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.

1 files changed, 10 insertions, 9 deletions

diff --git a/sys/amd64/amd64/machdep.c b/sys/amd64/amd64/machdep.c
index abce826..1d7178f 100644
--- a/sys/amd64/amd64/machdep.c
+++ b/sys/amd64/amd64/machdep.c
@@ -658,7 +658,7 @@ cpu_halt(void)
 		halt();
 }
 
-void (*cpu_idle_hook)(void) = NULL;	/* ACPI idle hook. */
+void (*cpu_idle_hook)(sbintime_t) = NULL;	/* ACPI idle hook. */
 static int	cpu_ident_amdc1e = 0;	/* AMD C1E supported. */
 static int	idle_mwait = 1;		/* Use MONITOR/MWAIT for short idle. */
 TUNABLE_INT("machdep.idle_mwait", &idle_mwait);
@@ -670,7 +670,7 @@ SYSCTL_INT(_machdep, OID_AUTO, idle_mwait, CTLFLAG_RW, &idle_mwait,
 #define	STATE_SLEEPING	0x2
 
 static void
-cpu_idle_acpi(int busy)
+cpu_idle_acpi(sbintime_t sbt)
 {
 	int *state;
 
@@ -682,14 +682,14 @@ cpu_idle_acpi(int busy)
 	if (sched_runnable())
 		enable_intr();
 	else if (cpu_idle_hook)
-		cpu_idle_hook();
+		cpu_idle_hook(sbt);
 	else
 		__asm __volatile("sti; hlt");
 	*state = STATE_RUNNING;
 }
 
 static void
-cpu_idle_hlt(int busy)
+cpu_idle_hlt(sbintime_t sbt)
 {
 	int *state;
 
@@ -730,7 +730,7 @@ cpu_idle_hlt(int busy)
 #define	MWAIT_C4	0x30
 
 static void
-cpu_idle_mwait(int busy)
+cpu_idle_mwait(sbintime_t sbt)
 {
 	int *state;
 
@@ -753,7 +753,7 @@ cpu_idle_mwait(int busy)
 }
 
 static void
-cpu_idle_spin(int busy)
+cpu_idle_spin(sbintime_t sbt)
 {
 	int *state;
 	int i;
@@ -802,12 +802,13 @@ cpu_probe_amdc1e(void)
 	}
 }
 
-void (*cpu_idle_fn)(int) = cpu_idle_acpi;
+void (*cpu_idle_fn)(sbintime_t) = cpu_idle_acpi;
 
 void
 cpu_idle(int busy)
 {
 	uint64_t msr;
+	sbintime_t sbt = -1;
 
 	CTR2(KTR_SPARE2, "cpu_idle(%d) at %d",
 	    busy, curcpu);
@@ -825,7 +826,7 @@ cpu_idle(int busy)
 	/* If we have time - switch timers into idle mode. */
 	if (!busy) {
 		critical_enter();
-		cpu_idleclock();
+		sbt = cpu_idleclock();
 	}
 
 	/* Apply AMD APIC timer C1E workaround. */
@@ -836,7 +837,7 @@ cpu_idle(int busy)
 	}
 
 	/* Call main idle method. */
-	cpu_idle_fn(busy);
+	cpu_idle_fn(sbt);
 
 	/* Switch timers mack into active mode. */
 	if (!busy) {