fw_cfg: Refactor extra pci roots addition
[qemu/ar7.git] / tests / rcutorture.c
blobde6f649058ef2648fef1287816145f883efc39aa
1 /*
2 * rcutorture.c: simple user-level performance/stress test of RCU.
4 * Usage:
5 * ./rcu <nreaders> rperf [ <seconds> ]
6 * Run a read-side performance test with the specified
7 * number of readers for <seconds> seconds.
8 * ./rcu <nupdaters> uperf [ <seconds> ]
9 * Run an update-side performance test with the specified
10 * number of updaters and specified duration.
11 * ./rcu <nreaders> perf [ <seconds> ]
12 * Run a combined read/update performance test with the specified
13 * number of readers and one updater and specified duration.
15 * The above tests produce output as follows:
17 * n_reads: 46008000 n_updates: 146026 nreaders: 2 nupdaters: 1 duration: 1
18 * ns/read: 43.4707 ns/update: 6848.1
20 * The first line lists the total number of RCU reads and updates executed
21 * during the test, the number of reader threads, the number of updater
22 * threads, and the duration of the test in seconds. The second line
23 * lists the average duration of each type of operation in nanoseconds,
24 * or "nan" if the corresponding type of operation was not performed.
26 * ./rcu <nreaders> stress [ <seconds> ]
27 * Run a stress test with the specified number of readers and
28 * one updater.
30 * This test produces output as follows:
32 * n_reads: 114633217 n_updates: 3903415 n_mberror: 0
33 * rcu_stress_count: 114618391 14826 0 0 0 0 0 0 0 0 0
35 * The first line lists the number of RCU read and update operations
36 * executed, followed by the number of memory-ordering violations
37 * (which will be zero in a correct RCU implementation). The second
38 * line lists the number of readers observing progressively more stale
39 * data. A correct RCU implementation will have all but the first two
40 * numbers non-zero.
42 * This program is free software; you can redistribute it and/or modify
43 * it under the terms of the GNU General Public License as published by
44 * the Free Software Foundation; either version 2 of the License, or
45 * (at your option) any later version.
47 * This program is distributed in the hope that it will be useful,
48 * but WITHOUT ANY WARRANTY; without even the implied warranty of
49 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
50 * GNU General Public License for more details.
52 * You should have received a copy of the GNU General Public License
53 * along with this program; if not, write to the Free Software
54 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
56 * Copyright (c) 2008 Paul E. McKenney, IBM Corporation.
60 * Test variables.
63 #include "qemu/osdep.h"
64 #include "qemu/atomic.h"
65 #include "qemu/rcu.h"
66 #include "qemu/thread.h"
68 int nthreadsrunning;
70 #define GOFLAG_INIT 0
71 #define GOFLAG_RUN 1
72 #define GOFLAG_STOP 2
74 static volatile int goflag = GOFLAG_INIT;
76 #define RCU_READ_RUN 1000
78 #define NR_THREADS 100
79 static QemuThread threads[NR_THREADS];
80 static struct rcu_reader_data *data[NR_THREADS];
81 static int n_threads;
84 * Statistical counts
86 * These are the sum of local counters at the end of a run.
87 * Updates are protected by a mutex.
89 static QemuMutex counts_mutex;
90 long long n_reads = 0LL;
91 long n_updates = 0L;
93 static void create_thread(void *(*func)(void *))
95 if (n_threads >= NR_THREADS) {
96 fprintf(stderr, "Thread limit of %d exceeded!\n", NR_THREADS);
97 exit(-1);
99 qemu_thread_create(&threads[n_threads], "test", func, &data[n_threads],
100 QEMU_THREAD_JOINABLE);
101 n_threads++;
104 static void wait_all_threads(void)
106 int i;
108 for (i = 0; i < n_threads; i++) {
109 qemu_thread_join(&threads[i]);
111 n_threads = 0;
115 * Performance test.
118 static void *rcu_read_perf_test(void *arg)
120 int i;
121 long long n_reads_local = 0;
123 rcu_register_thread();
125 *(struct rcu_reader_data **)arg = &rcu_reader;
126 qatomic_inc(&nthreadsrunning);
127 while (goflag == GOFLAG_INIT) {
128 g_usleep(1000);
130 while (goflag == GOFLAG_RUN) {
131 for (i = 0; i < RCU_READ_RUN; i++) {
132 rcu_read_lock();
133 rcu_read_unlock();
135 n_reads_local += RCU_READ_RUN;
137 qemu_mutex_lock(&counts_mutex);
138 n_reads += n_reads_local;
139 qemu_mutex_unlock(&counts_mutex);
141 rcu_unregister_thread();
142 return NULL;
145 static void *rcu_update_perf_test(void *arg)
147 long long n_updates_local = 0;
149 rcu_register_thread();
151 *(struct rcu_reader_data **)arg = &rcu_reader;
152 qatomic_inc(&nthreadsrunning);
153 while (goflag == GOFLAG_INIT) {
154 g_usleep(1000);
156 while (goflag == GOFLAG_RUN) {
157 synchronize_rcu();
158 n_updates_local++;
160 qemu_mutex_lock(&counts_mutex);
161 n_updates += n_updates_local;
162 qemu_mutex_unlock(&counts_mutex);
164 rcu_unregister_thread();
165 return NULL;
168 static void perftestinit(void)
170 nthreadsrunning = 0;
173 static void perftestrun(int nthreads, int duration, int nreaders, int nupdaters)
175 while (qatomic_read(&nthreadsrunning) < nthreads) {
176 g_usleep(1000);
178 goflag = GOFLAG_RUN;
179 g_usleep(duration * G_USEC_PER_SEC);
180 goflag = GOFLAG_STOP;
181 wait_all_threads();
182 printf("n_reads: %lld n_updates: %ld nreaders: %d nupdaters: %d duration: %d\n",
183 n_reads, n_updates, nreaders, nupdaters, duration);
184 printf("ns/read: %g ns/update: %g\n",
185 ((duration * 1000*1000*1000.*(double)nreaders) /
186 (double)n_reads),
187 ((duration * 1000*1000*1000.*(double)nupdaters) /
188 (double)n_updates));
189 exit(0);
192 static void perftest(int nreaders, int duration)
194 int i;
196 perftestinit();
197 for (i = 0; i < nreaders; i++) {
198 create_thread(rcu_read_perf_test);
200 create_thread(rcu_update_perf_test);
201 perftestrun(i + 1, duration, nreaders, 1);
204 static void rperftest(int nreaders, int duration)
206 int i;
208 perftestinit();
209 for (i = 0; i < nreaders; i++) {
210 create_thread(rcu_read_perf_test);
212 perftestrun(i, duration, nreaders, 0);
215 static void uperftest(int nupdaters, int duration)
217 int i;
219 perftestinit();
220 for (i = 0; i < nupdaters; i++) {
221 create_thread(rcu_update_perf_test);
223 perftestrun(i, duration, 0, nupdaters);
227 * Stress test.
230 #define RCU_STRESS_PIPE_LEN 10
232 struct rcu_stress {
233 int age; /* how many update cycles while not rcu_stress_current */
234 int mbtest;
237 struct rcu_stress rcu_stress_array[RCU_STRESS_PIPE_LEN] = { { 0 } };
238 struct rcu_stress *rcu_stress_current;
239 int n_mberror;
241 /* Updates protected by counts_mutex */
242 long long rcu_stress_count[RCU_STRESS_PIPE_LEN + 1];
245 static void *rcu_read_stress_test(void *arg)
247 int i;
248 struct rcu_stress *p;
249 int pc;
250 long long n_reads_local = 0;
251 long long rcu_stress_local[RCU_STRESS_PIPE_LEN + 1] = { 0 };
252 volatile int garbage = 0;
254 rcu_register_thread();
256 *(struct rcu_reader_data **)arg = &rcu_reader;
257 while (goflag == GOFLAG_INIT) {
258 g_usleep(1000);
260 while (goflag == GOFLAG_RUN) {
261 rcu_read_lock();
262 p = qatomic_rcu_read(&rcu_stress_current);
263 if (qatomic_read(&p->mbtest) == 0) {
264 n_mberror++;
266 rcu_read_lock();
267 for (i = 0; i < 100; i++) {
268 garbage++;
270 rcu_read_unlock();
271 pc = qatomic_read(&p->age);
272 rcu_read_unlock();
273 if ((pc > RCU_STRESS_PIPE_LEN) || (pc < 0)) {
274 pc = RCU_STRESS_PIPE_LEN;
276 rcu_stress_local[pc]++;
277 n_reads_local++;
279 qemu_mutex_lock(&counts_mutex);
280 n_reads += n_reads_local;
281 for (i = 0; i <= RCU_STRESS_PIPE_LEN; i++) {
282 rcu_stress_count[i] += rcu_stress_local[i];
284 qemu_mutex_unlock(&counts_mutex);
286 rcu_unregister_thread();
287 return NULL;
291 * Stress Test Updater
293 * The updater cycles around updating rcu_stress_current to point at
294 * one of the rcu_stress_array_entries and resets it's age. It
295 * then increments the age of all the other entries. The age
296 * will be read under an rcu_read_lock() and distribution of values
297 * calculated. The final result gives an indication of how many
298 * previously current rcu_stress entries are in flight until the RCU
299 * cycle complete.
301 static void *rcu_update_stress_test(void *arg)
303 int i, rcu_stress_idx = 0;
304 struct rcu_stress *cp = qatomic_read(&rcu_stress_current);
306 rcu_register_thread();
307 *(struct rcu_reader_data **)arg = &rcu_reader;
309 while (goflag == GOFLAG_INIT) {
310 g_usleep(1000);
313 while (goflag == GOFLAG_RUN) {
314 struct rcu_stress *p;
315 rcu_stress_idx++;
316 if (rcu_stress_idx >= RCU_STRESS_PIPE_LEN) {
317 rcu_stress_idx = 0;
319 p = &rcu_stress_array[rcu_stress_idx];
320 /* catching up with ourselves would be a bug */
321 assert(p != cp);
322 qatomic_set(&p->mbtest, 0);
323 smp_mb();
324 qatomic_set(&p->age, 0);
325 qatomic_set(&p->mbtest, 1);
326 qatomic_rcu_set(&rcu_stress_current, p);
327 cp = p;
329 * New RCU structure is now live, update pipe counts on old
330 * ones.
332 for (i = 0; i < RCU_STRESS_PIPE_LEN; i++) {
333 if (i != rcu_stress_idx) {
334 qatomic_set(&rcu_stress_array[i].age,
335 rcu_stress_array[i].age + 1);
338 synchronize_rcu();
339 n_updates++;
342 rcu_unregister_thread();
343 return NULL;
346 static void *rcu_fake_update_stress_test(void *arg)
348 rcu_register_thread();
350 *(struct rcu_reader_data **)arg = &rcu_reader;
351 while (goflag == GOFLAG_INIT) {
352 g_usleep(1000);
354 while (goflag == GOFLAG_RUN) {
355 synchronize_rcu();
356 g_usleep(1000);
359 rcu_unregister_thread();
360 return NULL;
363 static void stresstest(int nreaders, int duration)
365 int i;
367 rcu_stress_current = &rcu_stress_array[0];
368 rcu_stress_current->age = 0;
369 rcu_stress_current->mbtest = 1;
370 for (i = 0; i < nreaders; i++) {
371 create_thread(rcu_read_stress_test);
373 create_thread(rcu_update_stress_test);
374 for (i = 0; i < 5; i++) {
375 create_thread(rcu_fake_update_stress_test);
377 goflag = GOFLAG_RUN;
378 g_usleep(duration * G_USEC_PER_SEC);
379 goflag = GOFLAG_STOP;
380 wait_all_threads();
381 printf("n_reads: %lld n_updates: %ld n_mberror: %d\n",
382 n_reads, n_updates, n_mberror);
383 printf("rcu_stress_count:");
384 for (i = 0; i <= RCU_STRESS_PIPE_LEN; i++) {
385 printf(" %lld", rcu_stress_count[i]);
387 printf("\n");
388 exit(0);
391 /* GTest interface */
393 static void gtest_stress(int nreaders, int duration)
395 int i;
397 rcu_stress_current = &rcu_stress_array[0];
398 rcu_stress_current->age = 0;
399 rcu_stress_current->mbtest = 1;
400 for (i = 0; i < nreaders; i++) {
401 create_thread(rcu_read_stress_test);
403 create_thread(rcu_update_stress_test);
404 for (i = 0; i < 5; i++) {
405 create_thread(rcu_fake_update_stress_test);
407 goflag = GOFLAG_RUN;
408 g_usleep(duration * G_USEC_PER_SEC);
409 goflag = GOFLAG_STOP;
410 wait_all_threads();
411 g_assert_cmpint(n_mberror, ==, 0);
412 for (i = 2; i <= RCU_STRESS_PIPE_LEN; i++) {
413 g_assert_cmpint(rcu_stress_count[i], ==, 0);
417 static void gtest_stress_1_1(void)
419 gtest_stress(1, 1);
422 static void gtest_stress_10_1(void)
424 gtest_stress(10, 1);
427 static void gtest_stress_1_5(void)
429 gtest_stress(1, 5);
432 static void gtest_stress_10_5(void)
434 gtest_stress(10, 5);
438 * Mainprogram.
441 static void usage(int argc, char *argv[])
443 fprintf(stderr, "Usage: %s [nreaders [ [r|u]perf | stress [duration]]\n",
444 argv[0]);
445 exit(-1);
448 int main(int argc, char *argv[])
450 int nreaders = 1;
451 int duration = 1;
453 qemu_mutex_init(&counts_mutex);
454 if (argc >= 2 && argv[1][0] == '-') {
455 g_test_init(&argc, &argv, NULL);
456 if (g_test_quick()) {
457 g_test_add_func("/rcu/torture/1reader", gtest_stress_1_1);
458 g_test_add_func("/rcu/torture/10readers", gtest_stress_10_1);
459 } else {
460 g_test_add_func("/rcu/torture/1reader", gtest_stress_1_5);
461 g_test_add_func("/rcu/torture/10readers", gtest_stress_10_5);
463 return g_test_run();
466 if (argc >= 2) {
467 nreaders = strtoul(argv[1], NULL, 0);
469 if (argc > 3) {
470 duration = strtoul(argv[3], NULL, 0);
472 if (argc < 3 || strcmp(argv[2], "stress") == 0) {
473 stresstest(nreaders, duration);
474 } else if (strcmp(argv[2], "rperf") == 0) {
475 rperftest(nreaders, duration);
476 } else if (strcmp(argv[2], "uperf") == 0) {
477 uperftest(nreaders, duration);
478 } else if (strcmp(argv[2], "perf") == 0) {
479 perftest(nreaders, duration);
481 usage(argc, argv);
482 return 0;