#include <mach/boolean.h>
#include <mach/kern_return.h>
#include <mach/machine.h>
#include <kern/host.h>
#include <kern/mach_param.h>
#include <kern/sched.h>
#include <sys/kdebug.h>
#include <kern/spl.h>
#include <kern/thread.h>
#include <kern/processor.h>
#include <kern/ledger.h>
#include <machine/machparam.h>
void
thread_quantum_expire(
timer_call_param_t p0,
timer_call_param_t p1)
{
processor_t processor = p0;
thread_t thread = p1;
ast_t preempt;
uint64_t ctime;
SCHED_STATS_QUANTUM_TIMER_EXPIRATION(processor);
ledger_credit(thread->t_ledger, task_ledgers.cpu_time, thread->current_quantum);
ledger_credit(thread->t_threadledger, thread_ledgers.cpu_time, thread->current_quantum);
thread_lock(thread);
thread->last_run_time = processor->quantum_end;
if ((thread->sched_mode == TH_MODE_REALTIME || thread->sched_mode == TH_MODE_FIXED) &&
!(thread->sched_flags & TH_SFLAG_PROMOTED_MASK) &&
!(thread->options & TH_OPT_SYSTEM_CRITICAL)) {
uint64_t new_computation;
new_computation = processor->quantum_end - thread->computation_epoch;
new_computation += thread->computation_metered;
if (new_computation > max_unsafe_computation) {
KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_FAILSAFE)|DBG_FUNC_NONE,
(uintptr_t)thread->sched_pri, (uintptr_t)thread->sched_mode, 0, 0, 0);
if (thread->sched_mode == TH_MODE_REALTIME) {
thread->priority = DEPRESSPRI;
}
thread->saved_mode = thread->sched_mode;
if (SCHED(supports_timeshare_mode)) {
sched_share_incr();
thread->sched_mode = TH_MODE_TIMESHARE;
} else {
thread->sched_mode = TH_MODE_FIXED;
}
thread->safe_release = processor->quantum_end + sched_safe_duration;
thread->sched_flags |= TH_SFLAG_FAILSAFE;
}
}
if (SCHED(can_update_priority)(thread))
SCHED(update_priority)(thread);
else
SCHED(lightweight_update_priority)(thread);
SCHED(quantum_expire)(thread);
processor->current_pri = thread->sched_pri;
processor->current_thmode = thread->sched_mode;
if (first_timeslice(processor))
processor->timeslice--;
thread_quantum_init(thread);
thread->last_quantum_refill_time = processor->quantum_end;
thread->precise_user_kernel_time = use_precise_user_kernel_time(thread);
if (!thread->precise_user_kernel_time) {
timer_switch(PROCESSOR_DATA(processor, current_state),
processor->quantum_end,
PROCESSOR_DATA(processor, current_state));
timer_switch(PROCESSOR_DATA(processor, thread_timer),
processor->quantum_end,
PROCESSOR_DATA(processor, thread_timer));
}
ctime = mach_absolute_time();
processor->quantum_end = ctime + thread->current_quantum;
timer_call_enter1(&processor->quantum_timer, thread,
processor->quantum_end, TIMER_CALL_SYS_CRITICAL);
if ((preempt = csw_check(processor)) != AST_NONE)
ast_on(preempt);
else {
processor_set_t pset = processor->processor_set;
pset_lock(pset);
pset_pri_hint(pset, processor, processor->current_pri);
pset_count_hint(pset, processor, SCHED(processor_runq_count)(processor));
pset_unlock(pset);
}
thread_unlock(thread);
#if defined(CONFIG_SCHED_TRADITIONAL)
sched_traditional_consider_maintenance(ctime);
#endif
}
#if defined(CONFIG_SCHED_TRADITIONAL)
void
sched_traditional_quantum_expire(thread_t thread __unused)
{
}
void
lightweight_update_priority(thread_t thread)
{
if (thread->sched_mode == TH_MODE_TIMESHARE) {
register uint32_t delta;
thread_timer_delta(thread, delta);
if (thread->pri_shift < INT8_MAX)
thread->sched_usage += delta;
thread->cpu_delta += delta;
if ( !(thread->sched_flags & TH_SFLAG_PROMOTED_MASK) &&
!(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK) )
compute_my_priority(thread);
}
}
struct shift_data {
int shift1;
int shift2;
};
#define SCHED_DECAY_TICKS 32
static struct shift_data sched_decay_shifts[SCHED_DECAY_TICKS] = {
{1,1},{1,3},{1,-3},{2,-7},{3,5},{3,-5},{4,-8},{5,7},
{5,-7},{6,-10},{7,10},{7,-9},{8,-11},{9,12},{9,-11},{10,-13},
{11,14},{11,-13},{12,-15},{13,17},{13,-15},{14,-17},{15,19},{16,18},
{16,-19},{17,22},{18,20},{18,-20},{19,26},{20,22},{20,-22},{21,-27}
};
#define do_priority_computation(thread, pri) \
MACRO_BEGIN \
(pri) = (thread)->priority \
- ((thread)->sched_usage >> (thread)->pri_shift); \
if ((pri) < MINPRI_USER) \
(pri) = MINPRI_USER; \
else \
if ((pri) > MAXPRI_KERNEL) \
(pri) = MAXPRI_KERNEL; \
MACRO_END
#endif
void
set_priority(
register thread_t thread,
register int priority)
{
thread->priority = priority;
SCHED(compute_priority)(thread, FALSE);
}
#if defined(CONFIG_SCHED_TRADITIONAL)
void
compute_priority(
register thread_t thread,
boolean_t override_depress)
{
register int priority;
if ( !(thread->sched_flags & TH_SFLAG_PROMOTED_MASK) &&
(!(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK) ||
override_depress ) ) {
if (thread->sched_mode == TH_MODE_TIMESHARE)
do_priority_computation(thread, priority);
else
priority = thread->priority;
set_sched_pri(thread, priority);
}
}
void
compute_my_priority(
register thread_t thread)
{
register int priority;
do_priority_computation(thread, priority);
assert(thread->runq == PROCESSOR_NULL);
thread->sched_pri = priority;
}
boolean_t
can_update_priority(
thread_t thread)
{
if (sched_tick == thread->sched_stamp)
return (FALSE);
else
return (TRUE);
}
void
update_priority(
register thread_t thread)
{
register unsigned ticks;
register uint32_t delta;
ticks = sched_tick - thread->sched_stamp;
assert(ticks != 0);
thread->sched_stamp += ticks;
if (sched_use_combined_fgbg_decay)
thread->pri_shift = sched_combined_fgbg_pri_shift;
else if (thread->max_priority <= MAXPRI_THROTTLE)
thread->pri_shift = sched_background_pri_shift;
else
thread->pri_shift = sched_pri_shift;
if (sched_decay_usage_age_factor > 1)
ticks *= sched_decay_usage_age_factor;
thread_timer_delta(thread, delta);
if (ticks < SCHED_DECAY_TICKS) {
register struct shift_data *shiftp;
if (thread->pri_shift < INT8_MAX)
thread->sched_usage += delta;
thread->cpu_usage += delta + thread->cpu_delta;
thread->cpu_delta = 0;
shiftp = &sched_decay_shifts[ticks];
if (shiftp->shift2 > 0) {
thread->cpu_usage =
(thread->cpu_usage >> shiftp->shift1) +
(thread->cpu_usage >> shiftp->shift2);
thread->sched_usage =
(thread->sched_usage >> shiftp->shift1) +
(thread->sched_usage >> shiftp->shift2);
}
else {
thread->cpu_usage =
(thread->cpu_usage >> shiftp->shift1) -
(thread->cpu_usage >> -(shiftp->shift2));
thread->sched_usage =
(thread->sched_usage >> shiftp->shift1) -
(thread->sched_usage >> -(shiftp->shift2));
}
}
else {
thread->cpu_usage = thread->cpu_delta = 0;
thread->sched_usage = 0;
}
if ( (thread->sched_flags & TH_SFLAG_FAILSAFE) &&
mach_absolute_time() >= thread->safe_release ) {
if (thread->saved_mode != TH_MODE_TIMESHARE) {
if (thread->saved_mode == TH_MODE_REALTIME) {
thread->priority = BASEPRI_RTQUEUES;
}
thread->sched_mode = thread->saved_mode;
thread->saved_mode = TH_MODE_NONE;
if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN)
sched_share_decr();
if (!(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK))
set_sched_pri(thread, thread->priority);
}
thread->sched_flags &= ~TH_SFLAG_FAILSAFE;
}
if ( (thread->sched_mode == TH_MODE_TIMESHARE) &&
!(thread->sched_flags & TH_SFLAG_PROMOTED_MASK) &&
!(thread->sched_flags & TH_SFLAG_DEPRESSED_MASK) ) {
register int new_pri;
do_priority_computation(thread, new_pri);
if (new_pri != thread->sched_pri) {
boolean_t removed = thread_run_queue_remove(thread);
#if 0
if (sched_use_combined_fgbg_decay && ((thread)->task->max_priority > MAXPRI_THROTTLE) && (new_pri == MAXPRI_THROTTLE)) {
int alt_pri = thread->priority - (thread->sched_usage >> sched_pri_shift);
if ((alt_pri > new_pri) && (sched_background_count > 0)) {
printf("thread %p would have decayed to only %d instead of %d\n", thread, alt_pri, new_pri);
}
}
#endif
KERNEL_DEBUG_CONSTANT(MACHDBG_CODE(DBG_MACH_SCHED, MACH_SCHED_DECAY_PRIORITY)|DBG_FUNC_NONE,
(uintptr_t)thread_tid(thread),
thread->priority,
thread->sched_pri,
new_pri,
0);
thread->sched_pri = new_pri;
if (removed)
thread_setrun(thread, SCHED_TAILQ);
}
}
return;
}
#endif