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Commit 18e4e36c authored by Ingo Molnar's avatar Ingo Molnar
Browse files

sched: eliminate scd->prev_raw 



eliminate prev_raw and use tick_raw instead.

It's enough to base the current time on the scheduler tick timestamp
alone - the monotonicity and maximum checks will prevent any damage.

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Acked-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: default avatarMike Galbraith <efault@gmx.de>
parent 50526968

kernel/sched_clock.c

+1 −5
Original line number Diff line number Diff line
@@ -53,7 +53,6 @@ struct sched_clock_data { 
	raw_spinlock_t		lock;



	unsigned long		tick_jiffies;

	u64			prev_raw;

	u64			tick_raw;

	u64			tick_gtod;

	u64			clock;
@@ -84,7 +83,6 @@ void sched_clock_init(void) 


		scd->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED;

		scd->tick_jiffies = now_jiffies;

		scd->prev_raw = 0;

		scd->tick_raw = 0;

		scd->tick_gtod = ktime_now;

		scd->clock = ktime_now;
@@ -105,7 +103,7 @@ static void __update_sched_clock(struct sched_clock_data *scd, u64 now) 
	long delta_jiffies = now_jiffies - scd->tick_jiffies;

	u64 clock = scd->clock;

	u64 min_clock, max_clock;

	s64 delta = now - scd->prev_raw;

	s64 delta = now - scd->tick_raw;



	WARN_ON_ONCE(!irqs_disabled());

	min_clock = scd->tick_gtod + delta_jiffies * TICK_NSEC;
@@ -130,7 +128,6 @@ static void __update_sched_clock(struct sched_clock_data *scd, u64 now) 
	if (unlikely(clock < min_clock))

		clock = min_clock;



	scd->prev_raw = now;

	scd->tick_jiffies = now_jiffies;

	scd->clock = clock;

}
@@ -234,7 +231,6 @@ void sched_clock_idle_wakeup_event(u64 delta_ns) 
	 * rq clock:

	 */

	__raw_spin_lock(&scd->lock);

	scd->prev_raw = now;

	scd->clock += delta_ns;

	__raw_spin_unlock(&scd->lock);