Index: net/bpf.c
===================================================================
RCS file: /home/ncvs/src/sys/net/bpf.c,v
retrieving revision 1.185
diff -u -r1.185 bpf.c
--- net/bpf.c	25 Dec 2007 13:24:02 -0000	1.185
+++ net/bpf.c	6 Feb 2008 14:06:03 -0000
@@ -132,6 +132,9 @@
 static int bpf_maxinsns = BPF_MAXINSNS;
 SYSCTL_INT(_net_bpf, OID_AUTO, maxinsns, CTLFLAG_RW,
     &bpf_maxinsns, 0, "Maximum bpf program instructions");
+static int bpf_fastts = 0;
+SYSCTL_INT(_net_bpf, OID_AUTO, fastts, CTLFLAG_RW,
+    &bpf_fastts, 0, "Use fast, innacurate timestamps based on ticks");
 SYSCTL_NODE(_net_bpf, OID_AUTO, stats, CTLFLAG_RW,
     bpf_stats_sysctl, "bpf statistics portal");
 
@@ -1268,6 +1271,19 @@
 	return (ready);
 }
 
+static void
+bpf_gettime(struct timeval *tv)
+{
+	if (!bpf_fastts) {
+		microtime(tv);
+		return;
+	}
+	/* just generate a timestamp based on ticks */
+	tv->tv_sec = ticks / tick + boottime.tv_sec;
+	tv->tv_usec = ticks  % tick + boottime.tv_usec;
+	
+}
+
 /*
  * Incoming linkage from device drivers.  Process the packet pkt, of length
  * pktlen, which is stored in a contiguous buffer.  The packet is parsed
@@ -1296,7 +1312,7 @@
 		if (slen != 0) {
 			d->bd_fcount++;
 			if (!gottime) {
-				microtime(&tv);
+				bpf_gettime(&tv);
 				gottime = 1;
 			}
 #ifdef MAC
@@ -1375,7 +1391,7 @@
 		if (slen != 0) {
 			d->bd_fcount++;
 			if (!gottime) {
-				microtime(&tv);
+				bpf_gettime(&tv);
 				gottime = 1;
 			}
 #ifdef MAC
@@ -1430,7 +1446,7 @@
 		if (slen != 0) {
 			d->bd_fcount++;
 			if (!gottime) {
-				microtime(&tv);
+				bpf_gettime(&tv);
 				gottime = 1;
 			}
 #ifdef MAC