PERFORCE change 134436 for review

[John Birrell]

http://perforce.freebsd.org/chv.cgi?CH=134436

Change 134436 by jb at jb_freebsd1 on 2008/01/30 04:47:37

	IFdtrace

Affected files ...

.. //depot/projects/dtrace7/src/sys/amd64/amd64/tsc.c#2 edit

Differences ...

==== //depot/projects/dtrace7/src/sys/amd64/amd64/tsc.c#2 (text+ko) ====

@@ -28,6 +28,7 @@
 __FBSDID("$FreeBSD: src/sys/amd64/amd64/tsc.c,v 1.208 2007/06/04 18:25:01 dwmalone Exp $");
 
 #include "opt_clock.h"
+#include "opt_kdtrace.h"
 
 #include <sys/param.h>
 #include <sys/bus.h>
@@ -44,6 +45,10 @@
 #include <machine/md_var.h>
 #include <machine/specialreg.h>
 
+#ifdef KDTRACE_HOOKS
+#include <sys/dtrace_bsd.h>
+#endif
+
 #include "cpufreq_if.h"
 
 uint64_t	tsc_freq;
@@ -220,3 +225,18 @@
 {
 	return (rdtsc());
 }
+
+#ifdef KDTRACE_HOOKS
+/*
+ * 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.
+ */
+uint64_t
+dtrace_gethrtime()
+{
+	return (rdtsc() * (uint64_t) 1000000000 / tsc_freq);
+}
+#endif