/*
* Update process times based on virtual cpu times stored by entry.S
* to the lowcore fields user_timer, system_timer & steal_clock.
*/
void account_process_tick(struct task_struct *tsk, int user_tick)
{
cputime_t cputime;
__u64 timer, clock;
int rcu_user_flag;
timer = S390_lowcore.last_update_timer;
clock = S390_lowcore.last_update_clock;
asm volatile (" STPT %0\n" /* Store current cpu timer value */
" STCK %1" /* Store current tod clock value */
: "=m" (S390_lowcore.last_update_timer),
"=m" (S390_lowcore.last_update_clock) );
S390_lowcore.system_timer += timer - S390_lowcore.last_update_timer;
S390_lowcore.steal_clock += S390_lowcore.last_update_clock - clock;
cputime = S390_lowcore.user_timer >> 12;
rcu_user_flag = cputime != 0;
S390_lowcore.user_timer -= cputime << 12;
S390_lowcore.steal_clock -= cputime << 12;
account_user_time(tsk, cputime);
cputime = S390_lowcore.system_timer >> 12;
S390_lowcore.system_timer -= cputime << 12;
S390_lowcore.steal_clock -= cputime << 12;
account_system_time(tsk, HARDIRQ_OFFSET, cputime);
cputime = S390_lowcore.steal_clock;
if ((__s64) cputime > 0) {
cputime >>= 12;
S390_lowcore.steal_clock -= cputime << 12;
account_steal_time(tsk, cputime);
}
/*
* Account a single tick of cpu time.
* @p: the process that the cpu time gets accounted to
* @user_tick: indicates if the tick is a user or a system tick
*/
void account_process_tick(struct task_struct *p, int user_tick)
{
cputime_t one_jiffy_scaled = cputime_to_scaled(cputime_one_jiffy);
struct rq *rq = this_rq();
if (sched_clock_irqtime) {
irqtime_account_process_tick(p, user_tick, rq);
return;
}
if (steal_account_process_tick())
return;
if (user_tick)
account_user_time(p, cputime_one_jiffy, one_jiffy_scaled);
else if ((p != rq->idle) || (irq_count() != HARDIRQ_OFFSET))
account_system_time(p, HARDIRQ_OFFSET, cputime_one_jiffy,
one_jiffy_scaled);
else
account_idle_time(cputime_one_jiffy);
}
/*
* Account time for a transition between system, hard irq or soft irq state.
* Note that this function is called with interrupts enabled.
*/
void account_system_vtime(struct task_struct *tsk)
{
struct thread_info *ti = task_thread_info(tsk);
unsigned long flags;
cputime_t delta_stime;
__u64 now;
local_irq_save(flags);
now = ia64_get_itc();
delta_stime = cycle_to_cputime(ti->ac_stime + (now - ti->ac_stamp));
if (irq_count() || idle_task(smp_processor_id()) != tsk)
account_system_time(tsk, 0, delta_stime, delta_stime);
else
account_idle_time(delta_stime);
ti->ac_stime = 0;
ti->ac_stamp = now;
local_irq_restore(flags);
}
/*
* Called from the context switch with interrupts disabled, to charge all
* accumulated times to the current process, and to prepare accounting on
* the next process.
*/
void ia64_account_on_switch(struct task_struct *prev, struct task_struct *next)
{
struct thread_info *pi = task_thread_info(prev);
struct thread_info *ni = task_thread_info(next);
cputime_t delta_stime, delta_utime;
__u64 now;
now = ia64_get_itc();
delta_stime = cycle_to_cputime(pi->ac_stime + (now - pi->ac_stamp));
if (idle_task(smp_processor_id()) != prev)
account_system_time(prev, 0, delta_stime, delta_stime);
else
account_idle_time(delta_stime);
if (pi->ac_utime) {
delta_utime = cycle_to_cputime(pi->ac_utime);
account_user_time(prev, delta_utime, delta_utime);
}
pi->ac_stamp = ni->ac_stamp = now;
ni->ac_stime = ni->ac_utime = 0;
}
void vtime_account_system(struct task_struct *tsk)
{
cputime_t delta = vtime_delta(tsk);
account_system_time(tsk, 0, delta, delta);
}
/**
* nohz_restart_sched_tick - restart the idle tick from the idle task
*
* Restart the idle tick when the CPU is woken up from idle
*/
void tick_nohz_restart_sched_tick(void)
{
int cpu = smp_processor_id();
struct tick_sched *ts = &per_cpu(tick_cpu_sched, cpu);
unsigned long ticks;
ktime_t now, delta;
if (!ts->tick_stopped)
return;
/* Update jiffies first */
now = ktime_get();
local_irq_disable();
tick_do_update_jiffies64(now);
cpu_clear(cpu, nohz_cpu_mask);
/* Account the idle time */
delta = ktime_sub(now, ts->idle_entrytime);
ts->idle_sleeptime = ktime_add(ts->idle_sleeptime, delta);
/*
* We stopped the tick in idle. Update process times would miss the
* time we slept as update_process_times does only a 1 tick
* accounting. Enforce that this is accounted to idle !
*/
ticks = jiffies - ts->idle_jiffies;
/*
* We might be one off. Do not randomly account a huge number of ticks!
*/
if (ticks && ticks < LONG_MAX) {
add_preempt_count(HARDIRQ_OFFSET);
account_system_time(current, HARDIRQ_OFFSET,
jiffies_to_cputime(ticks));
sub_preempt_count(HARDIRQ_OFFSET);
}
/*
* Cancel the scheduled timer and restore the tick
*/
ts->tick_stopped = 0;
hrtimer_cancel(&ts->sched_timer);
ts->sched_timer.expires = ts->idle_tick;
while (1) {
/* Forward the time to expire in the future */
hrtimer_forward(&ts->sched_timer, now, tick_period);
if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
hrtimer_start(&ts->sched_timer,
ts->sched_timer.expires,
HRTIMER_MODE_ABS);
/* Check, if the timer was already in the past */
if (hrtimer_active(&ts->sched_timer))
break;
} else {
if (!tick_program_event(ts->sched_timer.expires, 0))
break;
}
/* Update jiffies and reread time */
tick_do_update_jiffies64(now);
now = ktime_get();
}
local_irq_enable();
}
static void __vtime_account_system(struct task_struct *tsk)
{
cputime_t delta_cpu = get_vtime_delta(tsk);
account_system_time(tsk, irq_count(), delta_cpu, cputime_to_scaled(delta_cpu));
}