diff -burN -X dontdiff linux-2.6.12.2/Makefile linux-2.6.12-ins/Makefile
--- linux-2.6.12.2/Makefile	2005-06-29 16:00:53.000000000 -0700
+++ linux-2.6.12-ins/Makefile	2005-07-25 17:24:36.000000000 -0700
@@ -1,7 +1,7 @@
 VERSION = 2
 PATCHLEVEL = 6
 SUBLEVEL = 12
-EXTRAVERSION = .2
+EXTRAVERSION = .2-ins
 NAME=Woozy Numbat
 
 # *DOCUMENTATION*
diff -burN -X dontdiff linux-2.6.12.2/include/net/timing.h linux-2.6.12-ins/include/net/timing.h
--- linux-2.6.12.2/include/net/timing.h	1969-12-31 16:00:00.000000000 -0800
+++ linux-2.6.12-ins/include/net/timing.h	2005-07-25 17:26:25.000000000 -0700
@@ -0,0 +1,14 @@
+#ifndef _TIMING_H
+#define _TIMING_H
+
+#define tsc(hi,lo) __asm__ __volatile__ ("rdtsc" : "=A" (lo), "=D" (hi))
+
+struct tsc_reg {
+	long hi;
+	long lo;
+};
+
+extern struct tsc_reg inst_start;
+extern struct sk_buff* inst_curpkt;
+
+#endif /* _TIMING_H */
diff -burN -X dontdiff linux-2.6.12.2/net/core/dev.c linux-2.6.12-ins/net/core/dev.c
--- linux-2.6.12.2/net/core/dev.c	2005-06-29 16:00:53.000000000 -0700
+++ linux-2.6.12-ins/net/core/dev.c	2005-08-01 17:41:29.000000000 -0700
@@ -115,6 +115,19 @@
 #endif	/* CONFIG_NET_RADIO */
 #include <asm/current.h>
 
+/* Kernel Instrumentation */
+#ifndef TIMING
+#define TIMING
+#endif
+
+#ifdef TIMING
+#include <net/timing.h> 
+struct sk_buff* inst_curpkt = NULL;	/* Packet to be traced */
+int inst_reset = 0;			/* Used to reset the tracing */
+struct tsc_reg inst_start;
+struct tsc_reg prev_time;
+#endif /* TIMING */
+
 /* This define, if set, will randomly drop a packet when congestion
  * is more than moderate.  It helps fairness in the multi-interface
  * case when one of them is a hog, but it kills performance for the
@@ -1452,6 +1465,38 @@
 	struct softnet_data *queue;
 	unsigned long flags;
 
+#ifdef TIMING
+	/* Packet Timing Instrumentation */
+	struct tsc_reg prev_time, cur_time;
+	prev_time.hi = 0; cur_time.hi = 0;
+
+	if (prev_time.hi == 0) {
+		tsc(prev_time.hi, prev_time.lo);
+	} else {
+		tsc(cur_time.hi, cur_time.lo);
+		__u32 diff = cur_time.lo - prev_time.lo;
+		printk(KERN_INFO "Diff=%u\n", diff);
+		prev_time = cur_time;
+	}
+
+#if 0
+	if (inst_curpkt != NULL && inst_reset > 0) {
+		printk(KERN_INFO "sk_buff %x: Timing RESET\n", (unsigned) skb);
+		inst_curpkt = NULL;
+		inst_start.hi = 0;
+		inst_start.lo = 0;
+	}
+
+	if (inst_curpkt == NULL) {
+		printk(KERN_INFO "sk_buff %x: Start trace", (unsigned) skb);
+		inst_curpkt = skb;
+		tsc(inst_start.hi, inst_start.lo);
+		inst_reset = 0;
+	}
+#endif
+	/* Packet Timing Instrumentation */
+#endif
+
 	/* if netpoll wants it, pretend we never saw it */
 	if (netpoll_rx(skb))
 		return NET_RX_DROP;
@@ -1792,6 +1837,19 @@
 	unsigned long start_time = jiffies;
 	int budget = netdev_max_backlog;
 
+#ifdef TIMING
+	/* Packet Timing Instrumentation */
+	struct tsc_reg cur_time;
+
+	if (prev_time.hi == 0) {
+		tsc(prev_time.hi, prev_time.lo);
+	} else {
+		tsc(cur_time.hi, cur_time.lo);
+		__u32 diff = cur_time.lo - prev_time.lo;
+		printk(KERN_INFO "Diff=%u\n", diff);
+		prev_time = cur_time;
+	}
+#endif
 	
 	local_irq_disable();
 
diff -burN -X dontdiff linux-2.6.12.2/net/ipv4/ip_input.c linux-2.6.12-ins/net/ipv4/ip_input.c
--- linux-2.6.12.2/net/ipv4/ip_input.c	2005-06-29 16:00:53.000000000 -0700
+++ linux-2.6.12-ins/net/ipv4/ip_input.c	2005-07-25 17:55:21.000000000 -0700
@@ -146,6 +146,15 @@
 #include <linux/mroute.h>
 #include <linux/netlink.h>
 
+/* Kernel Instrumentation */
+#ifndef TIMING
+#define TIMING
+#endif
+
+#ifdef TIMING
+#include <net/timing.h>
+#endif
+
 /*
  *	SNMP management statistics
  */
@@ -361,6 +370,19 @@
 {
 	struct iphdr *iph;
 
+#if 0
+#ifdef TIMING
+	/* Packet Timing Instrumentation */
+	if (inst_curpkt != NULL) {
+		struct tsc_reg cur_time;
+		tsc(cur_time.hi, cur_time.lo);
+		printk(KERN_INFO "sk_buff %x: ip_input after %lu usecs\n",
+		       (unsigned) skb,
+		       (__u32) cur_time.lo - inst_start.lo);
+	}
+#endif /* TIMING */
+#endif
+
 	/* When the interface is in promisc. mode, drop all the crap
 	 * that it receives, do not try to analyse it.
 	 */
diff -burN -X dontdiff linux-2.6.12.2/net/ipv4/udp.c linux-2.6.12-ins/net/ipv4/udp.c
--- linux-2.6.12.2/net/ipv4/udp.c	2005-06-29 16:00:53.000000000 -0700
+++ linux-2.6.12-ins/net/ipv4/udp.c	2005-07-25 17:55:55.000000000 -0700
@@ -108,6 +108,15 @@
 #include <net/checksum.h>
 #include <net/xfrm.h>
 
+/* Kernel Intrumentation */
+#ifndef TIMING
+#define TIMING
+#endif
+
+#ifdef TIMING
+#include <net/timing.h>
+#endif
+
 /*
  *	Snmp MIB for the UDP layer
  */
@@ -1133,6 +1142,19 @@
 	if (!pskb_may_pull(skb, sizeof(struct udphdr)))
 		goto no_header;
 
+#if 0
+#ifdef TIMING
+	/* Packet Timing Instrumentation */
+	if (inst_curpkt != NULL) {
+		struct tsc_reg cur_time;
+		tsc(cur_time.hi, cur_time.lo);		
+		printk(KERN_INFO "sk_buff %x: udp_input after %lu usecs\n",
+		       (unsigned) skb, 
+		       (__u32) cur_time.lo - inst_start.lo);
+	}
+#endif /* TIMING */
+#endif
+
 	uh = skb->h.uh;
 
 	ulen = ntohs(uh->len);