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064af421 | 1 | /* |
4ae90ff9 | 2 | * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira Networks. |
064af421 | 3 | * |
a14bc59f BP |
4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
5 | * you may not use this file except in compliance with the License. | |
6 | * You may obtain a copy of the License at: | |
064af421 | 7 | * |
a14bc59f BP |
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
9 | * | |
10 | * Unless required by applicable law or agreed to in writing, software | |
11 | * distributed under the License is distributed on an "AS IS" BASIS, | |
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
13 | * See the License for the specific language governing permissions and | |
14 | * limitations under the License. | |
064af421 BP |
15 | */ |
16 | ||
17 | #include <config.h> | |
18 | #include "timeval.h" | |
19 | #include <assert.h> | |
20 | #include <errno.h> | |
21 | #include <poll.h> | |
22 | #include <signal.h> | |
6197af6e | 23 | #include <stdlib.h> |
064af421 BP |
24 | #include <string.h> |
25 | #include <sys/time.h> | |
26 | #include <sys/resource.h> | |
27 | #include <unistd.h> | |
28 | #include "coverage.h" | |
6197af6e | 29 | #include "dummy.h" |
064af421 | 30 | #include "fatal-signal.h" |
279c9e03 | 31 | #include "signals.h" |
6197af6e | 32 | #include "unixctl.h" |
064af421 | 33 | #include "util.h" |
064af421 | 34 | #include "vlog.h" |
5136ce49 | 35 | |
d98e6007 | 36 | VLOG_DEFINE_THIS_MODULE(timeval); |
064af421 | 37 | |
f54e56fc BP |
38 | /* The clock to use for measuring time intervals. This is CLOCK_MONOTONIC by |
39 | * preference, but on systems that don't have a monotonic clock we fall back | |
40 | * to CLOCK_REALTIME. */ | |
c73814a3 JG |
41 | static clockid_t monotonic_clock; |
42 | ||
7bc9188d BP |
43 | /* Has a timer tick occurred? |
44 | * | |
45 | * We initialize these to true to force time_init() to get called on the first | |
46 | * call to time_msec() or another function that queries the current time. */ | |
47 | static volatile sig_atomic_t wall_tick = true; | |
48 | static volatile sig_atomic_t monotonic_tick = true; | |
064af421 BP |
49 | |
50 | /* The current time, as of the last refresh. */ | |
c73814a3 JG |
51 | static struct timespec wall_time; |
52 | static struct timespec monotonic_time; | |
064af421 | 53 | |
4ae90ff9 BP |
54 | /* The monotonic time at which the time module was initialized. */ |
55 | static long long int boot_time; | |
56 | ||
6197af6e BP |
57 | /* Fixed monotonic time offset, for use by unit tests. */ |
58 | static struct timespec warp_offset; | |
59 | ||
064af421 BP |
60 | /* Time at which to die with SIGALRM (if not TIME_MIN). */ |
61 | static time_t deadline = TIME_MIN; | |
62 | ||
d6fbec6d | 63 | static void set_up_timer(void); |
58fda1da | 64 | static void set_up_signal(int flags); |
064af421 | 65 | static void sigalrm_handler(int); |
c73814a3 JG |
66 | static void refresh_wall_if_ticked(void); |
67 | static void refresh_monotonic_if_ticked(void); | |
064af421 BP |
68 | static time_t time_add(time_t, time_t); |
69 | static void block_sigalrm(sigset_t *); | |
70 | static void unblock_sigalrm(const sigset_t *); | |
959ec62e BP |
71 | static void log_poll_interval(long long int last_wakeup); |
72 | static struct rusage *get_recent_rusage(void); | |
73 | static void refresh_rusage(void); | |
6197af6e BP |
74 | static void timespec_add(struct timespec *sum, |
75 | const struct timespec *a, const struct timespec *b); | |
064af421 | 76 | |
4ae90ff9 | 77 | /* Initializes the timetracking module, if not already initialized. */ |
ff8bb7e7 | 78 | static void |
064af421 BP |
79 | time_init(void) |
80 | { | |
7bc9188d | 81 | static bool inited; |
064af421 BP |
82 | if (inited) { |
83 | return; | |
84 | } | |
7bc9188d | 85 | inited = true; |
064af421 | 86 | |
f5c6854a JP |
87 | coverage_init(); |
88 | ||
f54e56fc | 89 | if (!clock_gettime(CLOCK_MONOTONIC, &monotonic_time)) { |
c73814a3 JG |
90 | monotonic_clock = CLOCK_MONOTONIC; |
91 | } else { | |
92 | monotonic_clock = CLOCK_REALTIME; | |
93 | VLOG_DBG("monotonic timer not available"); | |
94 | } | |
95 | ||
f54e56fc BP |
96 | set_up_signal(SA_RESTART); |
97 | set_up_timer(); | |
4ae90ff9 | 98 | boot_time = time_msec(); |
c73814a3 JG |
99 | } |
100 | ||
dc81071d | 101 | static void |
58fda1da | 102 | set_up_signal(int flags) |
dc81071d BP |
103 | { |
104 | struct sigaction sa; | |
105 | ||
064af421 BP |
106 | memset(&sa, 0, sizeof sa); |
107 | sa.sa_handler = sigalrm_handler; | |
108 | sigemptyset(&sa.sa_mask); | |
dc81071d | 109 | sa.sa_flags = flags; |
279c9e03 | 110 | xsigaction(SIGALRM, &sa, NULL); |
dc81071d | 111 | } |
064af421 | 112 | |
dc81071d BP |
113 | /* Remove SA_RESTART from the flags for SIGALRM, so that any system call that |
114 | * is interrupted by the periodic timer interrupt will return EINTR instead of | |
115 | * continuing after the signal handler returns. | |
116 | * | |
117 | * time_disable_restart() and time_enable_restart() may be usefully wrapped | |
118 | * around function calls that might otherwise block forever unless interrupted | |
119 | * by a signal, e.g.: | |
120 | * | |
121 | * time_disable_restart(); | |
122 | * fcntl(fd, F_SETLKW, &lock); | |
123 | * time_enable_restart(); | |
124 | */ | |
125 | void | |
126 | time_disable_restart(void) | |
127 | { | |
7bc9188d | 128 | time_init(); |
58fda1da | 129 | set_up_signal(0); |
dc81071d BP |
130 | } |
131 | ||
132 | /* Add SA_RESTART to the flags for SIGALRM, so that any system call that | |
133 | * is interrupted by the periodic timer interrupt will continue after the | |
134 | * signal handler returns instead of returning EINTR. */ | |
135 | void | |
136 | time_enable_restart(void) | |
137 | { | |
7bc9188d | 138 | time_init(); |
58fda1da | 139 | set_up_signal(SA_RESTART); |
03fbffbd BP |
140 | } |
141 | ||
142 | static void | |
d6fbec6d | 143 | set_up_timer(void) |
03fbffbd | 144 | { |
4cfffdd8 | 145 | static timer_t timer_id; /* "static" to avoid apparent memory leak. */ |
c73814a3 JG |
146 | struct itimerspec itimer; |
147 | ||
c73814a3 | 148 | if (timer_create(monotonic_clock, NULL, &timer_id)) { |
279c9e03 | 149 | VLOG_FATAL("timer_create failed (%s)", strerror(errno)); |
c73814a3 | 150 | } |
03fbffbd | 151 | |
064af421 | 152 | itimer.it_interval.tv_sec = 0; |
c73814a3 | 153 | itimer.it_interval.tv_nsec = TIME_UPDATE_INTERVAL * 1000 * 1000; |
064af421 | 154 | itimer.it_value = itimer.it_interval; |
c73814a3 JG |
155 | |
156 | if (timer_settime(timer_id, 0, &itimer, NULL)) { | |
279c9e03 | 157 | VLOG_FATAL("timer_settime failed (%s)", strerror(errno)); |
064af421 BP |
158 | } |
159 | } | |
160 | ||
03fbffbd BP |
161 | /* Set up the interval timer, to ensure that time advances even without calling |
162 | * time_refresh(). | |
163 | * | |
164 | * A child created with fork() does not inherit the parent's interval timer, so | |
165 | * this function needs to be called from the child after fork(). */ | |
166 | void | |
167 | time_postfork(void) | |
168 | { | |
f54e56fc | 169 | time_init(); |
d6fbec6d | 170 | set_up_timer(); |
03fbffbd BP |
171 | } |
172 | ||
c73814a3 JG |
173 | static void |
174 | refresh_wall(void) | |
175 | { | |
7bc9188d | 176 | time_init(); |
c73814a3 JG |
177 | clock_gettime(CLOCK_REALTIME, &wall_time); |
178 | wall_tick = false; | |
179 | } | |
180 | ||
181 | static void | |
182 | refresh_monotonic(void) | |
183 | { | |
f54e56fc | 184 | time_init(); |
c73814a3 JG |
185 | |
186 | if (monotonic_clock == CLOCK_MONOTONIC) { | |
187 | clock_gettime(monotonic_clock, &monotonic_time); | |
188 | } else { | |
189 | refresh_wall_if_ticked(); | |
190 | monotonic_time = wall_time; | |
191 | } | |
6197af6e | 192 | timespec_add(&monotonic_time, &monotonic_time, &warp_offset); |
c73814a3 JG |
193 | |
194 | monotonic_tick = false; | |
195 | } | |
196 | ||
064af421 BP |
197 | /* Forces a refresh of the current time from the kernel. It is not usually |
198 | * necessary to call this function, since the time will be refreshed | |
199 | * automatically at least every TIME_UPDATE_INTERVAL milliseconds. */ | |
200 | void | |
201 | time_refresh(void) | |
202 | { | |
c73814a3 | 203 | wall_tick = monotonic_tick = true; |
064af421 BP |
204 | } |
205 | ||
c73814a3 | 206 | /* Returns a monotonic timer, in seconds. */ |
064af421 BP |
207 | time_t |
208 | time_now(void) | |
209 | { | |
c73814a3 JG |
210 | refresh_monotonic_if_ticked(); |
211 | return monotonic_time.tv_sec; | |
064af421 BP |
212 | } |
213 | ||
c73814a3 | 214 | /* Same as time_now() except does not write to static variables, for use in |
f54e56fc | 215 | * signal handlers. */ |
c73814a3 JG |
216 | static time_t |
217 | time_now_sig(void) | |
218 | { | |
219 | struct timespec cur_time; | |
220 | ||
221 | clock_gettime(monotonic_clock, &cur_time); | |
222 | return cur_time.tv_sec; | |
223 | } | |
224 | ||
225 | /* Returns the current time, in seconds. */ | |
226 | time_t | |
227 | time_wall(void) | |
228 | { | |
229 | refresh_wall_if_ticked(); | |
230 | return wall_time.tv_sec; | |
231 | } | |
232 | ||
233 | /* Returns a monotonic timer, in ms (within TIME_UPDATE_INTERVAL ms). */ | |
064af421 BP |
234 | long long int |
235 | time_msec(void) | |
236 | { | |
c73814a3 JG |
237 | refresh_monotonic_if_ticked(); |
238 | return timespec_to_msec(&monotonic_time); | |
239 | } | |
240 | ||
241 | /* Returns the current time, in ms (within TIME_UPDATE_INTERVAL ms). */ | |
242 | long long int | |
243 | time_wall_msec(void) | |
244 | { | |
245 | refresh_wall_if_ticked(); | |
246 | return timespec_to_msec(&wall_time); | |
247 | } | |
248 | ||
249 | /* Stores a monotonic timer, accurate within TIME_UPDATE_INTERVAL ms, into | |
250 | * '*ts'. */ | |
251 | void | |
252 | time_timespec(struct timespec *ts) | |
253 | { | |
254 | refresh_monotonic_if_ticked(); | |
255 | *ts = monotonic_time; | |
064af421 BP |
256 | } |
257 | ||
258 | /* Stores the current time, accurate within TIME_UPDATE_INTERVAL ms, into | |
c73814a3 | 259 | * '*ts'. */ |
064af421 | 260 | void |
c73814a3 | 261 | time_wall_timespec(struct timespec *ts) |
064af421 | 262 | { |
c73814a3 JG |
263 | refresh_wall_if_ticked(); |
264 | *ts = wall_time; | |
064af421 BP |
265 | } |
266 | ||
267 | /* Configures the program to die with SIGALRM 'secs' seconds from now, if | |
268 | * 'secs' is nonzero, or disables the feature if 'secs' is zero. */ | |
269 | void | |
270 | time_alarm(unsigned int secs) | |
271 | { | |
272 | sigset_t oldsigs; | |
273 | ||
274 | time_init(); | |
275 | block_sigalrm(&oldsigs); | |
276 | deadline = secs ? time_add(time_now(), secs) : TIME_MIN; | |
277 | unblock_sigalrm(&oldsigs); | |
278 | } | |
279 | ||
280 | /* Like poll(), except: | |
cee03df4 BP |
281 | * |
282 | * - The timeout is specified as an absolute time, as defined by | |
283 | * time_msec(), instead of a duration. | |
064af421 BP |
284 | * |
285 | * - On error, returns a negative error code (instead of setting errno). | |
286 | * | |
287 | * - If interrupted by a signal, retries automatically until the original | |
cee03df4 | 288 | * timeout is reached. (Because of this property, this function will |
064af421 BP |
289 | * never return -EINTR.) |
290 | * | |
291 | * - As a side effect, refreshes the current time (like time_refresh()). | |
cee03df4 BP |
292 | * |
293 | * Stores the number of milliseconds elapsed during poll in '*elapsed'. */ | |
064af421 | 294 | int |
cee03df4 BP |
295 | time_poll(struct pollfd *pollfds, int n_pollfds, long long int timeout_when, |
296 | int *elapsed) | |
064af421 BP |
297 | { |
298 | static long long int last_wakeup; | |
064af421 BP |
299 | long long int start; |
300 | sigset_t oldsigs; | |
301 | bool blocked; | |
302 | int retval; | |
303 | ||
304 | time_refresh(); | |
959ec62e | 305 | log_poll_interval(last_wakeup); |
064af421 BP |
306 | coverage_clear(); |
307 | start = time_msec(); | |
308 | blocked = false; | |
309 | for (;;) { | |
cee03df4 | 310 | long long int now = time_msec(); |
064af421 | 311 | int time_left; |
cee03df4 BP |
312 | |
313 | if (now >= timeout_when) { | |
314 | time_left = 0; | |
315 | } else if ((unsigned long long int) timeout_when - now > INT_MAX) { | |
316 | time_left = INT_MAX; | |
064af421 | 317 | } else { |
cee03df4 | 318 | time_left = timeout_when - now; |
064af421 BP |
319 | } |
320 | ||
321 | retval = poll(pollfds, n_pollfds, time_left); | |
322 | if (retval < 0) { | |
323 | retval = -errno; | |
324 | } | |
325 | time_refresh(); | |
326 | if (retval != -EINTR) { | |
327 | break; | |
328 | } | |
329 | ||
330 | if (!blocked && deadline == TIME_MIN) { | |
331 | block_sigalrm(&oldsigs); | |
332 | blocked = true; | |
333 | } | |
334 | } | |
335 | if (blocked) { | |
336 | unblock_sigalrm(&oldsigs); | |
337 | } | |
338 | last_wakeup = time_msec(); | |
959ec62e | 339 | refresh_rusage(); |
cee03df4 | 340 | *elapsed = last_wakeup - start; |
064af421 BP |
341 | return retval; |
342 | } | |
343 | ||
344 | /* Returns the sum of 'a' and 'b', with saturation on overflow or underflow. */ | |
345 | static time_t | |
346 | time_add(time_t a, time_t b) | |
347 | { | |
348 | return (a >= 0 | |
349 | ? (b > TIME_MAX - a ? TIME_MAX : a + b) | |
350 | : (b < TIME_MIN - a ? TIME_MIN : a + b)); | |
351 | } | |
352 | ||
353 | static void | |
354 | sigalrm_handler(int sig_nr) | |
355 | { | |
c73814a3 JG |
356 | wall_tick = true; |
357 | monotonic_tick = true; | |
358 | if (deadline != TIME_MIN && time_now_sig() > deadline) { | |
064af421 BP |
359 | fatal_signal_handler(sig_nr); |
360 | } | |
361 | } | |
362 | ||
363 | static void | |
c73814a3 | 364 | refresh_wall_if_ticked(void) |
064af421 | 365 | { |
c73814a3 JG |
366 | if (wall_tick) { |
367 | refresh_wall(); | |
368 | } | |
369 | } | |
370 | ||
371 | static void | |
372 | refresh_monotonic_if_ticked(void) | |
373 | { | |
c73814a3 JG |
374 | if (monotonic_tick) { |
375 | refresh_monotonic(); | |
064af421 BP |
376 | } |
377 | } | |
378 | ||
379 | static void | |
380 | block_sigalrm(sigset_t *oldsigs) | |
381 | { | |
382 | sigset_t sigalrm; | |
383 | sigemptyset(&sigalrm); | |
384 | sigaddset(&sigalrm, SIGALRM); | |
279c9e03 | 385 | xsigprocmask(SIG_BLOCK, &sigalrm, oldsigs); |
064af421 BP |
386 | } |
387 | ||
388 | static void | |
389 | unblock_sigalrm(const sigset_t *oldsigs) | |
390 | { | |
279c9e03 | 391 | xsigprocmask(SIG_SETMASK, oldsigs, NULL); |
064af421 BP |
392 | } |
393 | ||
c73814a3 JG |
394 | long long int |
395 | timespec_to_msec(const struct timespec *ts) | |
396 | { | |
397 | return (long long int) ts->tv_sec * 1000 + ts->tv_nsec / (1000 * 1000); | |
398 | } | |
399 | ||
e7cfedd6 | 400 | long long int |
064af421 BP |
401 | timeval_to_msec(const struct timeval *tv) |
402 | { | |
403 | return (long long int) tv->tv_sec * 1000 + tv->tv_usec / 1000; | |
404 | } | |
405 | ||
4ae90ff9 BP |
406 | /* Returns the monotonic time at which the "time" module was initialized, in |
407 | * milliseconds(). */ | |
408 | long long int | |
409 | time_boot_msec(void) | |
410 | { | |
411 | time_init(); | |
412 | return boot_time; | |
413 | } | |
414 | ||
279c9e03 BP |
415 | void |
416 | xgettimeofday(struct timeval *tv) | |
417 | { | |
418 | if (gettimeofday(tv, NULL) == -1) { | |
419 | VLOG_FATAL("gettimeofday failed (%s)", strerror(errno)); | |
420 | } | |
421 | } | |
422 | ||
064af421 BP |
423 | static long long int |
424 | timeval_diff_msec(const struct timeval *a, const struct timeval *b) | |
425 | { | |
426 | return timeval_to_msec(a) - timeval_to_msec(b); | |
427 | } | |
428 | ||
6197af6e BP |
429 | static void |
430 | timespec_add(struct timespec *sum, | |
431 | const struct timespec *a, | |
432 | const struct timespec *b) | |
433 | { | |
434 | struct timespec tmp; | |
435 | ||
436 | tmp.tv_sec = a->tv_sec + b->tv_sec; | |
437 | tmp.tv_nsec = a->tv_nsec + b->tv_nsec; | |
438 | if (tmp.tv_nsec >= 1000 * 1000 * 1000) { | |
439 | tmp.tv_nsec -= 1000 * 1000 * 1000; | |
440 | tmp.tv_sec++; | |
441 | } | |
442 | ||
443 | *sum = tmp; | |
444 | } | |
445 | ||
064af421 | 446 | static void |
959ec62e | 447 | log_poll_interval(long long int last_wakeup) |
064af421 BP |
448 | { |
449 | static unsigned int mean_interval; /* In 16ths of a millisecond. */ | |
450 | static unsigned int n_samples; | |
451 | ||
452 | long long int now; | |
453 | unsigned int interval; /* In 16ths of a millisecond. */ | |
454 | ||
455 | /* Compute interval from last wakeup to now in 16ths of a millisecond, | |
456 | * capped at 10 seconds (16000 in this unit). */ | |
457 | now = time_msec(); | |
458 | interval = MIN(10000, now - last_wakeup) << 4; | |
459 | ||
14865427 BP |
460 | /* Warn if we took too much time between polls: at least 50 ms and at least |
461 | * 8X the mean interval. */ | |
462 | if (n_samples > 10 && interval > mean_interval * 8 && interval > 50 * 16) { | |
959ec62e | 463 | const struct rusage *last_rusage = get_recent_rusage(); |
064af421 BP |
464 | struct rusage rusage; |
465 | ||
466 | getrusage(RUSAGE_SELF, &rusage); | |
ea8cd10d | 467 | VLOG_WARN("%lld ms poll interval (%lld ms user, %lld ms system) " |
064af421 BP |
468 | "is over %u times the weighted mean interval %u ms " |
469 | "(%u samples)", | |
ea8cd10d | 470 | now - last_wakeup, |
064af421 BP |
471 | timeval_diff_msec(&rusage.ru_utime, &last_rusage->ru_utime), |
472 | timeval_diff_msec(&rusage.ru_stime, &last_rusage->ru_stime), | |
473 | interval / mean_interval, | |
474 | (mean_interval + 8) / 16, n_samples); | |
475 | if (rusage.ru_minflt > last_rusage->ru_minflt | |
476 | || rusage.ru_majflt > last_rusage->ru_majflt) { | |
477 | VLOG_WARN("faults: %ld minor, %ld major", | |
478 | rusage.ru_minflt - last_rusage->ru_minflt, | |
479 | rusage.ru_majflt - last_rusage->ru_majflt); | |
480 | } | |
481 | if (rusage.ru_inblock > last_rusage->ru_inblock | |
482 | || rusage.ru_oublock > last_rusage->ru_oublock) { | |
483 | VLOG_WARN("disk: %ld reads, %ld writes", | |
484 | rusage.ru_inblock - last_rusage->ru_inblock, | |
485 | rusage.ru_oublock - last_rusage->ru_oublock); | |
486 | } | |
487 | if (rusage.ru_nvcsw > last_rusage->ru_nvcsw | |
488 | || rusage.ru_nivcsw > last_rusage->ru_nivcsw) { | |
489 | VLOG_WARN("context switches: %ld voluntary, %ld involuntary", | |
490 | rusage.ru_nvcsw - last_rusage->ru_nvcsw, | |
491 | rusage.ru_nivcsw - last_rusage->ru_nivcsw); | |
492 | } | |
6bc995e4 | 493 | |
d295e8e9 JP |
494 | /* Care should be taken in the value chosen for logging. Depending |
495 | * on the configuration, syslog can write changes synchronously, | |
496 | * which can cause the coverage messages to take longer to log | |
6bc995e4 JP |
497 | * than the processing delay that triggered it. */ |
498 | coverage_log(VLL_INFO, true); | |
064af421 BP |
499 | } |
500 | ||
501 | /* Update exponentially weighted moving average. With these parameters, a | |
502 | * given value decays to 1% of its value in about 100 time steps. */ | |
503 | if (n_samples++) { | |
504 | mean_interval = (mean_interval * 122 + interval * 6 + 64) / 128; | |
505 | } else { | |
506 | mean_interval = interval; | |
507 | } | |
508 | } | |
959ec62e BP |
509 | \f |
510 | /* CPU usage tracking. */ | |
511 | ||
512 | struct cpu_usage { | |
513 | long long int when; /* Time that this sample was taken. */ | |
514 | unsigned long long int cpu; /* Total user+system CPU usage when sampled. */ | |
515 | }; | |
516 | ||
517 | static struct rusage recent_rusage; | |
518 | static struct cpu_usage older = { LLONG_MIN, 0 }; | |
519 | static struct cpu_usage newer = { LLONG_MIN, 0 }; | |
520 | static int cpu_usage = -1; | |
521 | ||
522 | static struct rusage * | |
523 | get_recent_rusage(void) | |
524 | { | |
525 | return &recent_rusage; | |
526 | } | |
527 | ||
528 | static void | |
529 | refresh_rusage(void) | |
530 | { | |
531 | long long int now; | |
532 | ||
533 | now = time_msec(); | |
534 | getrusage(RUSAGE_SELF, &recent_rusage); | |
535 | ||
536 | if (now >= newer.when + 3 * 1000) { | |
537 | older = newer; | |
538 | newer.when = now; | |
539 | newer.cpu = (timeval_to_msec(&recent_rusage.ru_utime) + | |
540 | timeval_to_msec(&recent_rusage.ru_stime)); | |
541 | ||
542 | if (older.when != LLONG_MIN && newer.cpu > older.cpu) { | |
543 | unsigned int dividend = newer.cpu - older.cpu; | |
544 | unsigned int divisor = (newer.when - older.when) / 100; | |
545 | cpu_usage = divisor > 0 ? dividend / divisor : -1; | |
546 | } else { | |
547 | cpu_usage = -1; | |
548 | } | |
549 | } | |
550 | } | |
551 | ||
552 | /* Returns an estimate of this process's CPU usage, as a percentage, over the | |
553 | * past few seconds of wall-clock time. Returns -1 if no estimate is available | |
554 | * (which will happen if the process has not been running long enough to have | |
555 | * an estimate, and can happen for other reasons as well). */ | |
556 | int | |
557 | get_cpu_usage(void) | |
558 | { | |
559 | return cpu_usage; | |
560 | } | |
6197af6e BP |
561 | \f |
562 | /* Unixctl interface. */ | |
563 | ||
564 | static void | |
565 | timeval_warp_cb(struct unixctl_conn *conn, | |
566 | int argc OVS_UNUSED, const char *argv[], void *aux OVS_UNUSED) | |
567 | { | |
568 | struct timespec ts; | |
569 | int msecs; | |
570 | ||
571 | msecs = atoi(argv[1]); | |
572 | if (msecs <= 0) { | |
bde9f75d | 573 | unixctl_command_reply_error(conn, "invalid MSECS"); |
6197af6e BP |
574 | return; |
575 | } | |
576 | ||
577 | ts.tv_sec = msecs / 1000; | |
578 | ts.tv_nsec = (msecs % 1000) * 1000 * 1000; | |
579 | timespec_add(&warp_offset, &warp_offset, &ts); | |
bde9f75d | 580 | unixctl_command_reply(conn, "warped"); |
6197af6e BP |
581 | } |
582 | ||
583 | void | |
584 | timeval_dummy_register(void) | |
585 | { | |
586 | unixctl_command_register("time/warp", "MSECS", 1, 1, | |
587 | timeval_warp_cb, NULL); | |
588 | } |