Make kevent(2) periodic timer events more reliably periodic. The event

callout is now scheduled using the C_ABSOLUTE flag, and the absolute time
of each event is calculated as the time the previous event was scheduled
for plus the interval.  This ensures that latency in processing a given
event doesn't perturb the arrival time of any subsequent events.

Reviewed by:	jhb

1 files changed, 1 insertions, 0 deletions

diff --git a/sys/sys/event.h b/sys/sys/event.h
index 47ebd76..c712f76 100644
--- a/sys/sys/event.h
+++ b/sys/sys/event.h
@@ -221,6 +221,7 @@ struct knote {
 		struct		proc *p_proc;	/* proc pointer */
 		struct		aiocblist *p_aio;	/* AIO job pointer */
 		struct		aioliojob *p_lio;	/* LIO job pointer */
+		sbintime_t	*p_nexttime;	/* next timer event fires at */
 		void		*p_v;		/* generic other pointer */
 	} kn_ptr;
 	struct			filterops *kn_fop;