==== //depot/projects/netperf/sys/net/netisr.c#2 - /home/robert/p4/projects/netperf/sys/net/netisr.c ====
@@ -60,7 +60,6 @@
 	struct ifqueue	*ni_queue;
 } netisrs[32];
 
-static struct mtx netisr_mtx;
 static void *net_ih;
 
 void
@@ -150,7 +149,7 @@
 		m_freem(m);
 		return;
 	}
-	if (netisr_enable && mtx_trylock(&netisr_mtx)) {
+	if (netisr_enable) {
 		isrstat.isrs_directed++;
 		/*
 		 * One slight problem here is that packets might bypass
@@ -167,7 +166,6 @@
 		if (_IF_QLEN(ni->ni_queue) > 0)
 			isrstat.isrs_bypassed++;
 		ni->ni_handler(m);
-		mtx_unlock(&netisr_mtx);
 	} else {
 		isrstat.isrs_deferred++;
 		if (IF_HANDOFF(ni->ni_queue, m, NULL))
@@ -212,7 +210,6 @@
 	const int polling = 0;
 #endif
 
-	mtx_lock(&netisr_mtx);
 	do {
 		bits = atomic_readandclear_int(&netisr);
 		if (bits == 0)
@@ -237,14 +234,12 @@
 				}
 		}
 	} while (polling);
-	mtx_unlock(&netisr_mtx);
 }
 
 static void
 start_netisr(void *dummy)
 {
 
-	mtx_init(&netisr_mtx, "netisr lock", NULL, MTX_DEF);
 	if (swi_add(NULL, "net", swi_net, NULL, SWI_NET, INTR_MPSAFE, &net_ih))
 		panic("start_netisr");
 }