Create an event (idle_event) which is invoked every time around the

idle loop.  Machine-dependant code can elect to eg. take power-saving
actions when this event is invoked.

1 files changed, 7 insertions, 0 deletions

diff --git a/sys/kern/kern_idle.c b/sys/kern/kern_idle.c
index d9f55ae..1a95e28 100644
--- a/sys/kern/kern_idle.c
+++ b/sys/kern/kern_idle.c
@@ -18,6 +18,7 @@
 #include <sys/unistd.h>
 #include <sys/kthread.h>
 #include <sys/queue.h>
+#include <sys/eventhandler.h>
 #include <vm/vm.h>
 #include <vm/vm_extern.h>
 #ifdef KTRACE
@@ -44,6 +45,8 @@ SYSINIT(idle_setup, SI_SUB_SCHED_IDLE, SI_ORDER_FIRST, idle_setup, NULL)
 
 static void idle_proc(void *dummy);
 
+EVENTHANDLER_FAST_DEFINE(idle_event, idle_eventhandler_t);
+
 /*
  * setup per-cpu idle process contexts
  */
@@ -88,9 +91,13 @@ idle_proc(void *dummy)
 		 * This is a good place to put things to be done in
 		 * the background, including sanity checks.
 		 */
+
 			if (count++ < 0)
 				CTR0(KTR_PROC, "idle_proc: timed out waiting"
 				    " for a process");
+
+			/* call out to any cpu-becoming-idle events */
+			EVENTHANDLER_FAST_INVOKE(idle_event, count);
 		}
 
 		mtx_enter(&sched_lock, MTX_SPIN);