blob: 72fda3f8597e335be2fc4677a208f02db9fa62b7 [file] [log] [blame]
Jens Axboe02bcaa82006-11-24 10:42:00 +01001/*
Jens Axboef5cc0242006-11-24 10:47:40 +01002 * Clock functions
Jens Axboe02bcaa82006-11-24 10:42:00 +01003 */
Jens Axboef5cc0242006-11-24 10:47:40 +01004
Jens Axboe02bcaa82006-11-24 10:42:00 +01005#include <unistd.h>
Jens Axboec223da82010-03-24 13:23:53 +01006#include <math.h>
Jens Axboe02bcaa82006-11-24 10:42:00 +01007#include <sys/time.h>
Bruce Cran03e20d62011-01-02 20:14:54 +01008#include <time.h>
Jens Axboe02bcaa82006-11-24 10:42:00 +01009
10#include "fio.h"
Jens Axboebe4ecfd2008-12-08 14:10:52 +010011#include "smalloc.h"
Jens Axboe02bcaa82006-11-24 10:42:00 +010012
13#include "hash.h"
14
Jens Axboe09a32402010-08-15 15:01:51 -040015#ifdef ARCH_HAVE_CPU_CLOCK
Jens Axboec223da82010-03-24 13:23:53 +010016static unsigned long cycles_per_usec;
Jens Axboec223da82010-03-24 13:23:53 +010017static unsigned long last_cycles;
Jens Axboe09a32402010-08-15 15:01:51 -040018#endif
19static struct timeval last_tv;
Jens Axboe3e488922008-11-13 12:07:20 +010020static int last_tv_valid;
Jens Axboe02bcaa82006-11-24 10:42:00 +010021
Jens Axboebe4ecfd2008-12-08 14:10:52 +010022static struct timeval *fio_tv;
23int fio_gtod_offload = 0;
24int fio_gtod_cpu = -1;
25
Jens Axboec223da82010-03-24 13:23:53 +010026enum fio_cs fio_clock_source = CS_GTOD;
27
Jens Axboe02bcaa82006-11-24 10:42:00 +010028#ifdef FIO_DEBUG_TIME
29
30#define HASH_BITS 8
31#define HASH_SIZE (1 << HASH_BITS)
32
Jens Axboe01743ee2008-06-02 12:19:19 +020033static struct flist_head hash[HASH_SIZE];
Jens Axboe02bcaa82006-11-24 10:42:00 +010034static int gtod_inited;
35
36struct gtod_log {
Jens Axboe01743ee2008-06-02 12:19:19 +020037 struct flist_head list;
Jens Axboe02bcaa82006-11-24 10:42:00 +010038 void *caller;
39 unsigned long calls;
40};
41
42static struct gtod_log *find_hash(void *caller)
43{
44 unsigned long h = hash_ptr(caller, HASH_BITS);
Jens Axboe01743ee2008-06-02 12:19:19 +020045 struct flist_head *entry;
Jens Axboe02bcaa82006-11-24 10:42:00 +010046
Jens Axboe01743ee2008-06-02 12:19:19 +020047 flist_for_each(entry, &hash[h]) {
48 struct gtod_log *log = flist_entry(entry, struct gtod_log,
49 list);
Jens Axboe02bcaa82006-11-24 10:42:00 +010050
51 if (log->caller == caller)
52 return log;
53 }
54
55 return NULL;
56}
57
58static struct gtod_log *find_log(void *caller)
59{
60 struct gtod_log *log = find_hash(caller);
61
62 if (!log) {
63 unsigned long h;
64
65 log = malloc(sizeof(*log));
Jens Axboe01743ee2008-06-02 12:19:19 +020066 INIT_FLIST_HEAD(&log->list);
Jens Axboe02bcaa82006-11-24 10:42:00 +010067 log->caller = caller;
68 log->calls = 0;
69
70 h = hash_ptr(caller, HASH_BITS);
Jens Axboe01743ee2008-06-02 12:19:19 +020071 flist_add_tail(&log->list, &hash[h]);
Jens Axboe02bcaa82006-11-24 10:42:00 +010072 }
73
74 return log;
75}
76
77static void gtod_log_caller(void *caller)
78{
79 if (gtod_inited) {
80 struct gtod_log *log = find_log(caller);
81
82 log->calls++;
83 }
84}
85
86static void fio_exit fio_dump_gtod(void)
87{
88 unsigned long total_calls = 0;
89 int i;
90
91 for (i = 0; i < HASH_SIZE; i++) {
Jens Axboe01743ee2008-06-02 12:19:19 +020092 struct flist_head *entry;
Jens Axboe02bcaa82006-11-24 10:42:00 +010093 struct gtod_log *log;
94
Jens Axboe01743ee2008-06-02 12:19:19 +020095 flist_for_each(entry, &hash[i]) {
96 log = flist_entry(entry, struct gtod_log, list);
Jens Axboe02bcaa82006-11-24 10:42:00 +010097
Jens Axboe5ec10ea2008-03-06 15:42:00 +010098 printf("function %p, calls %lu\n", log->caller,
99 log->calls);
Jens Axboe02bcaa82006-11-24 10:42:00 +0100100 total_calls += log->calls;
101 }
102 }
103
104 printf("Total %lu gettimeofday\n", total_calls);
105}
106
107static void fio_init gtod_init(void)
108{
109 int i;
110
111 for (i = 0; i < HASH_SIZE; i++)
Jens Axboe01743ee2008-06-02 12:19:19 +0200112 INIT_FLIST_HEAD(&hash[i]);
Jens Axboe02bcaa82006-11-24 10:42:00 +0100113
114 gtod_inited = 1;
115}
116
117#endif /* FIO_DEBUG_TIME */
118
Jens Axboe1e97cce2006-12-05 11:44:16 +0100119#ifdef FIO_DEBUG_TIME
Jens Axboe02bcaa82006-11-24 10:42:00 +0100120void fio_gettime(struct timeval *tp, void *caller)
Jens Axboe1e97cce2006-12-05 11:44:16 +0100121#else
122void fio_gettime(struct timeval *tp, void fio_unused *caller)
123#endif
Jens Axboe02bcaa82006-11-24 10:42:00 +0100124{
125#ifdef FIO_DEBUG_TIME
126 if (!caller)
127 caller = __builtin_return_address(0);
128
129 gtod_log_caller(caller);
Jens Axboe02bcaa82006-11-24 10:42:00 +0100130#endif
Jens Axboebe4ecfd2008-12-08 14:10:52 +0100131 if (fio_tv) {
132 memcpy(tp, fio_tv, sizeof(*tp));
133 return;
Jens Axboec223da82010-03-24 13:23:53 +0100134 }
135
136 switch (fio_clock_source) {
137 case CS_GTOD:
Jens Axboe02bcaa82006-11-24 10:42:00 +0100138 gettimeofday(tp, NULL);
Jens Axboec223da82010-03-24 13:23:53 +0100139 break;
140 case CS_CGETTIME: {
Jens Axboe02bcaa82006-11-24 10:42:00 +0100141 struct timespec ts;
142
Jens Axboed481e002009-12-04 09:56:32 +0100143 if (clock_gettime(CLOCK_REALTIME, &ts) < 0) {
Jens Axboec223da82010-03-24 13:23:53 +0100144 log_err("fio: clock_gettime fails\n");
145 assert(0);
Jens Axboe02bcaa82006-11-24 10:42:00 +0100146 }
147
148 tp->tv_sec = ts.tv_sec;
149 tp->tv_usec = ts.tv_nsec / 1000;
Jens Axboec223da82010-03-24 13:23:53 +0100150 break;
151 }
152#ifdef ARCH_HAVE_CPU_CLOCK
153 case CS_CPUCLOCK: {
154 unsigned long long usecs, t;
155
156 t = get_cpu_clock();
157 if (t < last_cycles) {
158 dprint(FD_TIME, "CPU clock going back in time\n");
159 t = last_cycles;
160 }
161
162 usecs = t / cycles_per_usec;
163 tp->tv_sec = usecs / 1000000;
164 tp->tv_usec = usecs % 1000000;
165 last_cycles = t;
166 break;
167 }
168#endif
169 default:
170 log_err("fio: invalid clock source %d\n", fio_clock_source);
171 break;
Jens Axboe02bcaa82006-11-24 10:42:00 +0100172 }
Jens Axboe3e488922008-11-13 12:07:20 +0100173
174 /*
175 * If Linux is using the tsc clock on non-synced processors,
176 * sometimes time can appear to drift backwards. Fix that up.
177 */
178 if (last_tv_valid) {
179 if (tp->tv_sec < last_tv.tv_sec)
180 tp->tv_sec = last_tv.tv_sec;
181 else if (last_tv.tv_sec == tp->tv_sec &&
182 tp->tv_usec < last_tv.tv_usec)
183 tp->tv_usec = last_tv.tv_usec;
184 }
185 last_tv_valid = 1;
186 memcpy(&last_tv, tp, sizeof(*tp));
Jens Axboe02bcaa82006-11-24 10:42:00 +0100187}
Jens Axboebe4ecfd2008-12-08 14:10:52 +0100188
Jens Axboe09a32402010-08-15 15:01:51 -0400189#ifdef ARCH_HAVE_CPU_CLOCK
Jens Axboec223da82010-03-24 13:23:53 +0100190static unsigned long get_cycles_per_usec(void)
191{
192 struct timeval s, e;
193 unsigned long long c_s, c_e;
194
195 gettimeofday(&s, NULL);
196 c_s = get_cpu_clock();
197 do {
198 unsigned long long elapsed;
199
200 gettimeofday(&e, NULL);
201 elapsed = utime_since(&s, &e);
202 if (elapsed >= 10) {
203 c_e = get_cpu_clock();
204 break;
205 }
206 } while (1);
207
208 return c_e - c_s;
209}
210
Jens Axboe09a32402010-08-15 15:01:51 -0400211static void calibrate_cpu_clock(void)
Jens Axboec223da82010-03-24 13:23:53 +0100212{
213 double delta, mean, S;
214 unsigned long avg, cycles[10];
215 int i, samples;
216
Jens Axboec223da82010-03-24 13:23:53 +0100217 cycles[0] = get_cycles_per_usec();
218 S = delta = mean = 0.0;
219 for (i = 0; i < 10; i++) {
220 cycles[i] = get_cycles_per_usec();
221 delta = cycles[i] - mean;
222 if (delta) {
223 mean += delta / (i + 1.0);
224 S += delta * (cycles[i] - mean);
225 }
226 }
227
228 S = sqrt(S / (10 - 1.0));
229
230 samples = avg = 0;
231 for (i = 0; i < 10; i++) {
232 double this = cycles[i];
233
Bruce Cran03e20d62011-01-02 20:14:54 +0100234 if ((fmax(this, mean) - fmin(this, mean)) > S)
Jens Axboec223da82010-03-24 13:23:53 +0100235 continue;
236 samples++;
237 avg += this;
238 }
239
240 S /= 10.0;
241 mean /= 10.0;
242
243 for (i = 0; i < 10; i++)
244 dprint(FD_TIME, "cycles[%d]=%lu\n", i, cycles[i] / 10);
245
246 avg /= (samples * 10);
247 dprint(FD_TIME, "avg: %lu\n", avg);
248 dprint(FD_TIME, "mean=%f, S=%f\n", mean, S);
249
250 cycles_per_usec = avg;
Jens Axboe09a32402010-08-15 15:01:51 -0400251
252}
253#else
254static void calibrate_cpu_clock(void)
255{
256}
257#endif
258
259void fio_clock_init(void)
260{
261 last_tv_valid = 0;
262 calibrate_cpu_clock();
Jens Axboec223da82010-03-24 13:23:53 +0100263}
264
Jens Axboebe4ecfd2008-12-08 14:10:52 +0100265void fio_gtod_init(void)
266{
267 fio_tv = smalloc(sizeof(struct timeval));
268 assert(fio_tv);
269}
270
271void fio_gtod_update(void)
272{
273 gettimeofday(fio_tv, NULL);
274}