruptible(round_jiffies_relative(HZ));
torture_shutdown_absorb(title);
}
}
/*
* Operations vector for selecting different types of tests.
*/
@ -571,7 +556,7 @@ static int rcu_torture_boost(void *arg)
oldstarttime = boost_starttime;
while (ULONG_CMP_LT(jiffies, oldstarttime)) {
schedule_timeout_interruptible(oldstarttime - jiffies);
rcu_stutter_wait("rcu_torture_boost");
stutter_wait("rcu_torture_boost");
if (torture_must_stop())
goto checkwait;
}
@ -593,7 +578,7 @@ static int rcu_torture_boost(void *arg)
call_rcu_time = jiffies;
}
cond_resched();
rcu_stutter_wait("rcu_torture_boost");
stutter_wait("rcu_torture_boost");
if (torture_must_stop())
goto checkwait;
}
@ -618,7 +603,7 @@ static int rcu_torture_boost(void *arg)
}
/* Go do the stutter. */
checkwait: rcu_stutter_wait("rcu_torture_boost");
checkwait: stutter_wait("rcu_torture_boost");
} while (!torture_must_stop());
/* Clean up and exit. */
@ -656,7 +641,7 @@ rcu_torture_fqs(void *arg)
udelay(fqs_holdoff);
fqs_burst_remaining -= fqs_holdoff;
}
rcu_stutter_wait("rcu_torture_fqs");
stutter_wait("rcu_torture_fqs");
} while (!torture_must_stop());
VERBOSE_TOROUT_STRING("rcu_torture_fqs task stopping");
torture_shutdown_absorb("rcu_torture_fqs");
@ -728,7 +713,7 @@ rcu_torture_writer(void *arg)
}
}
rcutorture_record_progress(++rcu_torture_current_version);
rcu_stutter_wait("rcu_torture_writer");
stutter_wait("rcu_torture_writer");
} while (!torture_must_stop());
VERBOSE_TOROUT_STRING("rcu_torture_writer task stopping");
torture_shutdown_absorb("rcu_torture_writer");
@ -765,7 +750,7 @@ rcu_torture_fakewriter(void *arg)
} else {
cur_ops->exp_sync();
}
rcu_stutter_wait("rcu_torture_fakewriter");
stutter_wait("rcu_torture_fakewriter");
} while (!torture_must_stop());
VERBOSE_TOROUT_STRING("rcu_torture_fakewriter task stopping");
@ -910,7 +895,7 @@ rcu_torture_reader(void *arg)
preempt_enable();
cur_ops->readunlock(idx);
schedule();
rcu_stutter_wait("rcu_torture_reader");
stutter_wait("rcu_torture_reader");
} while (!torture_must_stop());
VERBOSE_TOROUT_STRING("rcu_torture_reader task stopping");
torture_shutdown_absorb("rcu_torture_reader");
@ -1034,25 +1019,6 @@ rcu_torture_stats(void *arg)
return 0;
}
/* Cause the rcutorture test to "stutter", starting and stopping all
* threads periodically.
*/
static int
rcu_torture_stutter(void *arg)
{
VERBOSE_TOROUT_STRING("rcu_torture_stutter task started");
do {
schedule_timeout_interruptible(stutter * HZ);
stutter_pause_test = 1;
if (!kthread_should_stop())
schedule_timeout_interruptible(stutter * HZ);
stutter_pause_test = 0;
torture_shutdown_absorb("rcu_torture_stutter");
} while (!kthread_should_stop());
VERBOSE_TOROUT_STRING("rcu_torture_stutter task stopping");
return 0;
}
static inline void
rcu_torture_print_module_parms(struct rcu_torture_ops *cur_ops, const char *tag)
{
@ -1403,11 +1369,7 @@ rcu_torture_cleanup(void)
rcu_torture_barrier_cleanup();
rcu_torture_stall_cleanup();
if (stutter_task) {
VERBOSE_TOROUT_STRING("Stopping rcu_torture_stutter task");
kthread_stop(stutter_task);
}
stutter_task = NULL;
torture_stutter_cleanup();
if (writer_task) {
VERBOSE_TOROUT_STRING("Stopping rcu_torture_writer task");
@ -1548,7 +1510,7 @@ rcu_torture_init(void)
&rcu_ops, &rcu_bh_ops, &srcu_ops, &sched_ops,
};
torture_init_begin(torture_type, verbose);
torture_init_begin(torture_type, verbose, &rcutorture_runnable);
/* Process args and tell the world that the torturer is on the job. */
for (i = 0; i < ARRAY_SIZE(torture_ops); i++) {
@ -1682,21 +1644,14 @@ rcu_torture_init(void)
if (stutter < 0)
stutter = 0;
if (stutter) {
/* Create the stutter thread */
stutter_task = kthread_run(rcu_torture_stutter, NULL,
"rcu_torture_stutter");
if (IS_ERR(stutter_task)) {
firsterr = PTR_ERR(stutter_task);
VERBOSE_TOROUT_ERRSTRING("Failed to create stutter");
stutter_task = NULL;
firsterr = torture_stutter_init(stutter * HZ);
if (firsterr)
goto unwind;
}
torture_shuffle_task_register(stutter_task);
}
if (fqs_duration < 0)
fqs_duration = 0;
if (fqs_duration) {
/* Create the stutter thread */
/* Create the fqs thread */
fqs_task = kthread_run(rcu_torture_fqs, NULL,
"rcu_torture_fqs");
if (IS_ERR(fqs_task)) {

View File

@ -58,6 +58,7 @@ static bool verbose;
#define FULLSTOP_RMMOD 2 /* Normal rmmod of torture. */
static int fullstop = FULLSTOP_RMMOD;
static DEFINE_MUTEX(fullstop_mutex);
static int *torture_runnable;
#ifdef CONFIG_HOTPLUG_CPU
@ -452,17 +453,101 @@ static struct notifier_block torture_shutdown_nb = {
.notifier_call = torture_shutdown_notify,
};
/*
* Variables for stuttering, which means to periodically pause and
* restart testing in order to catch bugs that appear when load is
* suddenly applied to or removed from the system.
*/
static struct task_struct *stutter_task;
static int stutter_pause_test;
static int stutter;
/*
* Block until the stutter interval ends. This must be called periodically
* by all running kthreads that need to be subject to stuttering.
*/
void stutter_wait(const char *title)
{
while (ACCESS_ONCE(stutter_pause_test) ||
(torture_runnable && !ACCESS_ONCE(*torture_runnable))) {
if (stutter_pause_test)
schedule_timeout_interruptible(1);
else
schedule_timeout_interruptible(round_jiffies_relative(HZ));
torture_shutdown_absorb(title);
}
}
EXPORT_SYMBOL_GPL(stutter_wait);
/*
* Cause the torture test to "stutter", starting and stopping all
* threads periodically.
*/
static int torture_stutter(void *arg)
{
VERBOSE_TOROUT_STRING("torture_stutter task started");
do {
if (!torture_must_stop()) {
schedule_timeout_interruptible(stutter);
ACCESS_ONCE(stutter_pause_test) = 1;
}
if (!torture_must_stop())
schedule_timeout_interruptible(stutter);
ACCESS_ONCE(stutter_pause_test) = 0;
torture_shutdown_absorb("torture_stutter");
} while (!torture_must_stop());
VERBOSE_TOROUT_STRING("torture_stutter task stopping");
return 0;
}
/*
* Initialize and kick off the torture_stutter kthread.
*/
int torture_stutter_init(int s)
{
int ret;
stutter = s;
stutter_task = kthread_run(torture_stutter, NULL, "torture_stutter");
if (IS_ERR(stutter_task)) {
ret = PTR_ERR(stutter_task);
VERBOSE_TOROUT_ERRSTRING("Failed to create stutter");
stutter_task = NULL;
return ret;
}
torture_shuffle_task_register(stutter_task);
return 0;
}
EXPORT_SYMBOL_GPL(torture_stutter_init);
/*
* Cleanup after the torture_stutter kthread.
*/
void torture_stutter_cleanup(void)
{
if (!stutter_task)
return;
VERBOSE_TOROUT_STRING("Stopping torture_stutter task");
kthread_stop(stutter_task);
stutter_task = NULL;
}
EXPORT_SYMBOL_GPL(torture_stutter_cleanup);
/*
* Initialize torture module. Please note that this is -not- invoked via
* the usual module_init() mechanism, but rather by an explicit call from
* the client torture module. This call must be paired with a later
* torture_init_end().
*
* The runnable parameter points to a flag that controls whether or not
* the test is currently runnable. If there is no such flag, pass in NULL.
*/
void __init torture_init_begin(char *ttype, bool v)
void __init torture_init_begin(char *ttype, bool v, int *runnable)
{
mutex_lock(&fullstop_mutex);
torture_type = ttype;
verbose = v;
torture_runnable = runnable;
fullstop = FULLSTOP_DONTSTOP;
}