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| author | davide <davide@FreeBSD.org> | 2013-02-28 10:46:54 +0000 |
|---|---|---|
| committer | davide <davide@FreeBSD.org> | 2013-02-28 10:46:54 +0000 |
| commit | 2bf12d0c7ceced74a813d6940dd07310a11d6a2a (patch) | |
| tree | 33c7f3089361e0ab5379fdc8445540c6eeb03ed0 /sys/kern/kern_clocksource.c | |
| parent | f3c985cbe184c9d4c31d0e7140c146768a82833c (diff) | |
| download | FreeBSD-src-2bf12d0c7ceced74a813d6940dd07310a11d6a2a.zip FreeBSD-src-2bf12d0c7ceced74a813d6940dd07310a11d6a2a.tar.gz | |
MFcalloutng:
When CPU becomes idle, cpu_idleclock() calculates time to the next timer
event in order to reprogram hw timer. Return that time in sbintime_t to
the caller and pass it to acpi_cpu_idle(), where it can be used as one
more factor (quite precise) to extimate furter sleep time and choose
optimal sleep state. This is a preparatory change for further callout
improvements will be committed in the next days.
The commmit is not targeted for MFC.
Diffstat (limited to 'sys/kern/kern_clocksource.c')
| -rw-r--r-- | sys/kern/kern_clocksource.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/sys/kern/kern_clocksource.c b/sys/kern/kern_clocksource.c index 33f21e9..ac7e2de 100644 --- a/sys/kern/kern_clocksource.c +++ b/sys/kern/kern_clocksource.c @@ -767,7 +767,7 @@ cpu_stopprofclock(void) /* * Switch to idle mode (all ticks handled). */ -void +sbintime_t cpu_idleclock(void) { struct bintime now, t; @@ -779,7 +779,7 @@ cpu_idleclock(void) || curcpu == CPU_FIRST() #endif ) - return; + return (-1); state = DPCPU_PTR(timerstate); if (periodic) now = state->now; @@ -795,6 +795,8 @@ cpu_idleclock(void) if (!periodic) loadtimer(&now, 0); ET_HW_UNLOCK(state); + bintime_sub(&t, &now); + return (MAX(bttosbt(t), 0)); } /* |
