Add support for walltimestamp in DTrace.

Submitted by:	Fabian Keil
MFC after:	2 weeks

1 files changed, 20 insertions, 0 deletions

diff --git a/sys/kern/kern_tc.c b/sys/kern/kern_tc.c
index 4a75af5..a08b218 100644
--- a/sys/kern/kern_tc.c
+++ b/sys/kern/kern_tc.c
@@ -122,6 +122,8 @@ SYSCTL_INT(_kern_timecounter, OID_AUTO, stepwarnings, CTLFLAG_RW,
 static void tc_windup(void);
 static void cpu_tick_calibrate(int);
 
+void dtrace_getnanotime(struct timespec *tsp);
+
 static int
 sysctl_kern_boottime(SYSCTL_HANDLER_ARGS)
 {
@@ -960,6 +962,24 @@ getmicrotime(struct timeval *tvp)
 #endif /* FFCLOCK */
 
 /*
+ * This is a clone of getnanotime and used for walltimestamps.
+ * The dtrace_ prefix prevents fbt from creating probes for
+ * it so walltimestamp can be safely used in all fbt probes.
+ */
+void
+dtrace_getnanotime(struct timespec *tsp)
+{
+	struct timehands *th;
+	u_int gen;
+
+	do {
+		th = timehands;
+		gen = th->th_generation;
+		*tsp = th->th_nanotime;
+	} while (gen == 0 || gen != th->th_generation);
+}
+
+/*
  * System clock currently providing time to the system. Modifiable via sysctl
  * when the FFCLOCK option is defined.
  */