void resched_cpu(int cpu)
{
struct rq *rq = cpu_rq(cpu);
unsigned long flags;
if (!raw_spin_trylock_irqsave(&rq->lock, flags))
return;
resched_task(cpu_curr(cpu));
raw_spin_unlock_irqrestore(&rq->lock, flags);
}
static void fastcall reschedule_idle(struct task_struct * p)
{
#ifdef CONFIG_SMP
#if 0
// not yet?
int this_cpu = smp_processor_id();
struct task_struct *tsk, *target_tsk;
int cpu, best_cpu, i, max_prio;
cycles_t oldest_idle;
/*
* shortcut if the woken up task's last CPU is
* idle now.
*/
best_cpu = p->pcb$l_cpu_id;
if (can_schedule(p, best_cpu)) {
tsk = idle_task(best_cpu);
if (cpu_curr(best_cpu) == tsk) {
int need_resched;
send_now_idle:
/*
* If need_resched == -1 then we can skip sending
* the IPI altogether, tsk->need_resched is
* actively watched by the idle thread.
*/
need_resched = tsk->need_resched;
tsk->need_resched = 1;
if ((best_cpu != this_cpu) && !need_resched)
smp_send_reschedule(best_cpu);
return;
}
}
/*
* We know that the preferred CPU has a cache-affine current
* process, lets try to find a new idle CPU for the woken-up
* process. Select the least recently active idle CPU. (that
* one will have the least active cache context.) Also find
* the executing process which has the least priority.
*/
oldest_idle = (cycles_t) -1;
target_tsk = NULL;
max_prio = 0;
for (i = 0; i < smp_num_cpus; i++) {
cpu = cpu_logical_map(i);
if (!can_schedule(p, cpu))
continue;
tsk = cpu_curr(cpu);
/*
* We use the first available idle CPU. This creates
* a priority list between idle CPUs, but this is not
* a problem.
*/
if (tsk == idle_task(cpu)) {
if (last_schedule(cpu) < oldest_idle) {
oldest_idle = last_schedule(cpu);
target_tsk = tsk;
}
} else {
if (oldest_idle == -1ULL) {
int prio = preemption_goodness(tsk, p, cpu);
if (prio > max_prio) {
max_prio = prio;
target_tsk = tsk;
}
}
}
}
tsk = target_tsk;
if (tsk) {
if (oldest_idle != -1ULL) {
best_cpu = tsk->pcb$l_cpu_id;
goto send_now_idle;
}
tsk->need_resched = 1;
if (tsk->pcb$l_cpu_id != this_cpu)
smp_send_reschedule(tsk->pcb$l_cpu_id);
}
return;
#endif
#else /* UP */
int this_cpu = smp_processor_id();
struct task_struct *tsk;
tsk = ctl$gl_pcb;
if (p->pcb$b_pri >= tsk->pcb$b_pri) /* previous was meaningless */
tsk->need_resched = 1;
#endif
}
struct task_struct *get_rq_task(int cpu)
{
return cpu_curr(cpu);
}
