X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;ds=inline;f=lib%2Ftimeval.c;h=3d339e4ecdb988b4f02bbdc717e72038f1d692af;hb=1d446463ea3707ee609ea45f0cd2714aa7f5bfc6;hp=8097ce806b413f21e429ebbca4fcef01555c6a94;hpb=4ae90ff9e2011d54f52043a55707d16c8a9a258e;p=openvswitch diff --git a/lib/timeval.c b/lib/timeval.c index 8097ce80..3d339e4e 100644 --- a/lib/timeval.c +++ b/lib/timeval.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira Networks. + * Copyright (c) 2008, 2009, 2010, 2011, 2012 Nicira, Inc. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -40,7 +40,7 @@ VLOG_DEFINE_THIS_MODULE(timeval); * to CLOCK_REALTIME. */ static clockid_t monotonic_clock; -/* Has a timer tick occurred? +/* Has a timer tick occurred? Only relevant if CACHE_TIME is 1. * * We initialize these to true to force time_init() to get called on the first * call to time_msec() or another function that queries the current time. */ @@ -54,8 +54,9 @@ static struct timespec monotonic_time; /* The monotonic time at which the time module was initialized. */ static long long int boot_time; -/* Fixed monotonic time offset, for use by unit tests. */ -static struct timespec warp_offset; +/* features for use by unit tests. */ +static struct timespec warp_offset; /* Offset added to monotonic_time. */ +static bool time_stopped; /* Disables real-time updates, if true. */ /* Time at which to die with SIGALRM (if not TIME_MIN). */ static time_t deadline = TIME_MIN; @@ -93,8 +94,11 @@ time_init(void) VLOG_DBG("monotonic timer not available"); } - set_up_signal(SA_RESTART); - set_up_timer(); + if (CACHE_TIME) { + set_up_signal(SA_RESTART); + set_up_timer(); + } + boot_time = time_msec(); } @@ -167,7 +171,16 @@ void time_postfork(void) { time_init(); - set_up_timer(); + + if (CACHE_TIME) { + set_up_timer(); + } else { + /* If we are not caching kernel time, the only reason the timer should + * exist is if time_alarm() was called and deadline is set */ + if (deadline != TIME_MIN) { + set_up_timer(); + } + } } static void @@ -183,20 +196,24 @@ refresh_monotonic(void) { time_init(); - if (monotonic_clock == CLOCK_MONOTONIC) { - clock_gettime(monotonic_clock, &monotonic_time); - } else { - refresh_wall_if_ticked(); - monotonic_time = wall_time; - } - timespec_add(&monotonic_time, &monotonic_time, &warp_offset); + if (!time_stopped) { + if (monotonic_clock == CLOCK_MONOTONIC) { + clock_gettime(monotonic_clock, &monotonic_time); + } else { + refresh_wall_if_ticked(); + monotonic_time = wall_time; + } + timespec_add(&monotonic_time, &monotonic_time, &warp_offset); - monotonic_tick = false; + monotonic_tick = false; + } } /* Forces a refresh of the current time from the kernel. It is not usually * necessary to call this function, since the time will be refreshed - * automatically at least every TIME_UPDATE_INTERVAL milliseconds. */ + * automatically at least every TIME_UPDATE_INTERVAL milliseconds. If + * CACHE_TIME is 0, we will always refresh the current time so this + * function has no effect. */ void time_refresh(void) { @@ -272,9 +289,17 @@ time_alarm(unsigned int secs) sigset_t oldsigs; time_init(); + block_sigalrm(&oldsigs); deadline = secs ? time_add(time_now(), secs) : TIME_MIN; unblock_sigalrm(&oldsigs); + + if (!CACHE_TIME) { + /* If we aren't timing the gaps between kernel time refreshes we need to + * to start the timer up now */ + set_up_signal(SA_RESTART); + set_up_timer(); + } } /* Like poll(), except: @@ -363,7 +388,7 @@ sigalrm_handler(int sig_nr) static void refresh_wall_if_ticked(void) { - if (wall_tick) { + if (!CACHE_TIME || wall_tick) { refresh_wall(); } } @@ -371,7 +396,7 @@ refresh_wall_if_ticked(void) static void refresh_monotonic_if_ticked(void) { - if (monotonic_tick) { + if (!CACHE_TIME || monotonic_tick) { refresh_monotonic(); } } @@ -460,42 +485,43 @@ log_poll_interval(long long int last_wakeup) /* Warn if we took too much time between polls: at least 50 ms and at least * 8X the mean interval. */ if (n_samples > 10 && interval > mean_interval * 8 && interval > 50 * 16) { - const struct rusage *last_rusage = get_recent_rusage(); - struct rusage rusage; - - getrusage(RUSAGE_SELF, &rusage); - VLOG_WARN("%lld ms poll interval (%lld ms user, %lld ms system) " - "is over %u times the weighted mean interval %u ms " - "(%u samples)", - now - last_wakeup, - timeval_diff_msec(&rusage.ru_utime, &last_rusage->ru_utime), - timeval_diff_msec(&rusage.ru_stime, &last_rusage->ru_stime), - interval / mean_interval, - (mean_interval + 8) / 16, n_samples); - if (rusage.ru_minflt > last_rusage->ru_minflt - || rusage.ru_majflt > last_rusage->ru_majflt) { - VLOG_WARN("faults: %ld minor, %ld major", - rusage.ru_minflt - last_rusage->ru_minflt, - rusage.ru_majflt - last_rusage->ru_majflt); + static struct vlog_rate_limit rl = VLOG_RATE_LIMIT_INIT(1, 3); + + if (!VLOG_DROP_WARN(&rl)) { + const struct rusage *last_rusage = get_recent_rusage(); + struct rusage rusage; + + getrusage(RUSAGE_SELF, &rusage); + VLOG_WARN("%lld ms poll interval (%lld ms user, %lld ms system) " + "is over %u times the weighted mean interval %u ms " + "(%u samples)", + now - last_wakeup, + timeval_diff_msec(&rusage.ru_utime, + &last_rusage->ru_utime), + timeval_diff_msec(&rusage.ru_stime, + &last_rusage->ru_stime), + interval / mean_interval, + (mean_interval + 8) / 16, n_samples); + if (rusage.ru_minflt > last_rusage->ru_minflt + || rusage.ru_majflt > last_rusage->ru_majflt) { + VLOG_WARN("faults: %ld minor, %ld major", + rusage.ru_minflt - last_rusage->ru_minflt, + rusage.ru_majflt - last_rusage->ru_majflt); + } + if (rusage.ru_inblock > last_rusage->ru_inblock + || rusage.ru_oublock > last_rusage->ru_oublock) { + VLOG_WARN("disk: %ld reads, %ld writes", + rusage.ru_inblock - last_rusage->ru_inblock, + rusage.ru_oublock - last_rusage->ru_oublock); + } + if (rusage.ru_nvcsw > last_rusage->ru_nvcsw + || rusage.ru_nivcsw > last_rusage->ru_nivcsw) { + VLOG_WARN("context switches: %ld voluntary, %ld involuntary", + rusage.ru_nvcsw - last_rusage->ru_nvcsw, + rusage.ru_nivcsw - last_rusage->ru_nivcsw); + } } - if (rusage.ru_inblock > last_rusage->ru_inblock - || rusage.ru_oublock > last_rusage->ru_oublock) { - VLOG_WARN("disk: %ld reads, %ld writes", - rusage.ru_inblock - last_rusage->ru_inblock, - rusage.ru_oublock - last_rusage->ru_oublock); - } - if (rusage.ru_nvcsw > last_rusage->ru_nvcsw - || rusage.ru_nivcsw > last_rusage->ru_nivcsw) { - VLOG_WARN("context switches: %ld voluntary, %ld involuntary", - rusage.ru_nvcsw - last_rusage->ru_nvcsw, - rusage.ru_nivcsw - last_rusage->ru_nivcsw); - } - - /* Care should be taken in the value chosen for logging. Depending - * on the configuration, syslog can write changes synchronously, - * which can cause the coverage messages to take longer to log - * than the processing delay that triggered it. */ - coverage_log(VLL_INFO, true); + coverage_log(); } /* Update exponentially weighted moving average. With these parameters, a @@ -561,6 +587,22 @@ get_cpu_usage(void) /* Unixctl interface. */ +/* "time/stop" stops the monotonic time returned by e.g. time_msec() from + * advancing, except due to later calls to "time/warp". */ +static void +timeval_stop_cb(struct unixctl_conn *conn, + int argc OVS_UNUSED, const char *argv[] OVS_UNUSED, + void *aux OVS_UNUSED) +{ + time_stopped = true; + unixctl_command_reply(conn, NULL); +} + +/* "time/warp MSECS" advances the current monotonic time by the specified + * number of milliseconds. Unless "time/stop" has also been executed, the + * monotonic clock continues to tick forward at the normal rate afterward. + * + * Does not affect wall clock readings. */ static void timeval_warp_cb(struct unixctl_conn *conn, int argc OVS_UNUSED, const char *argv[], void *aux OVS_UNUSED) @@ -570,19 +612,21 @@ timeval_warp_cb(struct unixctl_conn *conn, msecs = atoi(argv[1]); if (msecs <= 0) { - unixctl_command_reply(conn, 501, "invalid MSECS"); + unixctl_command_reply_error(conn, "invalid MSECS"); return; } ts.tv_sec = msecs / 1000; ts.tv_nsec = (msecs % 1000) * 1000 * 1000; timespec_add(&warp_offset, &warp_offset, &ts); - unixctl_command_reply(conn, 200, "warped"); + timespec_add(&monotonic_time, &monotonic_time, &ts); + unixctl_command_reply(conn, "warped"); } void timeval_dummy_register(void) { + unixctl_command_register("time/stop", "", 0, 0, timeval_stop_cb, NULL); unixctl_command_register("time/warp", "MSECS", 1, 1, timeval_warp_cb, NULL); }