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authordavide <davide@FreeBSD.org>2013-02-28 10:46:54 +0000
committerdavide <davide@FreeBSD.org>2013-02-28 10:46:54 +0000
commit2bf12d0c7ceced74a813d6940dd07310a11d6a2a (patch)
tree33c7f3089361e0ab5379fdc8445540c6eeb03ed0 /sys/dev
parentf3c985cbe184c9d4c31d0e7140c146768a82833c (diff)
downloadFreeBSD-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/dev')
-rw-r--r--sys/dev/acpica/acpi_cpu.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/sys/dev/acpica/acpi_cpu.c b/sys/dev/acpica/acpi_cpu.c
index 7f008f7..df4c4c2 100644
--- a/sys/dev/acpica/acpi_cpu.c
+++ b/sys/dev/acpica/acpi_cpu.c
@@ -168,7 +168,7 @@ static int acpi_cpu_cx_cst(struct acpi_cpu_softc *sc);
static void acpi_cpu_startup(void *arg);
static void acpi_cpu_startup_cx(struct acpi_cpu_softc *sc);
static void acpi_cpu_cx_list(struct acpi_cpu_softc *sc);
-static void acpi_cpu_idle(void);
+static void acpi_cpu_idle(sbintime_t sbt);
static void acpi_cpu_notify(ACPI_HANDLE h, UINT32 notify, void *context);
static int acpi_cpu_quirks(void);
static int acpi_cpu_usage_sysctl(SYSCTL_HANDLER_ARGS);
@@ -954,13 +954,13 @@ acpi_cpu_startup_cx(struct acpi_cpu_softc *sc)
* interrupts are re-enabled.
*/
static void
-acpi_cpu_idle()
+acpi_cpu_idle(sbintime_t sbt)
{
struct acpi_cpu_softc *sc;
struct acpi_cx *cx_next;
uint64_t cputicks;
uint32_t start_time, end_time;
- int bm_active, cx_next_idx, i;
+ int bm_active, cx_next_idx, i, us;
/*
* Look up our CPU id to get our softc. If it's NULL, we'll use C1
@@ -980,13 +980,16 @@ acpi_cpu_idle()
}
/* Find the lowest state that has small enough latency. */
+ us = sc->cpu_prev_sleep;
+ if (sbt >= 0 && us > sbt / SBT_1US)
+ us = sbt / SBT_1US;
cx_next_idx = 0;
if (cpu_disable_deep_sleep)
i = min(sc->cpu_cx_lowest, sc->cpu_non_c3);
else
i = sc->cpu_cx_lowest;
for (; i >= 0; i--) {
- if (sc->cpu_cx_states[i].trans_lat * 3 <= sc->cpu_prev_sleep) {
+ if (sc->cpu_cx_states[i].trans_lat * 3 <= us) {
cx_next_idx = i;
break;
}
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