genfio: Splitting gen_template in 2 parts
[fio.git] / gettime.c
1 /*
2  * Clock functions
3  */
4
5 #include <unistd.h>
6 #include <math.h>
7 #include <sys/time.h>
8 #include <time.h>
9
10 #include "fio.h"
11 #include "smalloc.h"
12
13 #include "hash.h"
14 #include "os/os.h"
15
16 #ifdef ARCH_HAVE_CPU_CLOCK
17 static unsigned long cycles_per_usec;
18 static unsigned long inv_cycles_per_usec;
19 #endif
20 int tsc_reliable = 0;
21
22 struct tv_valid {
23         struct timeval last_tv;
24         uint64_t last_cycles;
25         int last_tv_valid;
26 };
27 #ifdef CONFIG_TLS_THREAD
28 static __thread struct tv_valid static_tv_valid;
29 #else
30 static pthread_key_t tv_tls_key;
31 #endif
32
33 enum fio_cs fio_clock_source = FIO_PREFERRED_CLOCK_SOURCE;
34 int fio_clock_source_set = 0;
35 enum fio_cs fio_clock_source_inited = CS_INVAL;
36
37 #ifdef FIO_DEBUG_TIME
38
39 #define HASH_BITS       8
40 #define HASH_SIZE       (1 << HASH_BITS)
41
42 static struct flist_head hash[HASH_SIZE];
43 static int gtod_inited;
44
45 struct gtod_log {
46         struct flist_head list;
47         void *caller;
48         unsigned long calls;
49 };
50
51 static struct gtod_log *find_hash(void *caller)
52 {
53         unsigned long h = hash_ptr(caller, HASH_BITS);
54         struct flist_head *entry;
55
56         flist_for_each(entry, &hash[h]) {
57                 struct gtod_log *log = flist_entry(entry, struct gtod_log,
58                                                                         list);
59
60                 if (log->caller == caller)
61                         return log;
62         }
63
64         return NULL;
65 }
66
67 static struct gtod_log *find_log(void *caller)
68 {
69         struct gtod_log *log = find_hash(caller);
70
71         if (!log) {
72                 unsigned long h;
73
74                 log = malloc(sizeof(*log));
75                 INIT_FLIST_HEAD(&log->list);
76                 log->caller = caller;
77                 log->calls = 0;
78
79                 h = hash_ptr(caller, HASH_BITS);
80                 flist_add_tail(&log->list, &hash[h]);
81         }
82
83         return log;
84 }
85
86 static void gtod_log_caller(void *caller)
87 {
88         if (gtod_inited) {
89                 struct gtod_log *log = find_log(caller);
90
91                 log->calls++;
92         }
93 }
94
95 static void fio_exit fio_dump_gtod(void)
96 {
97         unsigned long total_calls = 0;
98         int i;
99
100         for (i = 0; i < HASH_SIZE; i++) {
101                 struct flist_head *entry;
102                 struct gtod_log *log;
103
104                 flist_for_each(entry, &hash[i]) {
105                         log = flist_entry(entry, struct gtod_log, list);
106
107                         printf("function %p, calls %lu\n", log->caller,
108                                                                 log->calls);
109                         total_calls += log->calls;
110                 }
111         }
112
113         printf("Total %lu gettimeofday\n", total_calls);
114 }
115
116 static void fio_init gtod_init(void)
117 {
118         int i;
119
120         for (i = 0; i < HASH_SIZE; i++)
121                 INIT_FLIST_HEAD(&hash[i]);
122
123         gtod_inited = 1;
124 }
125
126 #endif /* FIO_DEBUG_TIME */
127
128 #ifdef CONFIG_CLOCK_GETTIME
129 static int fill_clock_gettime(struct timespec *ts)
130 {
131 #ifdef CONFIG_CLOCK_MONOTONIC
132         return clock_gettime(CLOCK_MONOTONIC, ts);
133 #else
134         return clock_gettime(CLOCK_REALTIME, ts);
135 #endif
136 }
137 #endif
138
139 static void *__fio_gettime(struct timeval *tp)
140 {
141         struct tv_valid *tv;
142
143 #ifdef CONFIG_TLS_THREAD
144         tv = &static_tv_valid;
145 #else
146         tv = pthread_getspecific(tv_tls_key);
147 #endif
148
149         switch (fio_clock_source) {
150 #ifdef CONFIG_GETTIMEOFDAY
151         case CS_GTOD:
152                 gettimeofday(tp, NULL);
153                 break;
154 #endif
155 #ifdef CONFIG_CLOCK_GETTIME
156         case CS_CGETTIME: {
157                 struct timespec ts;
158
159                 if (fill_clock_gettime(&ts) < 0) {
160                         log_err("fio: clock_gettime fails\n");
161                         assert(0);
162                 }
163
164                 tp->tv_sec = ts.tv_sec;
165                 tp->tv_usec = ts.tv_nsec / 1000;
166                 break;
167                 }
168 #endif
169 #ifdef ARCH_HAVE_CPU_CLOCK
170         case CS_CPUCLOCK: {
171                 uint64_t usecs, t;
172
173                 t = get_cpu_clock();
174                 if (tv && t < tv->last_cycles) {
175                         dprint(FD_TIME, "CPU clock going back in time\n");
176                         t = tv->last_cycles;
177                 } else if (tv)
178                         tv->last_cycles = t;
179
180                 usecs = (t * inv_cycles_per_usec) / 16777216UL;
181                 tp->tv_sec = usecs / 1000000;
182                 tp->tv_usec = usecs % 1000000;
183                 break;
184                 }
185 #endif
186         default:
187                 log_err("fio: invalid clock source %d\n", fio_clock_source);
188                 break;
189         }
190
191         return tv;
192 }
193
194 #ifdef FIO_DEBUG_TIME
195 void fio_gettime(struct timeval *tp, void *caller)
196 #else
197 void fio_gettime(struct timeval *tp, void fio_unused *caller)
198 #endif
199 {
200         struct tv_valid *tv;
201
202 #ifdef FIO_DEBUG_TIME
203         if (!caller)
204                 caller = __builtin_return_address(0);
205
206         gtod_log_caller(caller);
207 #endif
208         if (fio_tv) {
209                 memcpy(tp, fio_tv, sizeof(*tp));
210                 return;
211         }
212
213         tv = __fio_gettime(tp);
214
215         /*
216          * If Linux is using the tsc clock on non-synced processors,
217          * sometimes time can appear to drift backwards. Fix that up.
218          */
219         if (tv) {
220                 if (tv->last_tv_valid) {
221                         if (tp->tv_sec < tv->last_tv.tv_sec)
222                                 tp->tv_sec = tv->last_tv.tv_sec;
223                         else if (tv->last_tv.tv_sec == tp->tv_sec &&
224                                  tp->tv_usec < tv->last_tv.tv_usec)
225                                 tp->tv_usec = tv->last_tv.tv_usec;
226                 }
227                 tv->last_tv_valid = 1;
228                 memcpy(&tv->last_tv, tp, sizeof(*tp));
229         }
230 }
231
232 #ifdef ARCH_HAVE_CPU_CLOCK
233 static unsigned long get_cycles_per_usec(void)
234 {
235         struct timeval s, e;
236         uint64_t c_s, c_e;
237         enum fio_cs old_cs = fio_clock_source;
238
239 #ifdef CONFIG_CLOCK_GETTIME
240         fio_clock_source = CS_CGETTIME;
241 #else
242         fio_clock_source = CS_GTOD;
243 #endif
244         __fio_gettime(&s);
245
246         c_s = get_cpu_clock();
247         do {
248                 uint64_t elapsed;
249
250                 __fio_gettime(&e);
251
252                 elapsed = utime_since(&s, &e);
253                 if (elapsed >= 1280) {
254                         c_e = get_cpu_clock();
255                         break;
256                 }
257         } while (1);
258
259         fio_clock_source = old_cs;
260         return (c_e - c_s + 127) >> 7;
261 }
262
263 #define NR_TIME_ITERS   50
264
265 static int calibrate_cpu_clock(void)
266 {
267         double delta, mean, S;
268         uint64_t avg, cycles[NR_TIME_ITERS];
269         int i, samples;
270
271         cycles[0] = get_cycles_per_usec();
272         S = delta = mean = 0.0;
273         for (i = 0; i < NR_TIME_ITERS; i++) {
274                 cycles[i] = get_cycles_per_usec();
275                 delta = cycles[i] - mean;
276                 if (delta) {
277                         mean += delta / (i + 1.0);
278                         S += delta * (cycles[i] - mean);
279                 }
280         }
281
282         /*
283          * The most common platform clock breakage is returning zero
284          * indefinitely. Check for that and return failure.
285          */
286         if (!cycles[0] && !cycles[NR_TIME_ITERS - 1])
287                 return 1;
288
289         S = sqrt(S / (NR_TIME_ITERS - 1.0));
290
291         samples = avg = 0;
292         for (i = 0; i < NR_TIME_ITERS; i++) {
293                 double this = cycles[i];
294
295                 if ((fmax(this, mean) - fmin(this, mean)) > S)
296                         continue;
297                 samples++;
298                 avg += this;
299         }
300
301         S /= (double) NR_TIME_ITERS;
302         mean /= 10.0;
303
304         for (i = 0; i < NR_TIME_ITERS; i++)
305                 dprint(FD_TIME, "cycles[%d]=%llu\n", i,
306                                         (unsigned long long) cycles[i] / 10);
307
308         avg /= samples;
309         avg = (avg + 5) / 10;
310         dprint(FD_TIME, "avg: %llu\n", (unsigned long long) avg);
311         dprint(FD_TIME, "mean=%f, S=%f\n", mean, S);
312
313         cycles_per_usec = avg;
314         inv_cycles_per_usec = 16777216UL / cycles_per_usec;
315         dprint(FD_TIME, "inv_cycles_per_usec=%lu\n", inv_cycles_per_usec);
316         return 0;
317 }
318 #else
319 static int calibrate_cpu_clock(void)
320 {
321         return 1;
322 }
323 #endif
324
325 #ifndef CONFIG_TLS_THREAD
326 void fio_local_clock_init(int is_thread)
327 {
328         struct tv_valid *t;
329
330         t = calloc(sizeof(*t), 1);
331         if (pthread_setspecific(tv_tls_key, t))
332                 log_err("fio: can't set TLS key\n");
333 }
334
335 static void kill_tv_tls_key(void *data)
336 {
337         free(data);
338 }
339 #else
340 void fio_local_clock_init(int is_thread)
341 {
342 }
343 #endif
344
345 void fio_clock_init(void)
346 {
347         if (fio_clock_source == fio_clock_source_inited)
348                 return;
349
350 #ifndef CONFIG_TLS_THREAD
351         if (pthread_key_create(&tv_tls_key, kill_tv_tls_key))
352                 log_err("fio: can't create TLS key\n");
353 #endif
354
355         fio_clock_source_inited = fio_clock_source;
356
357         if (calibrate_cpu_clock())
358                 tsc_reliable = 0;
359
360         /*
361          * If the arch sets tsc_reliable != 0, then it must be good enough
362          * to use as THE clock source. For x86 CPUs, this means the TSC
363          * runs at a constant rate and is synced across CPU cores.
364          */
365         if (tsc_reliable) {
366                 if (!fio_clock_source_set)
367                         fio_clock_source = CS_CPUCLOCK;
368         } else if (fio_clock_source == CS_CPUCLOCK)
369                 log_info("fio: clocksource=cpu may not be reliable\n");
370 }
371
372 uint64_t utime_since(struct timeval *s, struct timeval *e)
373 {
374         long sec, usec;
375         uint64_t ret;
376
377         sec = e->tv_sec - s->tv_sec;
378         usec = e->tv_usec - s->tv_usec;
379         if (sec > 0 && usec < 0) {
380                 sec--;
381                 usec += 1000000;
382         }
383
384         /*
385          * time warp bug on some kernels?
386          */
387         if (sec < 0 || (sec == 0 && usec < 0))
388                 return 0;
389
390         ret = sec * 1000000ULL + usec;
391
392         return ret;
393 }
394
395 uint64_t utime_since_now(struct timeval *s)
396 {
397         struct timeval t;
398
399         fio_gettime(&t, NULL);
400         return utime_since(s, &t);
401 }
402
403 uint64_t mtime_since(struct timeval *s, struct timeval *e)
404 {
405         long sec, usec, ret;
406
407         sec = e->tv_sec - s->tv_sec;
408         usec = e->tv_usec - s->tv_usec;
409         if (sec > 0 && usec < 0) {
410                 sec--;
411                 usec += 1000000;
412         }
413
414         if (sec < 0 || (sec == 0 && usec < 0))
415                 return 0;
416
417         sec *= 1000UL;
418         usec /= 1000UL;
419         ret = sec + usec;
420
421         return ret;
422 }
423
424 uint64_t mtime_since_now(struct timeval *s)
425 {
426         struct timeval t;
427         void *p = __builtin_return_address(0);
428
429         fio_gettime(&t, p);
430         return mtime_since(s, &t);
431 }
432
433 uint64_t time_since_now(struct timeval *s)
434 {
435         return mtime_since_now(s) / 1000;
436 }
437
438 #if defined(FIO_HAVE_CPU_AFFINITY) && defined(ARCH_HAVE_CPU_CLOCK)  && \
439     defined(CONFIG_SFAA)
440
441 #define CLOCK_ENTRIES   100000
442
443 struct clock_entry {
444         uint32_t seq;
445         uint32_t cpu;
446         uint64_t tsc;
447 };
448
449 struct clock_thread {
450         pthread_t thread;
451         int cpu;
452         pthread_mutex_t lock;
453         pthread_mutex_t started;
454         uint32_t *seq;
455         struct clock_entry *entries;
456 };
457
458 static inline uint32_t atomic32_inc_return(uint32_t *seq)
459 {
460         return 1 + __sync_fetch_and_add(seq, 1);
461 }
462
463 static void *clock_thread_fn(void *data)
464 {
465         struct clock_thread *t = data;
466         struct clock_entry *c;
467         os_cpu_mask_t cpu_mask;
468         uint32_t last_seq;
469         int i;
470
471         memset(&cpu_mask, 0, sizeof(cpu_mask));
472         fio_cpu_set(&cpu_mask, t->cpu);
473
474         if (fio_setaffinity(gettid(), cpu_mask) == -1) {
475                 log_err("clock setaffinity failed\n");
476                 return (void *) 1;
477         }
478
479         pthread_mutex_lock(&t->lock);
480         pthread_mutex_unlock(&t->started);
481
482         last_seq = 0;
483         c = &t->entries[0];
484         for (i = 0; i < CLOCK_ENTRIES; i++, c++) {
485                 uint32_t seq;
486                 uint64_t tsc;
487
488                 c->cpu = t->cpu;
489                 do {
490                         seq = atomic32_inc_return(t->seq);
491                         if (seq < last_seq)
492                                 break;
493                         tsc = get_cpu_clock();
494                 } while (seq != *t->seq);
495
496                 c->seq = seq;
497                 c->tsc = tsc;
498         }
499
500         log_info("cs: cpu%3d: %llu clocks seen\n", t->cpu,
501                 (unsigned long long) t->entries[i - 1].tsc - t->entries[0].tsc);
502
503         /*
504          * The most common platform clock breakage is returning zero
505          * indefinitely. Check for that and return failure.
506          */
507         if (!t->entries[i - 1].tsc && !t->entries[0].tsc)
508                 return (void *) 1;
509
510         return NULL;
511 }
512
513 static int clock_cmp(const void *p1, const void *p2)
514 {
515         const struct clock_entry *c1 = p1;
516         const struct clock_entry *c2 = p2;
517
518         if (c1->seq == c2->seq)
519                 log_err("cs: bug in atomic sequence!\n");
520
521         return c1->seq - c2->seq;
522 }
523
524 int fio_monotonic_clocktest(void)
525 {
526         struct clock_thread *threads;
527         unsigned int nr_cpus = cpus_online();
528         struct clock_entry *entries;
529         unsigned long tentries, failed;
530         struct clock_entry *prev, *this;
531         uint32_t seq = 0;
532         int i;
533
534         log_info("cs: reliable_tsc: %s\n", tsc_reliable ? "yes" : "no");
535
536         fio_debug |= 1U << FD_TIME;
537         calibrate_cpu_clock();
538         fio_debug &= ~(1U << FD_TIME);
539
540         threads = malloc(nr_cpus * sizeof(struct clock_thread));
541         tentries = CLOCK_ENTRIES * nr_cpus;
542         entries = malloc(tentries * sizeof(struct clock_entry));
543
544         log_info("cs: Testing %u CPUs\n", nr_cpus);
545
546         for (i = 0; i < nr_cpus; i++) {
547                 struct clock_thread *t = &threads[i];
548
549                 t->cpu = i;
550                 t->seq = &seq;
551                 t->entries = &entries[i * CLOCK_ENTRIES];
552                 pthread_mutex_init(&t->lock, NULL);
553                 pthread_mutex_init(&t->started, NULL);
554                 pthread_mutex_lock(&t->lock);
555                 pthread_create(&t->thread, NULL, clock_thread_fn, t);
556         }
557
558         for (i = 0; i < nr_cpus; i++) {
559                 struct clock_thread *t = &threads[i];
560
561                 pthread_mutex_lock(&t->started);
562         }
563
564         for (i = 0; i < nr_cpus; i++) {
565                 struct clock_thread *t = &threads[i];
566
567                 pthread_mutex_unlock(&t->lock);
568         }
569
570         for (failed = i = 0; i < nr_cpus; i++) {
571                 struct clock_thread *t = &threads[i];
572                 void *ret;
573
574                 pthread_join(t->thread, &ret);
575                 if (ret)
576                         failed++;
577         }
578         free(threads);
579
580         if (failed) {
581                 log_err("Clocksource test: %lu threads failed\n", failed);
582                 goto err;
583         }
584
585         qsort(entries, tentries, sizeof(struct clock_entry), clock_cmp);
586
587         for (failed = i = 0; i < tentries; i++) {
588                 this = &entries[i];
589
590                 if (!i) {
591                         prev = this;
592                         continue;
593                 }
594
595                 if (prev->tsc > this->tsc) {
596                         uint64_t diff = prev->tsc - this->tsc;
597
598                         log_info("cs: CPU clock mismatch (diff=%llu):\n",
599                                                 (unsigned long long) diff);
600                         log_info("\t CPU%3u: TSC=%llu, SEQ=%u\n", prev->cpu, (unsigned long long) prev->tsc, prev->seq);
601                         log_info("\t CPU%3u: TSC=%llu, SEQ=%u\n", this->cpu, (unsigned long long) this->tsc, this->seq);
602                         failed++;
603                 }
604
605                 prev = this;
606         }
607
608         if (failed)
609                 log_info("cs: Failed: %lu\n", failed);
610         else
611                 log_info("cs: Pass!\n");
612
613 err:
614         free(entries);
615         return !!failed;
616 }
617
618 #else /* defined(FIO_HAVE_CPU_AFFINITY) && defined(ARCH_HAVE_CPU_CLOCK) */
619
620 int fio_monotonic_clocktest(void)
621 {
622         log_info("cs: current platform does not support CPU clocks\n");
623         return 0;
624 }
625
626 #endif