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