irqreturn_t timer_interrupt(int irq, void *dummy)
{
/* last time the cmos clock got updated */
static long last_rtc_update;
write_raw_seqlock(&xtime_lock);
do_timer(1);
/*
* If we have an externally synchronized Linux clock, then update
* CMOS clock accordingly every ~11 minutes. Set_rtc_mmss() has to be
* called as close as possible to 500 ms before the new second starts.
*/
if (ntp_synced() &&
xtime.tv_sec > last_rtc_update + 660 &&
(xtime.tv_nsec / NSEC_PER_USEC) >=
500000 - ((unsigned)TICK_SIZE) / 2
&& (xtime.tv_nsec / NSEC_PER_USEC) <=
500000 + ((unsigned)TICK_SIZE) / 2) {
if (set_rtc_mmss(xtime.tv_sec) == 0)
last_rtc_update = xtime.tv_sec;
else
/* Do it again in 60s. */
last_rtc_update = xtime.tv_sec - 600;
}
write_raw_sequnlock(&xtime_lock);
#ifdef CONFIG_IPIPE
update_root_process_times(get_irq_regs());
#else
update_process_times(user_mode(get_irq_regs()));
#endif
profile_tick(CPU_PROFILING);
return IRQ_HANDLED;
}
static unsigned long
consider_steal_time(unsigned long new_itm)
{
unsigned long stolen, blocked;
unsigned long delta_itm = 0, stolentick = 0;
int cpu = smp_processor_id();
struct vcpu_runstate_info runstate;
struct task_struct *p = current;
get_runstate_snapshot(&runstate);
/*
* Check for vcpu migration effect
* In this case, itc value is reversed.
* This causes huge stolen value.
* This function just checks and reject this effect.
*/
if (!time_after_eq(runstate.time[RUNSTATE_blocked],
per_cpu(xen_blocked_time, cpu)))
blocked = 0;
if (!time_after_eq(runstate.time[RUNSTATE_runnable] +
runstate.time[RUNSTATE_offline],
per_cpu(xen_stolen_time, cpu)))
stolen = 0;
if (!time_after(delta_itm + new_itm, ia64_get_itc()))
stolentick = ia64_get_itc() - new_itm;
do_div(stolentick, NS_PER_TICK);
stolentick++;
do_div(stolen, NS_PER_TICK);
if (stolen > stolentick)
stolen = stolentick;
stolentick -= stolen;
do_div(blocked, NS_PER_TICK);
if (blocked > stolentick)
blocked = stolentick;
if (stolen > 0 || blocked > 0) {
account_steal_ticks(stolen);
account_idle_ticks(blocked);
run_local_timers();
rcu_check_callbacks(cpu, user_mode(get_irq_regs()));
scheduler_tick();
run_posix_cpu_timers(p);
delta_itm += local_cpu_data->itm_delta * (stolen + blocked);
if (cpu == time_keeper_id) {
write_raw_seqlock(&xtime_lock);
do_timer(stolen + blocked);
local_cpu_data->itm_next = delta_itm + new_itm;
write_raw_sequnlock(&xtime_lock);
} else {
local_cpu_data->itm_next = delta_itm + new_itm;
}
per_cpu(xen_stolen_time, cpu) += NS_PER_TICK * stolen;
per_cpu(xen_blocked_time, cpu) += NS_PER_TICK * blocked;
}
return delta_itm;
}
