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Commit 41b86e9c authored by Ingo Molnar's avatar Ingo Molnar
Browse files

sched: make posix-cpu-timers use CFS's accounting information 



update the posix-cpu-timers code to use CFS's CPU accounting information.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 20d315d4

include/linux/sched.h

+3 −2
Original line number Diff line number Diff line
@@ -482,7 +482,8 @@ struct signal_struct { 
	 * from jiffies_to_ns(utime + stime) if sched_clock uses something

	 * other than jiffies.)

	 */

	unsigned long long sched_time;

	unsigned long sched_time;

	unsigned long long sum_sched_runtime;



	/*

	 * We don't bother to synchronize most readers of this at all,
@@ -1308,7 +1309,7 @@ static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask) 


extern unsigned long long sched_clock(void);

extern unsigned long long

current_sched_time(const struct task_struct *current_task);

task_sched_runtime(struct task_struct *task);



/* sched_exec is called by processes performing an exec */

#ifdef CONFIG_SMP

kernel/posix-cpu-timers.c

+17 −17
Original line number Diff line number Diff line
@@ -161,7 +161,7 @@ static inline cputime_t virt_ticks(struct task_struct *p) 
}

static inline unsigned long long sched_ns(struct task_struct *p)

{

	return (p == current) ? current_sched_time(p) : p->sched_time;

	return task_sched_runtime(p);

}



int posix_cpu_clock_getres(const clockid_t which_clock, struct timespec *tp)
@@ -246,10 +246,10 @@ static int cpu_clock_sample_group_locked(unsigned int clock_idx, 
		} while (t != p);

		break;

	case CPUCLOCK_SCHED:

		cpu->sched = p->signal->sched_time;

		cpu->sched = p->signal->sum_sched_runtime;

		/* Add in each other live thread.  */

		while ((t = next_thread(t)) != p) {

			cpu->sched += t->sched_time;

			cpu->sched += t->se.sum_exec_runtime;

		}

		cpu->sched += sched_ns(p);

		break;
@@ -422,7 +422,7 @@ int posix_cpu_timer_del(struct k_itimer *timer) 
 */

static void cleanup_timers(struct list_head *head,

			   cputime_t utime, cputime_t stime,

			   unsigned long long sched_time)

			   unsigned long long sum_exec_runtime)

{

	struct cpu_timer_list *timer, *next;

	cputime_t ptime = cputime_add(utime, stime);
@@ -451,10 +451,10 @@ static void cleanup_timers(struct list_head *head, 
	++head;

	list_for_each_entry_safe(timer, next, head, entry) {

		list_del_init(&timer->entry);

		if (timer->expires.sched < sched_time) {

		if (timer->expires.sched < sum_exec_runtime) {

			timer->expires.sched = 0;

		} else {

			timer->expires.sched -= sched_time;

			timer->expires.sched -= sum_exec_runtime;

		}

	}

}
@@ -467,7 +467,7 @@ static void cleanup_timers(struct list_head *head, 
void posix_cpu_timers_exit(struct task_struct *tsk)

{

	cleanup_timers(tsk->cpu_timers,

		       tsk->utime, tsk->stime, tsk->sched_time);

		       tsk->utime, tsk->stime, tsk->se.sum_exec_runtime);



}

void posix_cpu_timers_exit_group(struct task_struct *tsk)
@@ -475,7 +475,7 @@ void posix_cpu_timers_exit_group(struct task_struct *tsk) 
	cleanup_timers(tsk->signal->cpu_timers,

		       cputime_add(tsk->utime, tsk->signal->utime),

		       cputime_add(tsk->stime, tsk->signal->stime),

		       tsk->sched_time + tsk->signal->sched_time);

		     tsk->se.sum_exec_runtime + tsk->signal->sum_sched_runtime);

}
@@ -536,7 +536,7 @@ static void process_timer_rebalance(struct task_struct *p, 
		nsleft = max_t(unsigned long long, nsleft, 1);

		do {

			if (likely(!(t->flags & PF_EXITING))) {

				ns = t->sched_time + nsleft;

				ns = t->se.sum_exec_runtime + nsleft;

				if (t->it_sched_expires == 0 ||

				    t->it_sched_expires > ns) {

					t->it_sched_expires = ns;
@@ -1004,7 +1004,7 @@ static void check_thread_timers(struct task_struct *tsk, 
		struct cpu_timer_list *t = list_first_entry(timers,

						      struct cpu_timer_list,

						      entry);

		if (!--maxfire || tsk->sched_time < t->expires.sched) {

		if (!--maxfire || tsk->se.sum_exec_runtime < t->expires.sched) {

			tsk->it_sched_expires = t->expires.sched;

			break;

		}
@@ -1024,7 +1024,7 @@ static void check_process_timers(struct task_struct *tsk, 
	int maxfire;

	struct signal_struct *const sig = tsk->signal;

	cputime_t utime, stime, ptime, virt_expires, prof_expires;

	unsigned long long sched_time, sched_expires;

	unsigned long long sum_sched_runtime, sched_expires;

	struct task_struct *t;

	struct list_head *timers = sig->cpu_timers;
@@ -1044,12 +1044,12 @@ static void check_process_timers(struct task_struct *tsk, 
	 */

	utime = sig->utime;

	stime = sig->stime;

	sched_time = sig->sched_time;

	sum_sched_runtime = sig->sum_sched_runtime;

	t = tsk;

	do {

		utime = cputime_add(utime, t->utime);

		stime = cputime_add(stime, t->stime);

		sched_time += t->sched_time;

		sum_sched_runtime += t->se.sum_exec_runtime;

		t = next_thread(t);

	} while (t != tsk);

	ptime = cputime_add(utime, stime);
@@ -1090,7 +1090,7 @@ static void check_process_timers(struct task_struct *tsk, 
		struct cpu_timer_list *t = list_first_entry(timers,

						      struct cpu_timer_list,

						      entry);

		if (!--maxfire || sched_time < t->expires.sched) {

		if (!--maxfire || sum_sched_runtime < t->expires.sched) {

			sched_expires = t->expires.sched;

			break;

		}
@@ -1182,7 +1182,7 @@ static void check_process_timers(struct task_struct *tsk, 
		virt_left = cputime_sub(virt_expires, utime);

		virt_left = cputime_div_non_zero(virt_left, nthreads);

		if (sched_expires) {

			sched_left = sched_expires - sched_time;

			sched_left = sched_expires - sum_sched_runtime;

			do_div(sched_left, nthreads);

			sched_left = max_t(unsigned long long, sched_left, 1);

		} else {
@@ -1208,7 +1208,7 @@ static void check_process_timers(struct task_struct *tsk, 
				t->it_virt_expires = ticks;

			}



			sched = t->sched_time + sched_left;

			sched = t->se.sum_exec_runtime + sched_left;

			if (sched_expires && (t->it_sched_expires == 0 ||

					      t->it_sched_expires > sched)) {

				t->it_sched_expires = sched;
@@ -1300,7 +1300,7 @@ void run_posix_cpu_timers(struct task_struct *tsk) 


	if (UNEXPIRED(prof) && UNEXPIRED(virt) &&

	    (tsk->it_sched_expires == 0 ||

	     tsk->sched_time < tsk->it_sched_expires))

	     tsk->se.sum_exec_runtime < tsk->it_sched_expires))

		return;



#undef	UNEXPIRED

kernel/sched.c

+13 −23
Original line number Diff line number Diff line
@@ -3156,28 +3156,23 @@ DEFINE_PER_CPU(struct kernel_stat, kstat); 
EXPORT_PER_CPU_SYMBOL(kstat);



/*

 * This is called on clock ticks and on context switches.

 * Bank in p->sched_time the ns elapsed since the last tick or switch.

 * Return p->sum_exec_runtime plus any more ns on the sched_clock

 * that have not yet been banked in case the task is currently running.

 */

static inline void

update_cpu_clock(struct task_struct *p, struct rq *rq, unsigned long long now)

unsigned long long task_sched_runtime(struct task_struct *p)

{

	p->sched_time += now - p->last_ran;

	p->last_ran = rq->most_recent_timestamp = now;

}



/*

 * Return current->sched_time plus any more ns on the sched_clock

 * that have not yet been banked.

 */

unsigned long long current_sched_time(const struct task_struct *p)

{

	unsigned long long ns;

	unsigned long flags;

	u64 ns, delta_exec;

	struct rq *rq;



	local_irq_save(flags);

	ns = p->sched_time + sched_clock() - p->last_ran;

	local_irq_restore(flags);

	rq = task_rq_lock(p, &flags);

	ns = p->se.sum_exec_runtime;

	if (rq->curr == p) {

		delta_exec = rq_clock(rq) - p->se.exec_start;

		if ((s64)delta_exec > 0)

			ns += delta_exec;

	}

	task_rq_unlock(rq, &flags);



	return ns;

}
@@ -3360,14 +3355,11 @@ static void task_running_tick(struct rq *rq, struct task_struct *p) 
 */

void scheduler_tick(void)

{

	unsigned long long now = sched_clock();

	struct task_struct *p = current;

	int cpu = smp_processor_id();

	int idle_at_tick = idle_cpu(cpu);

	struct rq *rq = cpu_rq(cpu);



	update_cpu_clock(p, rq, now);



	if (!idle_at_tick)

		task_running_tick(rq, p);

#ifdef CONFIG_SMP
@@ -3550,8 +3542,6 @@ asmlinkage void __sched schedule(void) 
	clear_tsk_need_resched(prev);

	rcu_qsctr_inc(task_cpu(prev));



	update_cpu_clock(prev, rq, now);



	prev->sleep_avg -= run_time;

	if ((long)prev->sleep_avg <= 0)

		prev->sleep_avg = 0;