projects/linux·blob v2.6.21 · refs

441 lines · 9.0 KiB

1/*
2 * RT-Mutex-tester: scriptable tester for rt mutexes
3 *
4 * started by Thomas Gleixner:
5 *
6 * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <[email protected]>
7 *
8 */
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>
17
18#include "rtmutex.h"
19
20#define MAX_RT_TEST_THREADS 8
21#define MAX_RT_TEST_MUTEXES 8
22
23static spinlock_t rttest_lock;
24static atomic_t rttest_event;
25
26struct test_thread_data {
27 int opcode;
28 int opdata;
29 int mutexes[MAX_RT_TEST_MUTEXES];
30 int bkl;
31 int event;
32 struct sys_device sysdev;
33};
34
35static struct test_thread_data thread_data[MAX_RT_TEST_THREADS];
36static struct task_struct *threads[MAX_RT_TEST_THREADS];
37static struct rt_mutex mutexes[MAX_RT_TEST_MUTEXES];
38
39enum test_opcodes {
40 RTTEST_NOP = 0,
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 */
54};
55
56static int handle_op(struct test_thread_data *td, int lockwakeup)
57{
58 int i, id, ret = -EINVAL;
59
60 switch(td->opcode) {
61
62 case RTTEST_NOP:
63 return 0;
64
65 case RTTEST_LOCKCONT:
66 td->mutexes[td->opdata] = 1;
67 td->event = atomic_add_return(1, &rttest_event);
68 return 0;
69
70 case RTTEST_RESET:
71 for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) {
72 if (td->mutexes[i] == 4) {
73 rt_mutex_unlock(&mutexes[i]);
74 td->mutexes[i] = 0;
75 }
76 }
77
78 if (!lockwakeup && td->bkl == 4) {
79 unlock_kernel();
80 td->bkl = 0;
81 }
82 return 0;
83
84 case RTTEST_RESETEVENT:
85 atomic_set(&rttest_event, 0);
86 return 0;
87
88 default:
89 if (lockwakeup)
90 return ret;
91 }
92
93 switch(td->opcode) {
94
95 case RTTEST_LOCK:
96 case RTTEST_LOCKNOWAIT:
97 id = td->opdata;
98 if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
99 return ret;
100
101 td->mutexes[id] = 1;
102 td->event = atomic_add_return(1, &rttest_event);
103 rt_mutex_lock(&mutexes[id]);
104 td->event = atomic_add_return(1, &rttest_event);
105 td->mutexes[id] = 4;
106 return 0;
107
108 case RTTEST_LOCKINT:
109 case RTTEST_LOCKINTNOWAIT:
110 id = td->opdata;
111 if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
112 return ret;
113
114 td->mutexes[id] = 1;
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;
120
121 case RTTEST_UNLOCK:
122 id = td->opdata;
123 if (id < 0 || id >= MAX_RT_TEST_MUTEXES || td->mutexes[id] != 4)
124 return ret;
125
126 td->event = atomic_add_return(1, &rttest_event);
127 rt_mutex_unlock(&mutexes[id]);
128 td->event = atomic_add_return(1, &rttest_event);
129 td->mutexes[id] = 0;
130 return 0;
131
132 case RTTEST_LOCKBKL:
133 if (td->bkl)
134 return 0;
135 td->bkl = 1;
136 lock_kernel();
137 td->bkl = 4;
138 return 0;
139
140 case RTTEST_UNLOCKBKL:
141 if (td->bkl != 4)
142 break;
143 unlock_kernel();
144 td->bkl = 0;
145 return 0;
146
147 default:
148 break;
149 }
150 return ret;
151}
152
153/*
154 * Schedule replacement for rtsem_down(). Only called for threads with
155 * PF_MUTEX_TESTER set.
156 *
157 * This allows us to have finegrained control over the event flow.
158 *
159 */
160void schedule_rt_mutex_test(struct rt_mutex *mutex)
161{
162 int tid, op, dat;
163 struct test_thread_data *td;
164
165 /* We have to lookup the task */
166 for (tid = 0; tid < MAX_RT_TEST_THREADS; tid++) {
167 if (threads[tid] == current)
168 break;
169 }
170
171 BUG_ON(tid == MAX_RT_TEST_THREADS);
172
173 td = &thread_data[tid];
174
175 op = td->opcode;
176 dat = td->opdata;
177
178 switch (op) {
179 case RTTEST_LOCK:
180 case RTTEST_LOCKINT:
181 case RTTEST_LOCKNOWAIT:
182 case RTTEST_LOCKINTNOWAIT:
183 if (mutex != &mutexes[dat])
184 break;
185
186 if (td->mutexes[dat] != 1)
187 break;
188
189 td->mutexes[dat] = 2;
190 td->event = atomic_add_return(1, &rttest_event);
191 break;
192
193 case RTTEST_LOCKBKL:
194 default:
195 break;
196 }
197
198 schedule();
199
200
201 switch (op) {
202 case RTTEST_LOCK:
203 case RTTEST_LOCKINT:
204 if (mutex != &mutexes[dat])
205 return;
206
207 if (td->mutexes[dat] != 2)
208 return;
209
210 td->mutexes[dat] = 3;
211 td->event = atomic_add_return(1, &rttest_event);
212 break;
213
214 case RTTEST_LOCKNOWAIT:
215 case RTTEST_LOCKINTNOWAIT:
216 if (mutex != &mutexes[dat])
217 return;
218
219 if (td->mutexes[dat] != 2)
220 return;
221
222 td->mutexes[dat] = 1;
223 td->event = atomic_add_return(1, &rttest_event);
224 return;
225
226 case RTTEST_LOCKBKL:
227 return;
228 default:
229 return;
230 }
231
232 td->opcode = 0;
233
234 for (;;) {
235 set_current_state(TASK_INTERRUPTIBLE);
236
237 if (td->opcode > 0) {
238 int ret;
239
240 set_current_state(TASK_RUNNING);
241 ret = handle_op(td, 1);
242 set_current_state(TASK_INTERRUPTIBLE);
243 if (td->opcode == RTTEST_LOCKCONT)
244 break;
245 td->opcode = ret;
246 }
247
248 /* Wait for the next command to be executed */
249 schedule();
250 }
251
252 /* Restore previous command and data */
253 td->opcode = op;
254 td->opdata = dat;
255}
256
257static int test_func(void *data)
258{
259 struct test_thread_data *td = data;
260 int ret;
261
262 current->flags |= PF_MUTEX_TESTER;
263 allow_signal(SIGHUP);
264
265 for(;;) {
266
267 set_current_state(TASK_INTERRUPTIBLE);
268
269 if (td->opcode > 0) {
270 set_current_state(TASK_RUNNING);
271 ret = handle_op(td, 0);
272 set_current_state(TASK_INTERRUPTIBLE);
273 td->opcode = ret;
274 }
275
276 /* Wait for the next command to be executed */
277 schedule();
278 try_to_freeze();
279
280 if (signal_pending(current))
281 flush_signals(current);
282
283 if(kthread_should_stop())
284 break;
285 }
286 return 0;
287}
288
289/**
290 * sysfs_test_command - interface for test commands
291 * @dev: thread reference
292 * @buf: command for actual step
293 * @count: length of buffer
294 *
295 * command syntax:
296 *
297 * opcode:data
298 */
299static ssize_t sysfs_test_command(struct sys_device *dev, const char *buf,
300 size_t count)
301{
302 struct sched_param schedpar;
303 struct test_thread_data *td;
304 char cmdbuf[32];
305 int op, dat, tid, ret;
306
307 td = container_of(dev, struct test_thread_data, sysdev);
308 tid = td->sysdev.id;
309
310 /* strings from sysfs write are not 0 terminated! */
311 if (count >= sizeof(cmdbuf))
312 return -EINVAL;
313
314 /* strip of \n: */
315 if (buf[count-1] == '\n')
316 count--;
317 if (count < 1)
318 return -EINVAL;
319
320 memcpy(cmdbuf, buf, count);
321 cmdbuf[count] = 0;
322
323 if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2)
324 return -EINVAL;
325
326 switch (op) {
327 case RTTEST_SCHEDOT:
328 schedpar.sched_priority = 0;
329 ret = sched_setscheduler(threads[tid], SCHED_NORMAL, &schedpar);
330 if (ret)
331 return ret;
332 set_user_nice(current, 0);
333 break;
334
335 case RTTEST_SCHEDRT:
336 schedpar.sched_priority = dat;
337 ret = sched_setscheduler(threads[tid], SCHED_FIFO, &schedpar);
338 if (ret)
339 return ret;
340 break;
341
342 case RTTEST_SIGNAL:
343 send_sig(SIGHUP, threads[tid], 0);
344 break;
345
346 default:
347 if (td->opcode > 0)
348 return -EBUSY;
349 td->opdata = dat;
350 td->opcode = op;
351 wake_up_process(threads[tid]);
352 }
353
354 return count;
355}
356
357/**
358 * sysfs_test_status - sysfs interface for rt tester
359 * @dev: thread to query
360 * @buf: char buffer to be filled with thread status info
361 */
362static ssize_t sysfs_test_status(struct sys_device *dev, char *buf)
363{
364 struct test_thread_data *td;
365 struct task_struct *tsk;
366 char *curr = buf;
367 int i;
368
369 td = container_of(dev, struct test_thread_data, sysdev);
370 tsk = threads[td->sysdev.id];
371
372 spin_lock(&rttest_lock);
373
374 curr += sprintf(curr,
375 "O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, K: %d, M:",
376 td->opcode, td->event, tsk->state,
377 (MAX_RT_PRIO - 1) - tsk->prio,
378 (MAX_RT_PRIO - 1) - tsk->normal_prio,
379 tsk->pi_blocked_on, td->bkl);
380
381 for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--)
382 curr += sprintf(curr, "%d", td->mutexes[i]);
383
384 spin_unlock(&rttest_lock);
385
386 curr += sprintf(curr, ", T: %p, R: %p\n", tsk,
387 mutexes[td->sysdev.id].owner);
388
389 return curr - buf;
390}
391
392static SYSDEV_ATTR(status, 0600, sysfs_test_status, NULL);
393static SYSDEV_ATTR(command, 0600, NULL, sysfs_test_command);
394
395static struct sysdev_class rttest_sysclass = {
396 set_kset_name("rttest"),
397};
398
399static int init_test_thread(int id)
400{
401 thread_data[id].sysdev.cls = &rttest_sysclass;
402 thread_data[id].sysdev.id = id;
403
404 threads[id] = kthread_run(test_func, &thread_data[id], "rt-test-%d", id);
405 if (IS_ERR(threads[id]))
406 return PTR_ERR(threads[id]);
407
408 return sysdev_register(&thread_data[id].sysdev);
409}
410
411static int init_rttest(void)
412{
413 int ret, i;
414
415 spin_lock_init(&rttest_lock);
416
417 for (i = 0; i < MAX_RT_TEST_MUTEXES; i++)
418 rt_mutex_init(&mutexes[i]);
419
420 ret = sysdev_class_register(&rttest_sysclass);
421 if (ret)
422 return ret;
423
424 for (i = 0; i < MAX_RT_TEST_THREADS; i++) {
425 ret = init_test_thread(i);
426 if (ret)
427 break;
428 ret = sysdev_create_file(&thread_data[i].sysdev, &attr_status);
429 if (ret)
430 break;
431 ret = sysdev_create_file(&thread_data[i].sysdev, &attr_command);
432 if (ret)
433 break;
434 }
435
436 printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" );
437
438 return ret;
439}
440
441device_initcall(init_rttest);