2 * RT-Mutex-tester: scriptable tester for rt mutexes
4 * started by Thomas Gleixner:
6 * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
9 #include <linux/kthread.h>
10 #include <linux/module.h>
11 #include <linux/sched.h>
12 #include <linux/smp_lock.h>
13 #include <linux/spinlock.h>
14 #include <linux/sysdev.h>
15 #include <linux/timer.h>
16 #include <linux/freezer.h>
20 #define MAX_RT_TEST_THREADS 8
21 #define MAX_RT_TEST_MUTEXES 8
23 static spinlock_t rttest_lock;
24 static atomic_t rttest_event;
26 struct test_thread_data {
29 int mutexes[MAX_RT_TEST_MUTEXES];
32 struct sys_device sysdev;
35 static struct test_thread_data thread_data[MAX_RT_TEST_THREADS];
36 static struct task_struct *threads[MAX_RT_TEST_THREADS];
37 static struct rt_mutex mutexes[MAX_RT_TEST_MUTEXES];
41 RTTEST_SCHEDOT, /* 1 Sched other, data = nice */
42 RTTEST_SCHEDRT, /* 2 Sched fifo, data = prio */
43 RTTEST_LOCK, /* 3 Lock uninterruptible, data = lockindex */
44 RTTEST_LOCKNOWAIT, /* 4 Lock uninterruptible no wait in wakeup, data = lockindex */
45 RTTEST_LOCKINT, /* 5 Lock interruptible, data = lockindex */
46 RTTEST_LOCKINTNOWAIT, /* 6 Lock interruptible no wait in wakeup, data = lockindex */
47 RTTEST_LOCKCONT, /* 7 Continue locking after the wakeup delay */
48 RTTEST_UNLOCK, /* 8 Unlock, data = lockindex */
49 RTTEST_LOCKBKL, /* 9 Lock BKL */
50 RTTEST_UNLOCKBKL, /* 10 Unlock BKL */
51 RTTEST_SIGNAL, /* 11 Signal other test thread, data = thread id */
52 RTTEST_RESETEVENT = 98, /* 98 Reset event counter */
53 RTTEST_RESET = 99, /* 99 Reset all pending operations */
56 static int handle_op(struct test_thread_data *td, int lockwakeup)
58 int i, id, ret = -EINVAL;
66 td->mutexes[td->opdata] = 1;
67 td->event = atomic_add_return(1, &rttest_event);
71 for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) {
72 if (td->mutexes[i] == 4) {
73 rt_mutex_unlock(&mutexes[i]);
78 if (!lockwakeup && td->bkl == 4) {
84 case RTTEST_RESETEVENT:
85 atomic_set(&rttest_event, 0);
96 case RTTEST_LOCKNOWAIT:
98 if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
102 td->event = atomic_add_return(1, &rttest_event);
103 rt_mutex_lock(&mutexes[id]);
104 td->event = atomic_add_return(1, &rttest_event);
109 case RTTEST_LOCKINTNOWAIT:
111 if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
115 td->event = atomic_add_return(1, &rttest_event);
116 ret = rt_mutex_lock_interruptible(&mutexes[id], 0);
117 td->event = atomic_add_return(1, &rttest_event);
118 td->mutexes[id] = ret ? 0 : 4;
119 return ret ? -EINTR : 0;
123 if (id < 0 || id >= MAX_RT_TEST_MUTEXES || td->mutexes[id] != 4)
126 td->event = atomic_add_return(1, &rttest_event);
127 rt_mutex_unlock(&mutexes[id]);
128 td->event = atomic_add_return(1, &rttest_event);
140 case RTTEST_UNLOCKBKL:
154 * Schedule replacement for rtsem_down(). Only called for threads with
155 * PF_MUTEX_TESTER set.
157 * This allows us to have finegrained control over the event flow.
160 void schedule_rt_mutex_test(struct rt_mutex *mutex)
163 struct test_thread_data *td;
165 /* We have to lookup the task */
166 for (tid = 0; tid < MAX_RT_TEST_THREADS; tid++) {
167 if (threads[tid] == current)
171 BUG_ON(tid == MAX_RT_TEST_THREADS);
173 td = &thread_data[tid];
181 case RTTEST_LOCKNOWAIT:
182 case RTTEST_LOCKINTNOWAIT:
183 if (mutex != &mutexes[dat])
186 if (td->mutexes[dat] != 1)
189 td->mutexes[dat] = 2;
190 td->event = atomic_add_return(1, &rttest_event);
204 if (mutex != &mutexes[dat])
207 if (td->mutexes[dat] != 2)
210 td->mutexes[dat] = 3;
211 td->event = atomic_add_return(1, &rttest_event);
214 case RTTEST_LOCKNOWAIT:
215 case RTTEST_LOCKINTNOWAIT:
216 if (mutex != &mutexes[dat])
219 if (td->mutexes[dat] != 2)
222 td->mutexes[dat] = 1;
223 td->event = atomic_add_return(1, &rttest_event);
235 set_current_state(TASK_INTERRUPTIBLE);
237 if (td->opcode > 0) {
240 set_current_state(TASK_RUNNING);
241 ret = handle_op(td, 1);
242 set_current_state(TASK_INTERRUPTIBLE);
243 if (td->opcode == RTTEST_LOCKCONT)
248 /* Wait for the next command to be executed */
252 /* Restore previous command and data */
257 static int test_func(void *data)
259 struct test_thread_data *td = data;
262 current->flags |= PF_MUTEX_TESTER;
264 allow_signal(SIGHUP);
268 set_current_state(TASK_INTERRUPTIBLE);
270 if (td->opcode > 0) {
271 set_current_state(TASK_RUNNING);
272 ret = handle_op(td, 0);
273 set_current_state(TASK_INTERRUPTIBLE);
277 /* Wait for the next command to be executed */
281 if (signal_pending(current))
282 flush_signals(current);
284 if(kthread_should_stop())
291 * sysfs_test_command - interface for test commands
292 * @dev: thread reference
293 * @buf: command for actual step
294 * @count: length of buffer
300 static ssize_t sysfs_test_command(struct sys_device *dev, struct sysdev_attribute *attr,
301 const char *buf, size_t count)
303 struct sched_param schedpar;
304 struct test_thread_data *td;
306 int op, dat, tid, ret;
308 td = container_of(dev, struct test_thread_data, sysdev);
311 /* strings from sysfs write are not 0 terminated! */
312 if (count >= sizeof(cmdbuf))
316 if (buf[count-1] == '\n')
321 memcpy(cmdbuf, buf, count);
324 if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2)
329 schedpar.sched_priority = 0;
330 ret = sched_setscheduler(threads[tid], SCHED_NORMAL, &schedpar);
333 set_user_nice(current, 0);
337 schedpar.sched_priority = dat;
338 ret = sched_setscheduler(threads[tid], SCHED_FIFO, &schedpar);
344 send_sig(SIGHUP, threads[tid], 0);
352 wake_up_process(threads[tid]);
359 * sysfs_test_status - sysfs interface for rt tester
360 * @dev: thread to query
361 * @buf: char buffer to be filled with thread status info
363 static ssize_t sysfs_test_status(struct sys_device *dev, struct sysdev_attribute *attr,
366 struct test_thread_data *td;
367 struct task_struct *tsk;
371 td = container_of(dev, struct test_thread_data, sysdev);
372 tsk = threads[td->sysdev.id];
374 spin_lock(&rttest_lock);
376 curr += sprintf(curr,
377 "O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, K: %d, M:",
378 td->opcode, td->event, tsk->state,
379 (MAX_RT_PRIO - 1) - tsk->prio,
380 (MAX_RT_PRIO - 1) - tsk->normal_prio,
381 tsk->pi_blocked_on, td->bkl);
383 for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--)
384 curr += sprintf(curr, "%d", td->mutexes[i]);
386 spin_unlock(&rttest_lock);
388 curr += sprintf(curr, ", T: %p, R: %p\n", tsk,
389 mutexes[td->sysdev.id].owner);
394 static SYSDEV_ATTR(status, 0600, sysfs_test_status, NULL);
395 static SYSDEV_ATTR(command, 0600, NULL, sysfs_test_command);
397 static struct sysdev_class rttest_sysclass = {
401 static int init_test_thread(int id)
403 thread_data[id].sysdev.cls = &rttest_sysclass;
404 thread_data[id].sysdev.id = id;
406 threads[id] = kthread_run(test_func, &thread_data[id], "rt-test-%d", id);
407 if (IS_ERR(threads[id]))
408 return PTR_ERR(threads[id]);
410 return sysdev_register(&thread_data[id].sysdev);
413 static int init_rttest(void)
417 spin_lock_init(&rttest_lock);
419 for (i = 0; i < MAX_RT_TEST_MUTEXES; i++)
420 rt_mutex_init(&mutexes[i]);
422 ret = sysdev_class_register(&rttest_sysclass);
426 for (i = 0; i < MAX_RT_TEST_THREADS; i++) {
427 ret = init_test_thread(i);
430 ret = sysdev_create_file(&thread_data[i].sysdev, &attr_status);
433 ret = sysdev_create_file(&thread_data[i].sysdev, &attr_command);
438 printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" );
443 device_initcall(init_rttest);