Diffstat (limited to 'sys/cddl/dev')
1 files changed, 13 insertions, 10 deletions
diff --git a/sys/cddl/dev/dtrace/aarch64/dtrace_subr.c b/sys/cddl/dev/dtrace/aarch64/dtrace_subr.c
index 6646e51fc191..9bf9f0798bb5 100644
@@ -153,23 +153,26 @@ dtrace_sync(void)
- * DTrace needs a high resolution time function which can
- * be called from a probe context and guaranteed not to have
- * instrumented with probes itself.
+ * DTrace needs a high resolution time function which can be called from a
+ * probe context and guaranteed not to have instrumented with probes itself.
- * Returns nanoseconds since boot.
+ * Returns nanoseconds since some arbitrary point in time (likely SoC reset?).
- struct timespec curtime;
- return (curtime.tv_sec * 1000000000UL + curtime.tv_nsec);
+ uint64_t count, freq;
+ count = READ_SPECIALREG(cntvct_el0);
+ freq = READ_SPECIALREG(cntfrq_el0);
+ return ((1000000000UL * count) / freq);
+ * Return a much lower resolution wallclock time based on the system clock
+ * updated by the timer. If needed, we could add a version interpolated from
+ * the system clock as is the case with dtrace_gethrtime().