Commit | Line | Data |
---|---|---|
02bcaa8c | 1 | /* |
f5cc024a | 2 | * Clock functions |
02bcaa8c | 3 | */ |
f5cc024a | 4 | |
02bcaa8c | 5 | #include <unistd.h> |
c223da83 | 6 | #include <math.h> |
02bcaa8c | 7 | #include <sys/time.h> |
03e20d68 | 8 | #include <time.h> |
02bcaa8c JA |
9 | |
10 | #include "fio.h" | |
be4ecfdf | 11 | #include "smalloc.h" |
02bcaa8c JA |
12 | |
13 | #include "hash.h" | |
14 | ||
09a32402 | 15 | #ifdef ARCH_HAVE_CPU_CLOCK |
c223da83 | 16 | static unsigned long cycles_per_usec; |
c223da83 | 17 | static unsigned long last_cycles; |
fa80feae | 18 | int tsc_reliable = 0; |
09a32402 JA |
19 | #endif |
20 | static struct timeval last_tv; | |
3e488920 | 21 | static int last_tv_valid; |
02bcaa8c | 22 | |
16de1bf9 | 23 | enum fio_cs fio_clock_source = FIO_PREFERRED_CLOCK_SOURCE; |
fa80feae | 24 | int fio_clock_source_set = 0; |
01423eae | 25 | enum fio_cs fio_clock_source_inited = CS_INVAL; |
c223da83 | 26 | |
02bcaa8c JA |
27 | #ifdef FIO_DEBUG_TIME |
28 | ||
29 | #define HASH_BITS 8 | |
30 | #define HASH_SIZE (1 << HASH_BITS) | |
31 | ||
01743ee1 | 32 | static struct flist_head hash[HASH_SIZE]; |
02bcaa8c JA |
33 | static int gtod_inited; |
34 | ||
35 | struct gtod_log { | |
01743ee1 | 36 | struct flist_head list; |
02bcaa8c JA |
37 | void *caller; |
38 | unsigned long calls; | |
39 | }; | |
40 | ||
41 | static struct gtod_log *find_hash(void *caller) | |
42 | { | |
43 | unsigned long h = hash_ptr(caller, HASH_BITS); | |
01743ee1 | 44 | struct flist_head *entry; |
02bcaa8c | 45 | |
01743ee1 JA |
46 | flist_for_each(entry, &hash[h]) { |
47 | struct gtod_log *log = flist_entry(entry, struct gtod_log, | |
48 | list); | |
02bcaa8c JA |
49 | |
50 | if (log->caller == caller) | |
51 | return log; | |
52 | } | |
53 | ||
54 | return NULL; | |
55 | } | |
56 | ||
57 | static struct gtod_log *find_log(void *caller) | |
58 | { | |
59 | struct gtod_log *log = find_hash(caller); | |
60 | ||
61 | if (!log) { | |
62 | unsigned long h; | |
63 | ||
64 | log = malloc(sizeof(*log)); | |
01743ee1 | 65 | INIT_FLIST_HEAD(&log->list); |
02bcaa8c JA |
66 | log->caller = caller; |
67 | log->calls = 0; | |
68 | ||
69 | h = hash_ptr(caller, HASH_BITS); | |
01743ee1 | 70 | flist_add_tail(&log->list, &hash[h]); |
02bcaa8c JA |
71 | } |
72 | ||
73 | return log; | |
74 | } | |
75 | ||
76 | static void gtod_log_caller(void *caller) | |
77 | { | |
78 | if (gtod_inited) { | |
79 | struct gtod_log *log = find_log(caller); | |
80 | ||
81 | log->calls++; | |
82 | } | |
83 | } | |
84 | ||
85 | static void fio_exit fio_dump_gtod(void) | |
86 | { | |
87 | unsigned long total_calls = 0; | |
88 | int i; | |
89 | ||
90 | for (i = 0; i < HASH_SIZE; i++) { | |
01743ee1 | 91 | struct flist_head *entry; |
02bcaa8c JA |
92 | struct gtod_log *log; |
93 | ||
01743ee1 JA |
94 | flist_for_each(entry, &hash[i]) { |
95 | log = flist_entry(entry, struct gtod_log, list); | |
02bcaa8c | 96 | |
5ec10eaa JA |
97 | printf("function %p, calls %lu\n", log->caller, |
98 | log->calls); | |
02bcaa8c JA |
99 | total_calls += log->calls; |
100 | } | |
101 | } | |
102 | ||
103 | printf("Total %lu gettimeofday\n", total_calls); | |
104 | } | |
105 | ||
106 | static void fio_init gtod_init(void) | |
107 | { | |
108 | int i; | |
109 | ||
110 | for (i = 0; i < HASH_SIZE; i++) | |
01743ee1 | 111 | INIT_FLIST_HEAD(&hash[i]); |
02bcaa8c JA |
112 | |
113 | gtod_inited = 1; | |
114 | } | |
115 | ||
116 | #endif /* FIO_DEBUG_TIME */ | |
117 | ||
1e97cce9 | 118 | #ifdef FIO_DEBUG_TIME |
02bcaa8c | 119 | void fio_gettime(struct timeval *tp, void *caller) |
1e97cce9 JA |
120 | #else |
121 | void fio_gettime(struct timeval *tp, void fio_unused *caller) | |
122 | #endif | |
02bcaa8c JA |
123 | { |
124 | #ifdef FIO_DEBUG_TIME | |
125 | if (!caller) | |
126 | caller = __builtin_return_address(0); | |
127 | ||
128 | gtod_log_caller(caller); | |
02bcaa8c | 129 | #endif |
be4ecfdf JA |
130 | if (fio_tv) { |
131 | memcpy(tp, fio_tv, sizeof(*tp)); | |
132 | return; | |
c223da83 JA |
133 | } |
134 | ||
135 | switch (fio_clock_source) { | |
136 | case CS_GTOD: | |
02bcaa8c | 137 | gettimeofday(tp, NULL); |
c223da83 JA |
138 | break; |
139 | case CS_CGETTIME: { | |
02bcaa8c JA |
140 | struct timespec ts; |
141 | ||
5bd9c78c JA |
142 | #ifdef FIO_HAVE_CLOCK_MONOTONIC |
143 | if (clock_gettime(CLOCK_MONOTONIC, &ts) < 0) { | |
144 | #else | |
d481e006 | 145 | if (clock_gettime(CLOCK_REALTIME, &ts) < 0) { |
5bd9c78c | 146 | #endif |
c223da83 JA |
147 | log_err("fio: clock_gettime fails\n"); |
148 | assert(0); | |
02bcaa8c JA |
149 | } |
150 | ||
151 | tp->tv_sec = ts.tv_sec; | |
152 | tp->tv_usec = ts.tv_nsec / 1000; | |
c223da83 JA |
153 | break; |
154 | } | |
155 | #ifdef ARCH_HAVE_CPU_CLOCK | |
156 | case CS_CPUCLOCK: { | |
157 | unsigned long long usecs, t; | |
158 | ||
159 | t = get_cpu_clock(); | |
160 | if (t < last_cycles) { | |
161 | dprint(FD_TIME, "CPU clock going back in time\n"); | |
162 | t = last_cycles; | |
163 | } | |
164 | ||
165 | usecs = t / cycles_per_usec; | |
166 | tp->tv_sec = usecs / 1000000; | |
167 | tp->tv_usec = usecs % 1000000; | |
168 | last_cycles = t; | |
169 | break; | |
170 | } | |
171 | #endif | |
172 | default: | |
173 | log_err("fio: invalid clock source %d\n", fio_clock_source); | |
174 | break; | |
02bcaa8c | 175 | } |
3e488920 JA |
176 | |
177 | /* | |
178 | * If Linux is using the tsc clock on non-synced processors, | |
179 | * sometimes time can appear to drift backwards. Fix that up. | |
180 | */ | |
181 | if (last_tv_valid) { | |
182 | if (tp->tv_sec < last_tv.tv_sec) | |
183 | tp->tv_sec = last_tv.tv_sec; | |
184 | else if (last_tv.tv_sec == tp->tv_sec && | |
185 | tp->tv_usec < last_tv.tv_usec) | |
186 | tp->tv_usec = last_tv.tv_usec; | |
187 | } | |
188 | last_tv_valid = 1; | |
189 | memcpy(&last_tv, tp, sizeof(*tp)); | |
02bcaa8c | 190 | } |
be4ecfdf | 191 | |
09a32402 | 192 | #ifdef ARCH_HAVE_CPU_CLOCK |
c223da83 JA |
193 | static unsigned long get_cycles_per_usec(void) |
194 | { | |
195 | struct timeval s, e; | |
196 | unsigned long long c_s, c_e; | |
197 | ||
198 | gettimeofday(&s, NULL); | |
199 | c_s = get_cpu_clock(); | |
200 | do { | |
201 | unsigned long long elapsed; | |
202 | ||
203 | gettimeofday(&e, NULL); | |
204 | elapsed = utime_since(&s, &e); | |
486332e5 | 205 | if (elapsed >= 1280) { |
c223da83 JA |
206 | c_e = get_cpu_clock(); |
207 | break; | |
208 | } | |
209 | } while (1); | |
210 | ||
c011000d | 211 | return (c_e - c_s + 127) >> 7; |
c223da83 JA |
212 | } |
213 | ||
fa80feae JA |
214 | #define NR_TIME_ITERS 50 |
215 | ||
09a32402 | 216 | static void calibrate_cpu_clock(void) |
c223da83 JA |
217 | { |
218 | double delta, mean, S; | |
fa80feae | 219 | unsigned long avg, cycles[NR_TIME_ITERS]; |
c223da83 JA |
220 | int i, samples; |
221 | ||
c223da83 JA |
222 | cycles[0] = get_cycles_per_usec(); |
223 | S = delta = mean = 0.0; | |
fa80feae | 224 | for (i = 0; i < NR_TIME_ITERS; i++) { |
c223da83 JA |
225 | cycles[i] = get_cycles_per_usec(); |
226 | delta = cycles[i] - mean; | |
227 | if (delta) { | |
228 | mean += delta / (i + 1.0); | |
229 | S += delta * (cycles[i] - mean); | |
230 | } | |
231 | } | |
232 | ||
fa80feae | 233 | S = sqrt(S / (NR_TIME_ITERS - 1.0)); |
c223da83 JA |
234 | |
235 | samples = avg = 0; | |
fa80feae | 236 | for (i = 0; i < NR_TIME_ITERS; i++) { |
c223da83 JA |
237 | double this = cycles[i]; |
238 | ||
03e20d68 | 239 | if ((fmax(this, mean) - fmin(this, mean)) > S) |
c223da83 JA |
240 | continue; |
241 | samples++; | |
242 | avg += this; | |
243 | } | |
244 | ||
fa80feae | 245 | S /= (double) NR_TIME_ITERS; |
89db727d | 246 | mean /= 10.0; |
c223da83 | 247 | |
fa80feae | 248 | for (i = 0; i < NR_TIME_ITERS; i++) |
c223da83 JA |
249 | dprint(FD_TIME, "cycles[%d]=%lu\n", i, cycles[i] / 10); |
250 | ||
d7abad3d JA |
251 | avg /= samples; |
252 | avg = (avg + 9) / 10; | |
c223da83 JA |
253 | dprint(FD_TIME, "avg: %lu\n", avg); |
254 | dprint(FD_TIME, "mean=%f, S=%f\n", mean, S); | |
255 | ||
256 | cycles_per_usec = avg; | |
09a32402 JA |
257 | } |
258 | #else | |
259 | static void calibrate_cpu_clock(void) | |
260 | { | |
261 | } | |
262 | #endif | |
263 | ||
264 | void fio_clock_init(void) | |
265 | { | |
01423eae JA |
266 | if (fio_clock_source == fio_clock_source_inited) |
267 | return; | |
268 | ||
09a32402 | 269 | last_tv_valid = 0; |
01423eae | 270 | fio_clock_source_inited = fio_clock_source; |
09a32402 | 271 | calibrate_cpu_clock(); |
fa80feae JA |
272 | |
273 | /* | |
274 | * If the arch sets tsc_reliable != 0, then it must be good enough | |
275 | * to use as THE clock source. For x86 CPUs, this means the TSC | |
276 | * runs at a constant rate and is synced across CPU cores. | |
277 | */ | |
278 | if (tsc_reliable) { | |
279 | if (!fio_clock_source_set) | |
280 | fio_clock_source = CS_CPUCLOCK; | |
281 | } else if (fio_clock_source == CS_CPUCLOCK) | |
282 | log_info("fio: clocksource=cpu may not be reliable\n"); | |
c223da83 JA |
283 | } |
284 | ||
39ab7da2 | 285 | unsigned long long utime_since(struct timeval *s, struct timeval *e) |
be4ecfdf | 286 | { |
39ab7da2 JA |
287 | long sec, usec; |
288 | unsigned long long ret; | |
289 | ||
290 | sec = e->tv_sec - s->tv_sec; | |
291 | usec = e->tv_usec - s->tv_usec; | |
292 | if (sec > 0 && usec < 0) { | |
293 | sec--; | |
294 | usec += 1000000; | |
295 | } | |
296 | ||
297 | /* | |
298 | * time warp bug on some kernels? | |
299 | */ | |
300 | if (sec < 0 || (sec == 0 && usec < 0)) | |
301 | return 0; | |
302 | ||
303 | ret = sec * 1000000ULL + usec; | |
304 | ||
305 | return ret; | |
be4ecfdf JA |
306 | } |
307 | ||
39ab7da2 | 308 | unsigned long long utime_since_now(struct timeval *s) |
be4ecfdf | 309 | { |
39ab7da2 JA |
310 | struct timeval t; |
311 | ||
312 | fio_gettime(&t, NULL); | |
313 | return utime_since(s, &t); | |
be4ecfdf | 314 | } |
783a3eb1 | 315 | |
39ab7da2 | 316 | unsigned long mtime_since(struct timeval *s, struct timeval *e) |
783a3eb1 | 317 | { |
39ab7da2 | 318 | long sec, usec, ret; |
783a3eb1 | 319 | |
39ab7da2 JA |
320 | sec = e->tv_sec - s->tv_sec; |
321 | usec = e->tv_usec - s->tv_usec; | |
322 | if (sec > 0 && usec < 0) { | |
323 | sec--; | |
324 | usec += 1000000; | |
783a3eb1 JA |
325 | } |
326 | ||
39ab7da2 JA |
327 | if (sec < 0 || (sec == 0 && usec < 0)) |
328 | return 0; | |
329 | ||
330 | sec *= 1000UL; | |
331 | usec /= 1000UL; | |
332 | ret = sec + usec; | |
333 | ||
334 | return ret; | |
783a3eb1 JA |
335 | } |
336 | ||
39ab7da2 | 337 | unsigned long mtime_since_now(struct timeval *s) |
783a3eb1 | 338 | { |
39ab7da2 JA |
339 | struct timeval t; |
340 | void *p = __builtin_return_address(0); | |
783a3eb1 | 341 | |
39ab7da2 JA |
342 | fio_gettime(&t, p); |
343 | return mtime_since(s, &t); | |
344 | } | |
783a3eb1 | 345 | |
39ab7da2 JA |
346 | unsigned long time_since_now(struct timeval *s) |
347 | { | |
348 | return mtime_since_now(s) / 1000; | |
783a3eb1 | 349 | } |