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; |
09a32402 JA |
18 | #endif |
19 | static struct timeval last_tv; | |
3e488920 | 20 | static int last_tv_valid; |
02bcaa8c | 21 | |
be4ecfdf JA |
22 | static struct timeval *fio_tv; |
23 | int fio_gtod_offload = 0; | |
24 | int fio_gtod_cpu = -1; | |
783a3eb1 | 25 | static pthread_t gtod_thread; |
be4ecfdf | 26 | |
16de1bf9 | 27 | enum fio_cs fio_clock_source = FIO_PREFERRED_CLOCK_SOURCE; |
c223da83 | 28 | |
02bcaa8c JA |
29 | #ifdef FIO_DEBUG_TIME |
30 | ||
31 | #define HASH_BITS 8 | |
32 | #define HASH_SIZE (1 << HASH_BITS) | |
33 | ||
01743ee1 | 34 | static struct flist_head hash[HASH_SIZE]; |
02bcaa8c JA |
35 | static int gtod_inited; |
36 | ||
37 | struct gtod_log { | |
01743ee1 | 38 | struct flist_head list; |
02bcaa8c JA |
39 | void *caller; |
40 | unsigned long calls; | |
41 | }; | |
42 | ||
43 | static struct gtod_log *find_hash(void *caller) | |
44 | { | |
45 | unsigned long h = hash_ptr(caller, HASH_BITS); | |
01743ee1 | 46 | struct flist_head *entry; |
02bcaa8c | 47 | |
01743ee1 JA |
48 | flist_for_each(entry, &hash[h]) { |
49 | struct gtod_log *log = flist_entry(entry, struct gtod_log, | |
50 | list); | |
02bcaa8c JA |
51 | |
52 | if (log->caller == caller) | |
53 | return log; | |
54 | } | |
55 | ||
56 | return NULL; | |
57 | } | |
58 | ||
59 | static struct gtod_log *find_log(void *caller) | |
60 | { | |
61 | struct gtod_log *log = find_hash(caller); | |
62 | ||
63 | if (!log) { | |
64 | unsigned long h; | |
65 | ||
66 | log = malloc(sizeof(*log)); | |
01743ee1 | 67 | INIT_FLIST_HEAD(&log->list); |
02bcaa8c JA |
68 | log->caller = caller; |
69 | log->calls = 0; | |
70 | ||
71 | h = hash_ptr(caller, HASH_BITS); | |
01743ee1 | 72 | flist_add_tail(&log->list, &hash[h]); |
02bcaa8c JA |
73 | } |
74 | ||
75 | return log; | |
76 | } | |
77 | ||
78 | static void gtod_log_caller(void *caller) | |
79 | { | |
80 | if (gtod_inited) { | |
81 | struct gtod_log *log = find_log(caller); | |
82 | ||
83 | log->calls++; | |
84 | } | |
85 | } | |
86 | ||
87 | static void fio_exit fio_dump_gtod(void) | |
88 | { | |
89 | unsigned long total_calls = 0; | |
90 | int i; | |
91 | ||
92 | for (i = 0; i < HASH_SIZE; i++) { | |
01743ee1 | 93 | struct flist_head *entry; |
02bcaa8c JA |
94 | struct gtod_log *log; |
95 | ||
01743ee1 JA |
96 | flist_for_each(entry, &hash[i]) { |
97 | log = flist_entry(entry, struct gtod_log, list); | |
02bcaa8c | 98 | |
5ec10eaa JA |
99 | printf("function %p, calls %lu\n", log->caller, |
100 | log->calls); | |
02bcaa8c JA |
101 | total_calls += log->calls; |
102 | } | |
103 | } | |
104 | ||
105 | printf("Total %lu gettimeofday\n", total_calls); | |
106 | } | |
107 | ||
108 | static void fio_init gtod_init(void) | |
109 | { | |
110 | int i; | |
111 | ||
112 | for (i = 0; i < HASH_SIZE; i++) | |
01743ee1 | 113 | INIT_FLIST_HEAD(&hash[i]); |
02bcaa8c JA |
114 | |
115 | gtod_inited = 1; | |
116 | } | |
117 | ||
118 | #endif /* FIO_DEBUG_TIME */ | |
119 | ||
1e97cce9 | 120 | #ifdef FIO_DEBUG_TIME |
02bcaa8c | 121 | void fio_gettime(struct timeval *tp, void *caller) |
1e97cce9 JA |
122 | #else |
123 | void fio_gettime(struct timeval *tp, void fio_unused *caller) | |
124 | #endif | |
02bcaa8c JA |
125 | { |
126 | #ifdef FIO_DEBUG_TIME | |
127 | if (!caller) | |
128 | caller = __builtin_return_address(0); | |
129 | ||
130 | gtod_log_caller(caller); | |
02bcaa8c | 131 | #endif |
be4ecfdf JA |
132 | if (fio_tv) { |
133 | memcpy(tp, fio_tv, sizeof(*tp)); | |
134 | return; | |
c223da83 JA |
135 | } |
136 | ||
137 | switch (fio_clock_source) { | |
138 | case CS_GTOD: | |
02bcaa8c | 139 | gettimeofday(tp, NULL); |
c223da83 JA |
140 | break; |
141 | case CS_CGETTIME: { | |
02bcaa8c JA |
142 | struct timespec ts; |
143 | ||
5bd9c78c JA |
144 | #ifdef FIO_HAVE_CLOCK_MONOTONIC |
145 | if (clock_gettime(CLOCK_MONOTONIC, &ts) < 0) { | |
146 | #else | |
d481e006 | 147 | if (clock_gettime(CLOCK_REALTIME, &ts) < 0) { |
5bd9c78c | 148 | #endif |
c223da83 JA |
149 | log_err("fio: clock_gettime fails\n"); |
150 | assert(0); | |
02bcaa8c JA |
151 | } |
152 | ||
153 | tp->tv_sec = ts.tv_sec; | |
154 | tp->tv_usec = ts.tv_nsec / 1000; | |
c223da83 JA |
155 | break; |
156 | } | |
157 | #ifdef ARCH_HAVE_CPU_CLOCK | |
158 | case CS_CPUCLOCK: { | |
159 | unsigned long long usecs, t; | |
160 | ||
161 | t = get_cpu_clock(); | |
162 | if (t < last_cycles) { | |
163 | dprint(FD_TIME, "CPU clock going back in time\n"); | |
164 | t = last_cycles; | |
165 | } | |
166 | ||
167 | usecs = t / cycles_per_usec; | |
168 | tp->tv_sec = usecs / 1000000; | |
169 | tp->tv_usec = usecs % 1000000; | |
170 | last_cycles = t; | |
171 | break; | |
172 | } | |
173 | #endif | |
174 | default: | |
175 | log_err("fio: invalid clock source %d\n", fio_clock_source); | |
176 | break; | |
02bcaa8c | 177 | } |
3e488920 JA |
178 | |
179 | /* | |
180 | * If Linux is using the tsc clock on non-synced processors, | |
181 | * sometimes time can appear to drift backwards. Fix that up. | |
182 | */ | |
183 | if (last_tv_valid) { | |
184 | if (tp->tv_sec < last_tv.tv_sec) | |
185 | tp->tv_sec = last_tv.tv_sec; | |
186 | else if (last_tv.tv_sec == tp->tv_sec && | |
187 | tp->tv_usec < last_tv.tv_usec) | |
188 | tp->tv_usec = last_tv.tv_usec; | |
189 | } | |
190 | last_tv_valid = 1; | |
191 | memcpy(&last_tv, tp, sizeof(*tp)); | |
02bcaa8c | 192 | } |
be4ecfdf | 193 | |
09a32402 | 194 | #ifdef ARCH_HAVE_CPU_CLOCK |
c223da83 JA |
195 | static unsigned long get_cycles_per_usec(void) |
196 | { | |
197 | struct timeval s, e; | |
198 | unsigned long long c_s, c_e; | |
199 | ||
200 | gettimeofday(&s, NULL); | |
201 | c_s = get_cpu_clock(); | |
202 | do { | |
203 | unsigned long long elapsed; | |
204 | ||
205 | gettimeofday(&e, NULL); | |
206 | elapsed = utime_since(&s, &e); | |
207 | if (elapsed >= 10) { | |
208 | c_e = get_cpu_clock(); | |
209 | break; | |
210 | } | |
211 | } while (1); | |
212 | ||
213 | return c_e - c_s; | |
214 | } | |
215 | ||
09a32402 | 216 | static void calibrate_cpu_clock(void) |
c223da83 JA |
217 | { |
218 | double delta, mean, S; | |
219 | unsigned long avg, cycles[10]; | |
220 | int i, samples; | |
221 | ||
c223da83 JA |
222 | cycles[0] = get_cycles_per_usec(); |
223 | S = delta = mean = 0.0; | |
224 | for (i = 0; i < 10; i++) { | |
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 | ||
233 | S = sqrt(S / (10 - 1.0)); | |
234 | ||
235 | samples = avg = 0; | |
236 | for (i = 0; i < 10; i++) { | |
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 | ||
245 | S /= 10.0; | |
246 | mean /= 10.0; | |
247 | ||
248 | for (i = 0; i < 10; i++) | |
249 | dprint(FD_TIME, "cycles[%d]=%lu\n", i, cycles[i] / 10); | |
250 | ||
251 | avg /= (samples * 10); | |
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 | } | |
258 | #else | |
259 | static void calibrate_cpu_clock(void) | |
260 | { | |
261 | } | |
262 | #endif | |
263 | ||
264 | void fio_clock_init(void) | |
265 | { | |
266 | last_tv_valid = 0; | |
267 | calibrate_cpu_clock(); | |
c223da83 JA |
268 | } |
269 | ||
be4ecfdf JA |
270 | void fio_gtod_init(void) |
271 | { | |
272 | fio_tv = smalloc(sizeof(struct timeval)); | |
273 | assert(fio_tv); | |
274 | } | |
275 | ||
a7346816 | 276 | static void fio_gtod_update(void) |
be4ecfdf JA |
277 | { |
278 | gettimeofday(fio_tv, NULL); | |
279 | } | |
783a3eb1 JA |
280 | |
281 | static void *gtod_thread_main(void *data) | |
282 | { | |
283 | struct fio_mutex *mutex = data; | |
284 | ||
285 | fio_mutex_up(mutex); | |
286 | ||
287 | /* | |
288 | * As long as we have jobs around, update the clock. It would be nice | |
289 | * to have some way of NOT hammering that CPU with gettimeofday(), | |
290 | * but I'm not sure what to use outside of a simple CPU nop to relax | |
291 | * it - we don't want to lose precision. | |
292 | */ | |
293 | while (threads) { | |
294 | fio_gtod_update(); | |
295 | nop; | |
296 | } | |
297 | ||
298 | return NULL; | |
299 | } | |
300 | ||
301 | int fio_start_gtod_thread(void) | |
302 | { | |
303 | struct fio_mutex *mutex; | |
304 | pthread_attr_t attr; | |
305 | int ret; | |
306 | ||
307 | mutex = fio_mutex_init(0); | |
308 | if (!mutex) | |
309 | return 1; | |
310 | ||
311 | pthread_attr_init(&attr); | |
312 | pthread_attr_setstacksize(&attr, PTHREAD_STACK_MIN); | |
313 | ret = pthread_create(>od_thread, &attr, gtod_thread_main, NULL); | |
314 | pthread_attr_destroy(&attr); | |
315 | if (ret) { | |
316 | log_err("Can't create gtod thread: %s\n", strerror(ret)); | |
317 | goto err; | |
318 | } | |
319 | ||
320 | ret = pthread_detach(gtod_thread); | |
321 | if (ret) { | |
322 | log_err("Can't detatch gtod thread: %s\n", strerror(ret)); | |
323 | goto err; | |
324 | } | |
325 | ||
326 | dprint(FD_MUTEX, "wait on startup_mutex\n"); | |
327 | fio_mutex_down(mutex); | |
328 | dprint(FD_MUTEX, "done waiting on startup_mutex\n"); | |
329 | err: | |
330 | fio_mutex_remove(mutex); | |
331 | return ret; | |
332 | } |