A-Team_Digital_Solutions/android_kernel_motorola_sm6375
Watch
2
0
Fork
You've already forked android_kernel_motorola_sm6375
 0
mirror of https://github.com/BobTheBlinker/android_kernel_motorola_sm6375.git synced 2026-10-28 18:51:56 -04:00
Code Issues Projects Releases Packages Wiki Activity

sched: sched_clock_idle_[sleep|wakeup]_event()

Browse source 
construct a more or less wall-clock time out of sched_clock(), by
using ACPI-idle's existing knowledge about how much time we spent
idling. This allows the rq clock to work around TSC-stops-in-C2,
TSC-gets-corrupted-in-C3 type of problems.

( Besides the scheduler's statistics this also benefits blktrace and
  printk-timestamps as well. )

Furthermore, the precise before-C2/C3-sleep and after-C2/C3-wakeup
callbacks allow the scheduler to get out the most of the period where
the CPU has a reliable TSC. This results in slightly more precise
task statistics.

the ACPI bits were acked by Len.

Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Len Brown <[email protected]>
This commit is contained in:
Ingo Molnar 2007-08-23 15:18:02 +02:00
commit 2aa44d0567
5 changed files with 61 additions and 19 deletions
Download patch file Download diff file Expand all files Collapse all files

41
kernel/sched.c
View file

@ -262,7 +262,8 @@ struct rq {
s64 clock_max_delta;
unsigned int clock_warps, clock_overflows;
unsigned int clock_unstable_events;
u64 idle_clock;
unsigned int clock_deep_idle_events;
u64 tick_timestamp;
atomic_t nr_iowait;
@ -556,18 +557,40 @@ static inline struct rq *this_rq_lock(void)
}
/*
* CPU frequency is/was unstable - start new by setting prev_clock_raw:
* We are going deep-idle (irqs are disabled):
*/
void sched_clock_unstable_event(void)
void sched_clock_idle_sleep_event(void)
{
unsigned long flags;
struct rq *rq;
struct rq *rq = cpu_rq(smp_processor_id());
rq = task_rq_lock(current, &flags);
rq->prev_clock_raw = sched_clock();
rq->clock_unstable_events++;
task_rq_unlock(rq, &flags);
spin_lock(&rq->lock);
__update_rq_clock(rq);
spin_unlock(&rq->lock);
rq->clock_deep_idle_events++;
}
EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event);
/*
* We just idled delta nanoseconds (called with irqs disabled):
*/
void sched_clock_idle_wakeup_event(u64 delta_ns)
{
struct rq *rq = cpu_rq(smp_processor_id());
u64 now = sched_clock();
rq->idle_clock += delta_ns;
/*
* Override the previous timestamp and ignore all
* sched_clock() deltas that occured while we idled,
* and use the PM-provided delta_ns to advance the
* rq clock:
*/
spin_lock(&rq->lock);
rq->prev_clock_raw = now;
rq->clock += delta_ns;
spin_unlock(&rq->lock);
}
EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
/*
* resched_task - mark a task 'to be rescheduled now'.