提交 b04a0f4c 编写于 作者: I Ingo Molnar

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: NIngo Molnar <mingo@elte.hu>
上级 a4ac01c3
......@@ -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;
......
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