#include <config.h>
#include "timeval.h"
#include <errno.h>
-#if HAVE_EXECINFO_H
-#include <execinfo.h>
-#endif
#include <poll.h>
+#include <pthread.h>
#include <signal.h>
#include <stdlib.h>
#include <string.h>
#include "fatal-signal.h"
#include "hash.h"
#include "hmap.h"
+#include "ovs-thread.h"
#include "signals.h"
#include "unixctl.h"
#include "util.h"
VLOG_DEFINE_THIS_MODULE(timeval);
-/* The clock to use for measuring time intervals. This is CLOCK_MONOTONIC by
- * preference, but on systems that don't have a monotonic clock we fall back
- * to CLOCK_REALTIME. */
-static clockid_t monotonic_clock;
+struct clock {
+ clockid_t id; /* CLOCK_MONOTONIC or CLOCK_REALTIME. */
+ struct ovs_rwlock rwlock; /* Mutual exclusion for 'cache'. */
-/* Has a timer tick occurred? Only relevant if CACHE_TIME is true.
- *
- * 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. */
-static volatile sig_atomic_t wall_tick = true;
-static volatile sig_atomic_t monotonic_tick = true;
+ /* Features for use by unit tests. Protected by 'rwlock'. */
+ struct timespec warp; /* Offset added for unit tests. */
+ bool stopped; /* Disables real-time updates if true. */
+
+ /* Relevant only if CACHE_TIME is true. */
+ volatile sig_atomic_t tick; /* Has the timer ticked? Set by signal. */
+ struct timespec cache; /* Last time read from kernel. */
+};
-/* The current time, as of the last refresh. */
-static struct timespec wall_time;
-static struct timespec monotonic_time;
+/* Our clocks. */
+static struct clock monotonic_clock; /* CLOCK_MONOTONIC, if available. */
+static struct clock wall_clock; /* CLOCK_REALTIME. */
/* The monotonic time at which the time module was initialized. */
static long long int boot_time;
-/* 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 in milliseconds at which to die with SIGALRM (if not LLONG_MAX). */
+/* Monotonic time in milliseconds at which to die with SIGALRM (if not
+ * LLONG_MAX). */
static long long int deadline = LLONG_MAX;
-struct trace {
- void *backtrace[32]; /* Populated by backtrace(). */
- size_t n_frames; /* Number of frames in 'backtrace'. */
-
- /* format_backtraces() helper data. */
- struct hmap_node node;
- size_t count;
-};
-
-#define MAX_TRACES 50
-static struct trace traces[MAX_TRACES];
-static size_t trace_head = 0;
+/* Monotonic time, in milliseconds, at which the last call to time_poll() woke
+ * up. */
+DEFINE_PER_THREAD_DATA(long long int, last_wakeup, 0);
static void set_up_timer(void);
static void set_up_signal(int flags);
static void sigalrm_handler(int);
-static void refresh_wall_if_ticked(void);
-static void refresh_monotonic_if_ticked(void);
static void block_sigalrm(sigset_t *);
static void unblock_sigalrm(const sigset_t *);
static void log_poll_interval(long long int last_wakeup);
static void refresh_rusage(void);
static void timespec_add(struct timespec *sum,
const struct timespec *a, const struct timespec *b);
-static unixctl_cb_func backtrace_cb;
-
-#ifndef HAVE_EXECINFO_H
-#define HAVE_EXECINFO_H 0
-static int
-backtrace(void **buffer OVS_UNUSED, int size OVS_UNUSED)
-{
- NOT_REACHED();
-}
-
-static char **
-backtrace_symbols(void *const *buffer OVS_UNUSED, int size OVS_UNUSED)
+static void
+init_clock(struct clock *c, clockid_t id)
{
- NOT_REACHED();
+ memset(c, 0, sizeof *c);
+ c->id = id;
+ ovs_rwlock_init(&c->rwlock);
+ xclock_gettime(c->id, &c->cache);
}
-#endif
-/* Initializes the timetracking module, if not already initialized. */
static void
-time_init(void)
+do_init_time(void)
{
- static bool inited;
-
- if (inited) {
- return;
- }
- inited = true;
-
- /* The implementation of backtrace() in glibc does some one time
- * initialization which is not signal safe. This can cause deadlocks if
- * run from the signal handler. As a workaround, force the initialization
- * to happen here. */
- if (HAVE_EXECINFO_H) {
- void *bt[1];
-
- backtrace(bt, ARRAY_SIZE(bt));
- }
-
- memset(traces, 0, sizeof traces);
-
- if (HAVE_EXECINFO_H && CACHE_TIME) {
- unixctl_command_register("backtrace", "", 0, 0, backtrace_cb, NULL);
- }
+ struct timespec ts;
coverage_init();
- if (!clock_gettime(CLOCK_MONOTONIC, &monotonic_time)) {
- monotonic_clock = CLOCK_MONOTONIC;
- } else {
- monotonic_clock = CLOCK_REALTIME;
- VLOG_DBG("monotonic timer not available");
- }
+ init_clock(&monotonic_clock, (!clock_gettime(CLOCK_MONOTONIC, &ts)
+ ? CLOCK_MONOTONIC
+ : CLOCK_REALTIME));
+ init_clock(&wall_clock, CLOCK_REALTIME);
+ boot_time = timespec_to_msec(&monotonic_clock.cache);
set_up_signal(SA_RESTART);
set_up_timer();
+}
- boot_time = time_msec();
+/* Initializes the timetracking module, if not already initialized. */
+static void
+time_init(void)
+{
+ static pthread_once_t once = PTHREAD_ONCE_INIT;
+ pthread_once(&once, do_init_time);
}
static void
xsigaction(SIGALRM, &sa, NULL);
}
-/* Remove SA_RESTART from the flags for SIGALRM, so that any system call that
- * is interrupted by the periodic timer interrupt will return EINTR instead of
- * continuing after the signal handler returns.
- *
- * time_disable_restart() and time_enable_restart() may be usefully wrapped
- * around function calls that might otherwise block forever unless interrupted
- * by a signal, e.g.:
- *
- * time_disable_restart();
- * fcntl(fd, F_SETLKW, &lock);
- * time_enable_restart();
- */
-void
-time_disable_restart(void)
-{
- time_init();
- set_up_signal(0);
-}
-
-/* Add SA_RESTART to the flags for SIGALRM, so that any system call that
- * is interrupted by the periodic timer interrupt will continue after the
- * signal handler returns instead of returning EINTR. */
-void
-time_enable_restart(void)
-{
- time_init();
- set_up_signal(SA_RESTART);
-}
-
static void
set_up_timer(void)
{
return;
}
- if (timer_create(monotonic_clock, NULL, &timer_id)) {
- VLOG_FATAL("timer_create failed (%s)", strerror(errno));
+ if (timer_create(monotonic_clock.id, NULL, &timer_id)) {
+ VLOG_FATAL("timer_create failed (%s)", ovs_strerror(errno));
}
itimer.it_interval.tv_sec = 0;
itimer.it_value = itimer.it_interval;
if (timer_settime(timer_id, 0, &itimer, NULL)) {
- VLOG_FATAL("timer_settime failed (%s)", strerror(errno));
+ VLOG_FATAL("timer_settime failed (%s)", ovs_strerror(errno));
}
}
void
time_postfork(void)
{
+ assert_single_threaded();
time_init();
set_up_timer();
}
-static void
-refresh_wall(void)
+/* 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. If
+ * CACHE_TIME is false, we will always refresh the current time so this
+ * function has no effect. */
+void
+time_refresh(void)
{
- time_init();
- clock_gettime(CLOCK_REALTIME, &wall_time);
- wall_tick = false;
+ monotonic_clock.tick = wall_clock.tick = true;
}
static void
-refresh_monotonic(void)
+time_timespec__(struct clock *c, struct timespec *ts)
{
time_init();
-
- if (!time_stopped) {
- if (monotonic_clock == CLOCK_MONOTONIC) {
- clock_gettime(monotonic_clock, &monotonic_time);
- } else {
- refresh_wall_if_ticked();
- monotonic_time = wall_time;
+ for (;;) {
+ /* Use the cached time by preference, but fall through if there's been
+ * a clock tick. */
+ ovs_rwlock_rdlock(&c->rwlock);
+ if (c->stopped || !c->tick) {
+ timespec_add(ts, &c->cache, &c->warp);
+ ovs_rwlock_unlock(&c->rwlock);
+ return;
}
- timespec_add(&monotonic_time, &monotonic_time, &warp_offset);
+ ovs_rwlock_unlock(&c->rwlock);
- monotonic_tick = false;
+ /* Refresh the cache. */
+ ovs_rwlock_wrlock(&c->rwlock);
+ if (c->tick) {
+ c->tick = false;
+ xclock_gettime(c->id, &c->cache);
+ }
+ ovs_rwlock_unlock(&c->rwlock);
}
}
-/* 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. If
- * CACHE_TIME is false, we will always refresh the current time so this
- * function has no effect. */
+/* Stores a monotonic timer, accurate within TIME_UPDATE_INTERVAL ms, into
+ * '*ts'. */
void
-time_refresh(void)
+time_timespec(struct timespec *ts)
{
- wall_tick = monotonic_tick = true;
+ time_timespec__(&monotonic_clock, ts);
+}
+
+/* Stores the current time, accurate within TIME_UPDATE_INTERVAL ms, into
+ * '*ts'. */
+void
+time_wall_timespec(struct timespec *ts)
+{
+ time_timespec__(&wall_clock, ts);
+}
+
+static time_t
+time_sec__(struct clock *c)
+{
+ struct timespec ts;
+
+ time_timespec__(c, &ts);
+ return ts.tv_sec;
}
/* Returns a monotonic timer, in seconds. */
time_t
time_now(void)
{
- refresh_monotonic_if_ticked();
- return monotonic_time.tv_sec;
+ return time_sec__(&monotonic_clock);
}
/* Returns the current time, in seconds. */
time_t
time_wall(void)
{
- refresh_wall_if_ticked();
- return wall_time.tv_sec;
+ return time_sec__(&wall_clock);
+}
+
+static long long int
+time_msec__(struct clock *c)
+{
+ struct timespec ts;
+
+ time_timespec__(c, &ts);
+ return timespec_to_msec(&ts);
}
/* Returns a monotonic timer, in ms (within TIME_UPDATE_INTERVAL ms). */
long long int
time_msec(void)
{
- refresh_monotonic_if_ticked();
- return timespec_to_msec(&monotonic_time);
+ return time_msec__(&monotonic_clock);
}
/* Returns the current time, in ms (within TIME_UPDATE_INTERVAL ms). */
long long int
time_wall_msec(void)
{
- refresh_wall_if_ticked();
- return timespec_to_msec(&wall_time);
-}
-
-/* Stores a monotonic timer, accurate within TIME_UPDATE_INTERVAL ms, into
- * '*ts'. */
-void
-time_timespec(struct timespec *ts)
-{
- refresh_monotonic_if_ticked();
- *ts = monotonic_time;
-}
-
-/* Stores the current time, accurate within TIME_UPDATE_INTERVAL ms, into
- * '*ts'. */
-void
-time_wall_timespec(struct timespec *ts)
-{
- refresh_wall_if_ticked();
- *ts = wall_time;
+ return time_msec__(&wall_clock);
}
/* Configures the program to die with SIGALRM 'secs' seconds from now, if
long long int now;
long long int msecs;
- sigset_t oldsigs;
-
+ assert_single_threaded();
time_init();
time_refresh();
now = time_msec();
msecs = secs * 1000LL;
-
- block_sigalrm(&oldsigs);
deadline = now < LLONG_MAX - msecs ? now + msecs : LLONG_MAX;
- unblock_sigalrm(&oldsigs);
}
/* Like poll(), except:
time_poll(struct pollfd *pollfds, int n_pollfds, long long int timeout_when,
int *elapsed)
{
- static long long int last_wakeup = 0;
+ long long int *last_wakeup = last_wakeup_get();
long long int start;
sigset_t oldsigs;
bool blocked;
int retval;
+ time_init();
time_refresh();
- if (last_wakeup) {
- log_poll_interval(last_wakeup);
+ if (*last_wakeup) {
+ log_poll_interval(*last_wakeup);
}
coverage_clear();
start = time_msec();
if (blocked) {
unblock_sigalrm(&oldsigs);
}
- last_wakeup = time_msec();
+ *last_wakeup = time_msec();
refresh_rusage();
- *elapsed = last_wakeup - start;
+ *elapsed = *last_wakeup - start;
return retval;
}
static void
sigalrm_handler(int sig_nr OVS_UNUSED)
{
- wall_tick = true;
- monotonic_tick = true;
-
- if (HAVE_EXECINFO_H && CACHE_TIME) {
- struct trace *trace = &traces[trace_head];
-
- trace->n_frames = backtrace(trace->backtrace,
- ARRAY_SIZE(trace->backtrace));
- trace_head = (trace_head + 1) % MAX_TRACES;
- }
-}
-
-static void
-refresh_wall_if_ticked(void)
-{
- if (!CACHE_TIME || wall_tick) {
- refresh_wall();
- }
-}
-
-static void
-refresh_monotonic_if_ticked(void)
-{
- if (!CACHE_TIME || monotonic_tick) {
- refresh_monotonic();
- }
+ monotonic_clock.tick = wall_clock.tick = true;
}
static void
sigset_t sigalrm;
sigemptyset(&sigalrm);
sigaddset(&sigalrm, SIGALRM);
- xsigprocmask(SIG_BLOCK, &sigalrm, oldsigs);
+ xpthread_sigmask(SIG_BLOCK, &sigalrm, oldsigs);
}
static void
unblock_sigalrm(const sigset_t *oldsigs)
{
- xsigprocmask(SIG_SETMASK, oldsigs, NULL);
+ xpthread_sigmask(SIG_SETMASK, oldsigs, NULL);
}
long long int
}
/* Returns the monotonic time at which the "time" module was initialized, in
- * milliseconds(). */
+ * milliseconds. */
long long int
time_boot_msec(void)
{
xgettimeofday(struct timeval *tv)
{
if (gettimeofday(tv, NULL) == -1) {
- VLOG_FATAL("gettimeofday failed (%s)", strerror(errno));
+ VLOG_FATAL("gettimeofday failed (%s)", ovs_strerror(errno));
+ }
+}
+
+void
+xclock_gettime(clock_t id, struct timespec *ts)
+{
+ if (clock_gettime(id, ts) == -1) {
+ /* It seems like a bad idea to try to use vlog here because it is
+ * likely to try to check the current time. */
+ ovs_abort(errno, "xclock_gettime() failed");
}
}
{
long long int interval = time_msec() - last_wakeup;
- if (interval >= 1000 && !warp_offset.tv_sec && !warp_offset.tv_nsec) {
+ if (interval >= 1000
+ && !monotonic_clock.warp.tv_sec
+ && !monotonic_clock.warp.tv_nsec) {
const struct rusage *last_rusage = get_recent_rusage();
struct rusage rusage;
unsigned long long int cpu; /* Total user+system CPU usage when sampled. */
};
-static struct rusage recent_rusage;
-static struct cpu_usage older = { LLONG_MIN, 0 };
-static struct cpu_usage newer = { LLONG_MIN, 0 };
-static int cpu_usage = -1;
+struct cpu_tracker {
+ struct cpu_usage older;
+ struct cpu_usage newer;
+ int cpu_usage;
+
+ struct rusage recent_rusage;
+};
+DEFINE_PER_THREAD_MALLOCED_DATA(struct cpu_tracker *, cpu_tracker_var);
+
+static struct cpu_tracker *
+get_cpu_tracker(void)
+{
+ struct cpu_tracker *t = cpu_tracker_var_get();
+ if (!t) {
+ t = xzalloc(sizeof *t);
+ t->older.when = LLONG_MIN;
+ t->newer.when = LLONG_MIN;
+ cpu_tracker_var_set_unsafe(t);
+ }
+ return t;
+}
static struct rusage *
get_recent_rusage(void)
{
- return &recent_rusage;
+ return &get_cpu_tracker()->recent_rusage;
+}
+
+static int
+getrusage_thread(struct rusage *rusage OVS_UNUSED)
+{
+#ifdef RUSAGE_THREAD
+ return getrusage(RUSAGE_THREAD, rusage);
+#else
+ errno = EINVAL;
+ return -1;
+#endif
}
static void
refresh_rusage(void)
{
- long long int now;
+ struct cpu_tracker *t = get_cpu_tracker();
+ struct rusage *recent_rusage = &t->recent_rusage;
- now = time_msec();
- getrusage(RUSAGE_SELF, &recent_rusage);
-
- if (now >= newer.when + 3 * 1000) {
- older = newer;
- newer.when = now;
- newer.cpu = (timeval_to_msec(&recent_rusage.ru_utime) +
- timeval_to_msec(&recent_rusage.ru_stime));
-
- if (older.when != LLONG_MIN && newer.cpu > older.cpu) {
- unsigned int dividend = newer.cpu - older.cpu;
- unsigned int divisor = (newer.when - older.when) / 100;
- cpu_usage = divisor > 0 ? dividend / divisor : -1;
- } else {
- cpu_usage = -1;
+ if (!getrusage_thread(recent_rusage)) {
+ long long int now = time_msec();
+ if (now >= t->newer.when + 3 * 1000) {
+ t->older = t->newer;
+ t->newer.when = now;
+ t->newer.cpu = (timeval_to_msec(&recent_rusage->ru_utime) +
+ timeval_to_msec(&recent_rusage->ru_stime));
+
+ if (t->older.when != LLONG_MIN && t->newer.cpu > t->older.cpu) {
+ unsigned int dividend = t->newer.cpu - t->older.cpu;
+ unsigned int divisor = (t->newer.when - t->older.when) / 100;
+ t->cpu_usage = divisor > 0 ? dividend / divisor : -1;
+ } else {
+ t->cpu_usage = -1;
+ }
}
}
}
int
get_cpu_usage(void)
{
- return cpu_usage;
-}
-
-static uint32_t
-hash_trace(struct trace *trace)
-{
- return hash_bytes(trace->backtrace,
- trace->n_frames * sizeof *trace->backtrace, 0);
-}
-
-static struct trace *
-trace_map_lookup(struct hmap *trace_map, struct trace *key)
-{
- struct trace *value;
-
- HMAP_FOR_EACH_WITH_HASH (value, node, hash_trace(key), trace_map) {
- if (key->n_frames == value->n_frames
- && !memcmp(key->backtrace, value->backtrace,
- key->n_frames * sizeof *key->backtrace)) {
- return value;
- }
- }
- return NULL;
-}
-
-/* Appends a string to 'ds' representing backtraces recorded at regular
- * intervals in the recent past. This information can be used to get a sense
- * of what the process has been spending the majority of time doing. Will
- * ommit any backtraces which have not occurred at least 'min_count' times. */
-void
-format_backtraces(struct ds *ds, size_t min_count)
-{
- time_init();
-
- if (HAVE_EXECINFO_H && CACHE_TIME) {
- struct hmap trace_map = HMAP_INITIALIZER(&trace_map);
- struct trace *trace, *next;
- sigset_t oldsigs;
- size_t i;
-
- block_sigalrm(&oldsigs);
-
- for (i = 0; i < MAX_TRACES; i++) {
- struct trace *trace = &traces[i];
- struct trace *map_trace;
-
- if (!trace->n_frames) {
- continue;
- }
-
- map_trace = trace_map_lookup(&trace_map, trace);
- if (map_trace) {
- map_trace->count++;
- } else {
- hmap_insert(&trace_map, &trace->node, hash_trace(trace));
- trace->count = 1;
- }
- }
-
- HMAP_FOR_EACH_SAFE (trace, next, node, &trace_map) {
- char **frame_strs;
- size_t j;
-
- hmap_remove(&trace_map, &trace->node);
-
- if (trace->count < min_count) {
- continue;
- }
-
- frame_strs = backtrace_symbols(trace->backtrace, trace->n_frames);
-
- ds_put_format(ds, "Count %zu\n", trace->count);
- for (j = 0; j < trace->n_frames; j++) {
- ds_put_format(ds, "%s\n", frame_strs[j]);
- }
- ds_put_cstr(ds, "\n");
-
- free(frame_strs);
- }
- hmap_destroy(&trace_map);
-
- ds_chomp(ds, '\n');
- unblock_sigalrm(&oldsigs);
- }
+ return get_cpu_tracker()->cpu_usage;
}
\f
/* Unixctl interface. */
int argc OVS_UNUSED, const char *argv[] OVS_UNUSED,
void *aux OVS_UNUSED)
{
- time_stopped = true;
+ ovs_rwlock_wrlock(&monotonic_clock.rwlock);
+ monotonic_clock.stopped = true;
+ ovs_rwlock_unlock(&monotonic_clock.rwlock);
+
unixctl_command_reply(conn, NULL);
}
ts.tv_sec = msecs / 1000;
ts.tv_nsec = (msecs % 1000) * 1000 * 1000;
- timespec_add(&warp_offset, &warp_offset, &ts);
- timespec_add(&monotonic_time, &monotonic_time, &ts);
- unixctl_command_reply(conn, "warped");
-}
-static void
-backtrace_cb(struct unixctl_conn *conn,
- int argc OVS_UNUSED, const char *argv[] OVS_UNUSED,
- void *aux OVS_UNUSED)
-{
- struct ds ds = DS_EMPTY_INITIALIZER;
+ ovs_rwlock_wrlock(&monotonic_clock.rwlock);
+ timespec_add(&monotonic_clock.warp, &monotonic_clock.warp, &ts);
+ ovs_rwlock_unlock(&monotonic_clock.rwlock);
- ovs_assert(HAVE_EXECINFO_H && CACHE_TIME);
- format_backtraces(&ds, 0);
- unixctl_command_reply(conn, ds_cstr(&ds));
- ds_destroy(&ds);
+ unixctl_command_reply(conn, "warped");
}
void
git://git.onelab.eu / sliver-openvswitch.git / blobdiff