#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 <kern/spl.h>
#include <kern/thread.h>
#include <kern/processor.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;
thread_lock(thread);
if (!(thread->sched_mode & TH_MODE_TIMESHARE)) {
uint64_t new_computation;
new_computation = processor->quantum_end;
new_computation -= thread->computation_epoch;
if (new_computation + thread->computation_metered >
max_unsafe_computation) {
if (thread->sched_mode & TH_MODE_REALTIME) {
thread->priority = DEPRESSPRI;
thread->safe_mode |= TH_MODE_REALTIME;
thread->sched_mode &= ~TH_MODE_REALTIME;
}
sched_share_incr();
thread->safe_release = sched_tick + sched_safe_duration;
thread->sched_mode |= (TH_MODE_FAILSAFE|TH_MODE_TIMESHARE);
thread->sched_mode &= ~TH_MODE_PREEMPT;
}
}
if (thread->sched_stamp != sched_tick)
update_priority(thread);
else
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_mode & TH_MODE_PROMOTED) &&
!(thread->sched_mode & TH_MODE_ISDEPRESSED) )
compute_my_priority(thread);
}
processor->current_pri = thread->sched_pri;
if (first_timeslice(processor))
processor->timeslice--;
thread_quantum_init(thread);
processor->quantum_end += thread->current_quantum;
timer_call_enter1(&processor->quantum_timer,
thread, processor->quantum_end);
if ((preempt = csw_check(thread, processor)) != AST_NONE)
ast_on(preempt);
else {
processor_set_t pset = processor->processor_set;
pset_lock(pset);
pset_hint_low(pset, processor);
pset_hint_high(pset, processor);
pset_unlock(pset);
}
thread_unlock(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
void
set_priority(
register thread_t thread,
register int priority)
{
thread->priority = priority;
compute_priority(thread, FALSE);
}
void
compute_priority(
register thread_t thread,
boolean_t override_depress)
{
register int priority;
if ( !(thread->sched_mode & TH_MODE_PROMOTED) &&
(!(thread->sched_mode & TH_MODE_ISDEPRESSED) ||
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;
}
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;
thread->pri_shift = sched_pri_shift;
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_mode & TH_MODE_FAILSAFE) &&
thread->sched_stamp >= thread->safe_release ) {
if (!(thread->safe_mode & TH_MODE_TIMESHARE)) {
if (thread->safe_mode & TH_MODE_REALTIME) {
thread->priority = BASEPRI_RTQUEUES;
thread->sched_mode |= TH_MODE_REALTIME;
}
thread->sched_mode &= ~TH_MODE_TIMESHARE;
if ((thread->state & (TH_RUN|TH_IDLE)) == TH_RUN)
sched_share_decr();
if (!(thread->sched_mode & TH_MODE_ISDEPRESSED))
set_sched_pri(thread, thread->priority);
}
thread->safe_mode = 0;
thread->sched_mode &= ~TH_MODE_FAILSAFE;
}
if ( (thread->sched_mode & TH_MODE_TIMESHARE) &&
!(thread->sched_mode & TH_MODE_PROMOTED) &&
!(thread->sched_mode & TH_MODE_ISDEPRESSED) ) {
register int new_pri;
do_priority_computation(thread, new_pri);
if (new_pri != thread->sched_pri) {
boolean_t removed = run_queue_remove(thread);
thread->sched_pri = new_pri;
if (removed)
thread_setrun(thread, SCHED_TAILQ);
}
}
}