static struct callout_cpu *
callout_lock(struct callout *c)
{
struct callout_cpu *cc;
int cpu;
for (;;) {
cpu = c->c_cpu;
cc = CC_CPU(cpu);
CC_LOCK(cc);
if (cpu == c->c_cpu)
break;
CC_UNLOCK(cc);
}
return (cc);
}
/*
* Software (low priority) clock interrupt.
* Run periodic events from timeout queue.
*/
void
softclock(void *arg)
{
struct callout_cpu *cc;
struct callout *c;
struct callout_tailq *bucket;
int curticks;
int steps; /* #steps since we last allowed interrupts */
int depth;
int mpcalls;
int lockcalls;
int gcalls;
#ifndef MAX_SOFTCLOCK_STEPS
#define MAX_SOFTCLOCK_STEPS 100 /* Maximum allowed value of steps. */
#endif /* MAX_SOFTCLOCK_STEPS */
mpcalls = 0;
lockcalls = 0;
gcalls = 0;
depth = 0;
steps = 0;
cc = (struct callout_cpu *)arg;
CC_LOCK(cc);
while (cc->cc_softticks - 1 != cc->cc_ticks) {
/*
* cc_softticks may be modified by hard clock, so cache
* it while we work on a given bucket.
*/
curticks = cc->cc_softticks;
cc->cc_softticks++;
bucket = &cc->cc_callwheel[curticks & callwheelmask];
c = BSD_TAILQ_FIRST(bucket);
while (c != NULL) {
depth++;
if (c->c_time != curticks) {
c = BSD_TAILQ_NEXT(c, c_links.tqe);
++steps;
if (steps >= MAX_SOFTCLOCK_STEPS) {
cc->cc_next = c;
/* Give interrupts a chance. */
CC_UNLOCK(cc);
; /* nothing */
CC_LOCK(cc);
c = cc->cc_next;
steps = 0;
}
} else {
cc->cc_next = BSD_TAILQ_NEXT(c, c_links.tqe);
BSD_TAILQ_REMOVE(bucket, c, c_links.tqe);
softclock_call_cc(c, cc, &mpcalls,
&lockcalls, &gcalls);
steps = 0;
c = cc->cc_next;
}
}
}
avg_depth += (depth * 1000 - avg_depth) >> 8;
avg_mpcalls += (mpcalls * 1000 - avg_mpcalls) >> 8;
avg_lockcalls += (lockcalls * 1000 - avg_lockcalls) >> 8;
avg_gcalls += (gcalls * 1000 - avg_gcalls) >> 8;
cc->cc_next = NULL;
CC_UNLOCK(cc);
}
static void
softclock_call_cc(struct callout *c, struct callout_cpu *cc, int *mpcalls,
int *lockcalls, int *gcalls)
{
void (*c_func)(void *);
void *c_arg;
int c_flags;
#ifdef DIAGNOSTIC
struct bintime bt1, bt2;
struct timespec ts2;
static uint64_t maxdt = 36893488147419102LL; /* 2 msec */
static timeout_t *lastfunc;
#endif
KASSERT((c->c_flags & (CALLOUT_PENDING | CALLOUT_ACTIVE)) ==
(CALLOUT_PENDING | CALLOUT_ACTIVE),
("softclock_call_cc: pend|act %p %x", c, c->c_flags));
c_func = c->c_func;
c_arg = c->c_arg;
c_flags = c->c_flags;
if (c->c_flags & CALLOUT_LOCAL_ALLOC)
c->c_flags = CALLOUT_LOCAL_ALLOC;
else
c->c_flags &= ~CALLOUT_PENDING;
cc->cc_curr = c;
cc->cc_cancel = 0;
CC_UNLOCK(cc);
{
(*mpcalls)++;
CTR3(KTR_CALLOUT, "callout mpsafe %p func %p arg %p",
c, c_func, c_arg);
}
#ifdef DIAGNOSTIC
binuptime(&bt1);
#endif
c_func(c_arg);
#ifdef DIAGNOSTIC
binuptime(&bt2);
bintime_sub(&bt2, &bt1);
if (bt2.frac > maxdt) {
if (lastfunc != c_func || bt2.frac > maxdt * 2) {
bintime2timespec(&bt2, &ts2);
printf(
"Expensive timeout(9) function: %p(%p) %jd.%09ld s\n",
c_func, c_arg, (intmax_t)ts2.tv_sec, ts2.tv_nsec);
}
maxdt = bt2.frac;
lastfunc = c_func;
}
#endif
CTR1(KTR_CALLOUT, "callout %p finished", c);
CC_LOCK(cc);
KASSERT(cc->cc_curr == c, ("mishandled cc_curr"));
cc->cc_curr = NULL;
/*
* If the current callout is locally allocated (from
* timeout(9)) then put it on the freelist.
*
* Note: we need to check the cached copy of c_flags because
* if it was not local, then it's not safe to deref the
* callout pointer.
*/
KASSERT((c_flags & CALLOUT_LOCAL_ALLOC) == 0 ||
c->c_flags == CALLOUT_LOCAL_ALLOC,
("corrupted callout"));
if (c_flags & CALLOUT_LOCAL_ALLOC)
callout_cc_del(c, cc);
}
/*
* Software (low priority) clock interrupt.
* Run periodic events from timeout queue.
*/
void
softclock(void *arg)
{
struct callout_cpu *cc;
struct callout *c;
struct callout_tailq *bucket;
int curticks;
int steps; /* #steps since we last allowed interrupts */
int depth;
int mpcalls;
int lockcalls;
int gcalls;
#ifdef DIAGNOSTIC
struct bintime bt1, bt2;
struct timespec ts2;
static uint64_t maxdt = 36893488147419102LL; /* 2 msec */
static timeout_t *lastfunc;
#endif
#ifndef MAX_SOFTCLOCK_STEPS
#define MAX_SOFTCLOCK_STEPS 100 /* Maximum allowed value of steps. */
#endif /* MAX_SOFTCLOCK_STEPS */
mpcalls = 0;
lockcalls = 0;
gcalls = 0;
depth = 0;
steps = 0;
cc = (struct callout_cpu *)arg;
CC_LOCK(cc);
while (cc->cc_softticks != ticks) {
/*
* cc_softticks may be modified by hard clock, so cache
* it while we work on a given bucket.
*/
curticks = cc->cc_softticks;
cc->cc_softticks++;
bucket = &cc->cc_callwheel[curticks & callwheelmask];
c = TAILQ_FIRST(bucket);
while (c) {
depth++;
if (c->c_time != curticks) {
c = TAILQ_NEXT(c, c_links.tqe);
++steps;
if (steps >= MAX_SOFTCLOCK_STEPS) {
cc->cc_next = c;
/* Give interrupts a chance. */
CC_UNLOCK(cc);
; /* nothing */
CC_LOCK(cc);
c = cc->cc_next;
steps = 0;
}
} else {
void (*c_func)(void *);
void *c_arg;
struct lock_class *class;
struct lock_object *c_lock;
int c_flags, sharedlock;
cc->cc_next = TAILQ_NEXT(c, c_links.tqe);
TAILQ_REMOVE(bucket, c, c_links.tqe);
class = (c->c_lock != NULL) ?
LOCK_CLASS(c->c_lock) : NULL;
sharedlock = (c->c_flags & CALLOUT_SHAREDLOCK) ?
0 : 1;
c_lock = c->c_lock;
c_func = c->c_func;
c_arg = c->c_arg;
c_flags = c->c_flags;
if (c->c_flags & CALLOUT_LOCAL_ALLOC) {
c->c_flags = CALLOUT_LOCAL_ALLOC;
} else {
c->c_flags =
(c->c_flags & ~CALLOUT_PENDING);
}
cc->cc_curr = c;
cc->cc_cancel = 0;
CC_UNLOCK(cc);
if (c_lock != NULL) {
class->lc_lock(c_lock, sharedlock);
/*
* The callout may have been cancelled
* while we switched locks.
*/
if (cc->cc_cancel) {
class->lc_unlock(c_lock);
goto skip;
}
/* The callout cannot be stopped now. */
cc->cc_cancel = 1;
if (c_lock == &Giant.lock_object) {
gcalls++;
CTR3(KTR_CALLOUT,
"callout %p func %p arg %p",
c, c_func, c_arg);
} else {
lockcalls++;
CTR3(KTR_CALLOUT, "callout lock"
" %p func %p arg %p",
c, c_func, c_arg);
}
} else {
mpcalls++;
CTR3(KTR_CALLOUT,
"callout mpsafe %p func %p arg %p",
c, c_func, c_arg);
}
#ifdef DIAGNOSTIC
binuptime(&bt1);
#endif
THREAD_NO_SLEEPING();
SDT_PROBE(callout_execute, kernel, ,
callout_start, c, 0, 0, 0, 0);
c_func(c_arg);
SDT_PROBE(callout_execute, kernel, ,
callout_end, c, 0, 0, 0, 0);
THREAD_SLEEPING_OK();
#ifdef DIAGNOSTIC
binuptime(&bt2);
bintime_sub(&bt2, &bt1);
if (bt2.frac > maxdt) {
if (lastfunc != c_func ||
bt2.frac > maxdt * 2) {
bintime2timespec(&bt2, &ts2);
printf(
"Expensive timeout(9) function: %p(%p) %jd.%09ld s\n",
c_func, c_arg,
(intmax_t)ts2.tv_sec,
ts2.tv_nsec);
}
maxdt = bt2.frac;
lastfunc = c_func;
}
#endif
CTR1(KTR_CALLOUT, "callout %p finished", c);
if ((c_flags & CALLOUT_RETURNUNLOCKED) == 0)
class->lc_unlock(c_lock);
skip:
CC_LOCK(cc);
/*
* If the current callout is locally
* allocated (from timeout(9))
* then put it on the freelist.
*
* Note: we need to check the cached
* copy of c_flags because if it was not
* local, then it's not safe to deref the
* callout pointer.
*/
if (c_flags & CALLOUT_LOCAL_ALLOC) {
KASSERT(c->c_flags ==
CALLOUT_LOCAL_ALLOC,
("corrupted callout"));
c->c_func = NULL;
SLIST_INSERT_HEAD(&cc->cc_callfree, c,
c_links.sle);
}
cc->cc_curr = NULL;
if (cc->cc_waiting) {
/*
* There is someone waiting
* for the callout to complete.
*/
cc->cc_waiting = 0;
CC_UNLOCK(cc);
wakeup(&cc->cc_waiting);
CC_LOCK(cc);
}
steps = 0;
c = cc->cc_next;
}
}
}
