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Commit b04a0f4c authored by Ingo Molnar's avatar Ingo Molnar
Browse files

sched: add [__]update_rq_clock(rq) 



add the [__]update_rq_clock(rq) functions. (No change in functionality,
just reorganization to prepare for elimination of the heavy 64-bit
timestamp-passing in the scheduler.)

Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent a4ac01c3

kernel/sched.c

+22 −8
Original line number Diff line number Diff line
@@ -318,15 +318,19 @@ static inline int cpu_of(struct rq *rq) 
}



/*

 * Per-runqueue clock, as finegrained as the platform can give us:

 * Update the per-runqueue clock, as finegrained as the platform can give

 * us, but without assuming monotonicity, etc.:

 */

static unsigned long long __rq_clock(struct rq *rq)

static void __update_rq_clock(struct rq *rq)

{

	u64 prev_raw = rq->prev_clock_raw;

	u64 now = sched_clock();

	s64 delta = now - prev_raw;

	u64 clock = rq->clock;



#ifdef CONFIG_SCHED_DEBUG

	WARN_ON_ONCE(cpu_of(rq) != smp_processor_id());

#endif

	/*

	 * Protect against sched_clock() occasionally going backwards:

	 */
@@ -349,17 +353,24 @@ static unsigned long long __rq_clock(struct rq *rq) 


	rq->prev_clock_raw = now;

	rq->clock = clock;

}



	return clock;

static void update_rq_clock(struct rq *rq)

{

	if (likely(smp_processor_id() == cpu_of(rq)))

		__update_rq_clock(rq);

}



static unsigned long long rq_clock(struct rq *rq)

static u64 __rq_clock(struct rq *rq)

{

	int this_cpu = smp_processor_id();

	__update_rq_clock(rq);



	if (this_cpu == cpu_of(rq))

		return __rq_clock(rq);

	return rq->clock;

}



static u64 rq_clock(struct rq *rq)

{

	update_rq_clock(rq);

	return rq->clock;

}
@@ -386,9 +397,12 @@ unsigned long long cpu_clock(int cpu) 
{

	unsigned long long now;

	unsigned long flags;

	struct rq *rq;



	local_irq_save(flags);

	now = rq_clock(cpu_rq(cpu));

	rq = cpu_rq(cpu);

	update_rq_clock(rq);

	now = rq->clock;

	local_irq_restore(flags);



	return now;