Index: include/cpu.h
===================================================================
RCS file: /cvs/src/sys/arch/amd64/include/cpu.h,v
retrieving revision 1.136
diff -u -p -r1.136 cpu.h
--- include/cpu.h	31 May 2020 06:23:56 -0000	1.136
+++ include/cpu.h	31 May 2020 12:21:36 -0000
@@ -304,7 +304,15 @@ void cpu_unidle(struct cpu_info *);
 #include <machine/cpufunc.h>
 #include <machine/psl.h>
 
-unsigned int cpu_rnd_messybits(void);
+static inline unsigned int
+cpu_rnd_messybits(void)
+{
+	unsigned int hi, lo;
+
+	__asm volatile("rdtsc" : "=d" (hi), "=a" (lo));
+
+        return (hi ^ lo);
+}
 
 #endif /* _KERNEL */
 
Index: amd64/machdep.c
===================================================================
RCS file: /cvs/src/sys/arch/amd64/amd64/machdep.c,v
retrieving revision 1.266
diff -u -p -r1.266 machdep.c
--- amd64/machdep.c	31 May 2020 06:23:56 -0000	1.266
+++ amd64/machdep.c	31 May 2020 12:21:36 -0000
@@ -2055,12 +2055,3 @@ check_context(const struct reg *regs, st
 
 	return 0;
 }
-
-unsigned int
-cpu_rnd_messybits(void)
-{
-	struct timespec ts;
-
-	nanotime(&ts);
-	return (ts.tv_nsec ^ (ts.tv_sec << 20));
-}