--- linux/arch/um/kernel/time_kern.c.orig	Mon Sep 23 17:01:16 2002
+++ linux/arch/um/kernel/time_kern.c	Mon Sep 23 16:46:42 2002
@@ -19,12 +19,24 @@
 
 extern rwlock_t xtime_lock;
 
+#ifdef CONFIG_UM_PRECISION_CLOCK
+
+#define 	HZ_INTERVAL 	1000000/HZ
+long CPUKHZ; 			/* eg. 996701	  */
+double MULF; 			/* 1000/996701	  */
+unsigned long prev_tsc=0,tsc=0;	/* Lag boundaries */
+static long delta=0;   		/* Deviation per interval */
+extern unsigned long time_stamp();
+
+#endif
+
 int hz(void)
 {
 	return(HZ);
 }
 
 int timer_irq_inited = 0;
+int first_tick = 0;
 
 /* kern_timer_on and missed_ticks are modified after kernel memory has been 
  * write-protected, so this puts it in a section which will be left 
@@ -35,10 +47,34 @@
 
 void timer_irq(struct uml_pt_regs *regs)
 {
+	long ms;
 	int ticks = missed_ticks;
 
         if(!timer_irq_inited) return;
 	missed_ticks = 0;
+
+#ifdef CONFIG_UM_PRECISION_CLOCK
+	if (first_tick) /* We've had 1 tick */{
+		tsc = time_stamp();
+ 		ms = (tsc - prev_tsc) * MULF;
+        	prev_tsc = tsc;
+        	delta += ms - HZ_INTERVAL;
+        	if (delta > HZ_INTERVAL) {
+               		ticks++;
+                	delta-=HZ_INTERVAL;
+        	}
+        	else
+        	if ((delta < -HZ_INTERVAL) && (ticks /*Paranoia*/)) {
+                	ticks--;
+                	delta+=HZ_INTERVAL;
+        	}
+	}
+	else {
+		prev_tsc = time_stamp();
+		first_tick = 1;
+	}
+#endif
+
 	while(ticks--) do_IRQ(TIMER_IRQ, regs);
 }
 
--- linux/arch/um/kernel/time.c.orig	Mon Sep 23 17:01:39 2002
+++ linux/arch/um/kernel/time.c	Mon Sep 23 17:19:33 2002
@@ -1,6 +1,7 @@
 /* 
  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.com)
  * Licensed under the GPL
+ *
  */
 
 #include <stdio.h>
@@ -15,8 +16,24 @@
 #include "process.h"
 #include "signal_user.h"
 
-extern struct timeval xtime;
+#ifdef CONFIG_UM_PRECISION_CLOCK
+extern long CPUKHZ; 
+extern double MULF; 	
+extern unsigned long prev_tsc; 
+#endif
+
+/* This should be inside the ifdef, but gcc 2.95/96 gives a linker error
+ * in time_kern.c even if it's commented out
+ */
+
+inline unsigned long time_stamp(void)
+{
+	unsigned long counter;
+	asm ("rdtsc":"=a"(counter)::"edx");
+	return counter;
+}
 
+extern struct timeval xtime;
 void timer_handler(int sig, struct uml_pt_regs *regs)
 {
 	timer_irq(regs);
@@ -64,8 +81,13 @@
 
 void user_time_init(void)
 {
+#ifdef CONFIG_UM_PRECISION_CLOCK
+	CPUKHZ = get_host_khz();
+	MULF = 1000.0 / CPUKHZ;
+#endif
 	if(signal(SIGVTALRM, (__sighandler_t) alarm_handler) == SIG_ERR)
 		panic("Couldn't set SIGVTALRM handler");
+
 	set_interval(ITIMER_VIRTUAL);
 }
 
--- linux/arch/um/kernel/user_util.c.orig	Mon Sep 23 17:02:05 2002
+++ linux/arch/um/kernel/user_util.c	Mon Sep 23 12:22:30 2002
@@ -31,6 +31,8 @@
 #include "helper.h"
 
 #define COMMAND_LINE_SIZE _POSIX_ARG_MAX
+#define CPU_PROC_MHZ_HEADER "cpu MHz\t\t: "
+#define CPU_PROC_MHZ_HEADER_LEN 11
 
 char saved_command_line[COMMAND_LINE_SIZE] = { 0 };
 char command_line[COMMAND_LINE_SIZE] = { 0 };
@@ -139,6 +141,30 @@
 	}
 }
 
+long get_host_khz()
+{
+	char mhzline[27];
+	double mhz;
+	FILE *fp = fopen("/proc/cpuinfo", "r");
+	if (!fp) goto bad_fd;
+
+	while (!feof(fp)) {
+		fgets(mhzline, 19, fp);
+		if (!mhzline)
+			goto bad;
+		if (strncmp(mhzline, CPU_PROC_MHZ_HEADER, 
+				CPU_PROC_MHZ_HEADER_LEN) == 0) {
+			fclose(fp);
+			return (atof(mhzline + CPU_PROC_MHZ_HEADER_LEN)*1000);
+		}
+	}
+
+bad:
+	fclose(fp);
+bad_fd:
+	return -1;
+}
+
 int clone_and_wait(int (*fn)(void *), void *arg, void *sp, int flags)
 {
 	int pid;