[PATCH tip/core/rcu 37/55] rcutorture: Abstract torture_create_kthread()

From: Paul E. McKenney
Date: Mon Feb 17 2014 - 17:18:04 EST


From: "Paul E. McKenney" <paulmck@xxxxxxxxxxxxxxxxxx>

Creation of kthreads is not RCU-specific, so this commit abstracts
out torture_create_kthread(), saving a few tens of lines of code in
the process.

Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxxxxxxxxxx>
---
include/linux/torture.h | 8 +++-
kernel/rcu/rcutorture.c | 98 ++++++++++---------------------------------------
kernel/torture.c | 80 +++++++++++++++++-----------------------
3 files changed, 60 insertions(+), 126 deletions(-)

diff --git a/include/linux/torture.h b/include/linux/torture.h
index db9bc7756a32..e5264c6ecfeb 100644
--- a/include/linux/torture.h
+++ b/include/linux/torture.h
@@ -47,7 +47,7 @@
#define VERBOSE_TOROUT_STRING(s) \
do { if (verbose) pr_alert("%s" TORTURE_FLAG " %s\n", torture_type, s); } while (0)
#define VERBOSE_TOROUT_ERRSTRING(s) \
- do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! " s "\n", torture_type); } while (0)
+ do { if (verbose) pr_alert("%s" TORTURE_FLAG "!!! %s\n", torture_type, s); } while (0)

/* Definitions for a non-string torture-test module parameter. */
#define torture_parm(type, name, init, msg) \
@@ -89,5 +89,11 @@ bool torture_cleanup(void);
bool torture_must_stop(void);
bool torture_must_stop_irq(void);
void torture_kthread_stopping(char *title);
+int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
+ char *f, struct task_struct **tp);
+
+#define torture_create_kthread(n, arg, tp) \
+ _torture_create_kthread(n, (arg), #n, "Creating " #n " task", \
+ "Failed to create " #n, &(tp))

#endif /* __LINUX_TORTURE_H */
diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c
index cf365160b44f..951a5559d9fa 100644
--- a/kernel/rcu/rcutorture.c
+++ b/kernel/rcu/rcutorture.c
@@ -1104,19 +1104,9 @@ static int rcu_torture_stall(void *args)
/* Spawn CPU-stall kthread, if stall_cpu specified. */
static int __init rcu_torture_stall_init(void)
{
- int ret;
-
if (stall_cpu <= 0)
return 0;
- VERBOSE_TOROUT_STRING("Creating rcu_torture_stall task");
- stall_task = kthread_run(rcu_torture_stall, NULL, "rcu_torture_stall");
- if (IS_ERR(stall_task)) {
- ret = PTR_ERR(stall_task);
- stall_task = NULL;
- return ret;
- }
- torture_shuffle_task_register(stall_task);
- return 0;
+ return torture_create_kthread(rcu_torture_stall, NULL, stall_task);
}

/* Clean up after the CPU-stall kthread, if one was spawned. */
@@ -1225,29 +1215,13 @@ static int rcu_torture_barrier_init(void)
return -ENOMEM;
for (i = 0; i < n_barrier_cbs; i++) {
init_waitqueue_head(&barrier_cbs_wq[i]);
- VERBOSE_TOROUT_STRING("Creating rcu_torture_barrier_cbs task");
- barrier_cbs_tasks[i] = kthread_run(rcu_torture_barrier_cbs,
- (void *)(long)i,
- "rcu_torture_barrier_cbs");
- if (IS_ERR(barrier_cbs_tasks[i])) {
- ret = PTR_ERR(barrier_cbs_tasks[i]);
- VERBOSE_TOROUT_ERRSTRING("Failed to create rcu_torture_barrier_cbs");
- barrier_cbs_tasks[i] = NULL;
+ ret = torture_create_kthread(rcu_torture_barrier_cbs,
+ (void *)(long)i,
+ barrier_cbs_tasks[i]);
+ if (ret)
return ret;
- }
- torture_shuffle_task_register(barrier_cbs_tasks[i]);
}
- VERBOSE_TOROUT_STRING("Creating rcu_torture_barrier task");
- barrier_task = kthread_run(rcu_torture_barrier, NULL,
- "rcu_torture_barrier");
- if (IS_ERR(barrier_task)) {
- ret = PTR_ERR(barrier_task);
- VERBOSE_TOROUT_ERRSTRING("Failed to create rcu_torture_barrier");
- barrier_task = NULL;
- return ret;
- }
- torture_shuffle_task_register(barrier_task);
- return 0;
+ return torture_create_kthread(rcu_torture_barrier, NULL, barrier_task);
}

/* Clean up after RCU barrier testing. */
@@ -1515,17 +1489,10 @@ rcu_torture_init(void)

/* Start up the kthreads. */

- VERBOSE_TOROUT_STRING("Creating rcu_torture_writer task");
- writer_task = kthread_create(rcu_torture_writer, NULL,
- "rcu_torture_writer");
- if (IS_ERR(writer_task)) {
- firsterr = PTR_ERR(writer_task);
- VERBOSE_TOROUT_ERRSTRING("Failed to create writer");
- writer_task = NULL;
+ firsterr = torture_create_kthread(rcu_torture_writer, NULL,
+ writer_task);
+ if (firsterr)
goto unwind;
- }
- torture_shuffle_task_register(writer_task);
- wake_up_process(writer_task);
fakewriter_tasks = kzalloc(nfakewriters * sizeof(fakewriter_tasks[0]),
GFP_KERNEL);
if (fakewriter_tasks == NULL) {
@@ -1534,16 +1501,10 @@ rcu_torture_init(void)
goto unwind;
}
for (i = 0; i < nfakewriters; i++) {
- VERBOSE_TOROUT_STRING("Creating rcu_torture_fakewriter task");
- fakewriter_tasks[i] = kthread_run(rcu_torture_fakewriter, NULL,
- "rcu_torture_fakewriter");
- if (IS_ERR(fakewriter_tasks[i])) {
- firsterr = PTR_ERR(fakewriter_tasks[i]);
- VERBOSE_TOROUT_ERRSTRING("Failed to create fakewriter");
- fakewriter_tasks[i] = NULL;
+ firsterr = torture_create_kthread(rcu_torture_fakewriter,
+ NULL, fakewriter_tasks[i]);
+ if (firsterr)
goto unwind;
- }
- torture_shuffle_task_register(fakewriter_tasks[i]);
}
reader_tasks = kzalloc(nrealreaders * sizeof(reader_tasks[0]),
GFP_KERNEL);
@@ -1553,28 +1514,16 @@ rcu_torture_init(void)
goto unwind;
}
for (i = 0; i < nrealreaders; i++) {
- VERBOSE_TOROUT_STRING("Creating rcu_torture_reader task");
- reader_tasks[i] = kthread_run(rcu_torture_reader, NULL,
- "rcu_torture_reader");
- if (IS_ERR(reader_tasks[i])) {
- firsterr = PTR_ERR(reader_tasks[i]);
- VERBOSE_TOROUT_ERRSTRING("Failed to create reader");
- reader_tasks[i] = NULL;
+ firsterr = torture_create_kthread(rcu_torture_reader, NULL,
+ reader_tasks[i]);
+ if (firsterr)
goto unwind;
- }
- torture_shuffle_task_register(reader_tasks[i]);
}
if (stat_interval > 0) {
- VERBOSE_TOROUT_STRING("Creating rcu_torture_stats task");
- stats_task = kthread_run(rcu_torture_stats, NULL,
- "rcu_torture_stats");
- if (IS_ERR(stats_task)) {
- firsterr = PTR_ERR(stats_task);
- VERBOSE_TOROUT_ERRSTRING("Failed to create stats");
- stats_task = NULL;
+ firsterr = torture_create_kthread(rcu_torture_stats, NULL,
+ stats_task);
+ if (firsterr)
goto unwind;
- }
- torture_shuffle_task_register(stats_task);
}
if (test_no_idle_hz) {
firsterr = torture_shuffle_init(shuffle_interval * HZ);
@@ -1592,16 +1541,9 @@ rcu_torture_init(void)
fqs_duration = 0;
if (fqs_duration) {
/* Create the fqs thread */
- VERBOSE_TOROUT_STRING("Creating rcu_torture_fqs task");
- fqs_task = kthread_run(rcu_torture_fqs, NULL,
- "rcu_torture_fqs");
- if (IS_ERR(fqs_task)) {
- firsterr = PTR_ERR(fqs_task);
- VERBOSE_TOROUT_ERRSTRING("Failed to create fqs");
- fqs_task = NULL;
+ torture_create_kthread(rcu_torture_fqs, NULL, fqs_task);
+ if (firsterr)
goto unwind;
- }
- torture_shuffle_task_register(fqs_task);
}
if (test_boost_interval < 1)
test_boost_interval = 1;
diff --git a/kernel/torture.c b/kernel/torture.c
index 6f1c6600d183..94760f0f2923 100644
--- a/kernel/torture.c
+++ b/kernel/torture.c
@@ -180,23 +180,16 @@ torture_onoff(void *arg)
*/
int torture_onoff_init(long ooholdoff, long oointerval)
{
-#ifdef CONFIG_HOTPLUG_CPU
- int ret;
+ int ret = 0;

+#ifdef CONFIG_HOTPLUG_CPU
onoff_holdoff = ooholdoff;
onoff_interval = oointerval;
if (onoff_interval <= 0)
return 0;
- VERBOSE_TOROUT_STRING("Creating torture_onoff task");
- onoff_task = kthread_run(torture_onoff, NULL, "torture_onoff");
- if (IS_ERR(onoff_task)) {
- ret = PTR_ERR(onoff_task);
- onoff_task = NULL;
- return ret;
- }
- torture_shuffle_task_register(onoff_task);
+ ret = torture_create_kthread(torture_onoff, NULL, onoff_task);
#endif /* #ifdef CONFIG_HOTPLUG_CPU */
- return 0;
+ return ret;
}
EXPORT_SYMBOL_GPL(torture_onoff_init);

@@ -379,8 +372,6 @@ static int torture_shuffle(void *arg)
*/
int torture_shuffle_init(long shuffint)
{
- int ret;
-
shuffle_interval = shuffint;

shuffle_idle_cpu = -1;
@@ -391,17 +382,7 @@ int torture_shuffle_init(long shuffint)
}

/* Create the shuffler thread */
- VERBOSE_TOROUT_STRING("Creating torture_shuffle task");
- shuffler_task = kthread_run(torture_shuffle, NULL, "torture_shuffle");
- if (IS_ERR(shuffler_task)) {
- ret = PTR_ERR(shuffler_task);
- free_cpumask_var(shuffle_tmp_mask);
- VERBOSE_TOROUT_ERRSTRING("Failed to create shuffler");
- shuffler_task = NULL;
- return ret;
- }
- torture_shuffle_task_register(shuffler_task);
- return 0;
+ return torture_create_kthread(torture_shuffle, NULL, shuffler_task);
}
EXPORT_SYMBOL_GPL(torture_shuffle_init);

@@ -483,25 +464,16 @@ static int torture_shutdown(void *arg)
*/
int torture_shutdown_init(int ssecs, void (*cleanup)(void))
{
- int ret;
+ int ret = 0;

shutdown_secs = ssecs;
torture_shutdown_hook = cleanup;
if (shutdown_secs > 0) {
- VERBOSE_TOROUT_STRING("Creating torture_shutdown task");
shutdown_time = jiffies + shutdown_secs * HZ;
- shutdown_task = kthread_create(torture_shutdown, NULL,
- "torture_shutdown");
- if (IS_ERR(shutdown_task)) {
- ret = PTR_ERR(shutdown_task);
- VERBOSE_TOROUT_ERRSTRING("Failed to create shutdown");
- shutdown_task = NULL;
- return ret;
- }
- torture_shuffle_task_register(shutdown_task);
- wake_up_process(shutdown_task);
+ ret = torture_create_kthread(torture_shutdown, NULL,
+ shutdown_task);
}
- return 0;
+ return ret;
}
EXPORT_SYMBOL_GPL(torture_shutdown_init);

@@ -595,16 +567,8 @@ int torture_stutter_init(int s)
int ret;

stutter = s;
- VERBOSE_TOROUT_STRING("Creating torture_stutter task");
- 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;
+ ret = torture_create_kthread(torture_stutter, NULL, stutter_task);
+ return ret;
}
EXPORT_SYMBOL_GPL(torture_stutter_init);

@@ -714,3 +678,25 @@ void torture_kthread_stopping(char *title)
}
}
EXPORT_SYMBOL_GPL(torture_kthread_stopping);
+
+/*
+ * Create a generic torture kthread that is immediately runnable. If you
+ * need the kthread to be stopped so that you can do something to it before
+ * it starts, you will need to open-code your own.
+ */
+int _torture_create_kthread(int (*fn)(void *arg), void *arg, char *s, char *m,
+ char *f, struct task_struct **tp)
+{
+ int ret = 0;
+
+ VERBOSE_TOROUT_STRING(m);
+ *tp = kthread_run(fn, arg, s);
+ if (IS_ERR(*tp)) {
+ ret = PTR_ERR(*tp);
+ VERBOSE_TOROUT_ERRSTRING(f);
+ *tp = NULL;
+ }
+ torture_shuffle_task_register(*tp);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(_torture_create_kthread);
--
1.8.1.5

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