From 37eacd1a0ff00b08beb61cf7f5d4e4a699e2a5bb Mon Sep 17 00:00:00 2001
From: Sepherosa Ziehau <sephe@dragonflybsd.org>
Date: Sat, 29 Mar 2008 04:45:47 +0000
Subject: [PATCH] Add two tunables to run netisr and udp_thread without mplock,
 so experiment could be conducted under controlled environment. Default values
 of these two tunables are to run netisr/udp_thread with mplock.

---
 sys/net/netisr.c       | 11 ++++++++---
 sys/netinet/ip_demux.c | 11 ++++++++---
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/sys/net/netisr.c b/sys/net/netisr.c
index ad2e972cac..9353c2484a 100644
--- a/sys/net/netisr.c
+++ b/sys/net/netisr.c
@@ -35,7 +35,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $DragonFly: src/sys/net/netisr.c,v 1.38 2008/03/29 03:37:15 sephe Exp $
+ * $DragonFly: src/sys/net/netisr.c,v 1.39 2008/03/29 04:45:47 sephe Exp $
  */
 
 #include <sys/param.h>
@@ -75,6 +75,9 @@ lwkt_port netisr_sync_port;
 
 static int (*netmsg_fwd_port_fn)(lwkt_port_t, lwkt_msg_t);
 
+static int netisr_mpsafe_thread = 0;
+TUNABLE_INT("netisr.mpsafe_thread", &netisr_mpsafe_thread);
+
 /*
  * netisr_afree_rport replymsg function, only used to handle async
  * messages which the sender has abandoned to their fate.
@@ -144,8 +147,10 @@ netisr_init(void)
      * Create default per-cpu threads for generic protocol handling.
      */
     for (i = 0; i < ncpus; ++i) {
-	lwkt_create(netmsg_service_loop, NULL, NULL, &netisr_cpu[i], 0, i,
-		    "netisr_cpu %d", i);
+	lwkt_create(netisr_mpsafe_thread ?
+		    netmsg_service_loop_mpsafe : netmsg_service_loop,
+		    NULL, NULL, &netisr_cpu[i],
+		    0, i, "netisr_cpu %d", i);
 	netmsg_service_port_init(&netisr_cpu[i].td_msgport);
     }
 
diff --git a/sys/netinet/ip_demux.c b/sys/netinet/ip_demux.c
index 6912894f70..9ee55e9138 100644
--- a/sys/netinet/ip_demux.c
+++ b/sys/netinet/ip_demux.c
@@ -30,7 +30,7 @@
  * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- * $DragonFly: src/sys/netinet/ip_demux.c,v 1.38 2008/03/26 14:44:59 sephe Exp $
+ * $DragonFly: src/sys/netinet/ip_demux.c,v 1.39 2008/03/29 04:45:47 sephe Exp $
  */
 
 #include "opt_inet.h"
@@ -64,6 +64,9 @@ extern struct thread netisr_cpu[];
 static struct thread tcp_thread[MAXCPU];
 static struct thread udp_thread[MAXCPU];
 
+static int	udp_mpsafe_thread = 0;
+TUNABLE_INT("net.inet.udp.mpsafe_thread", &udp_mpsafe_thread);
+
 static __inline int
 INP_MPORT_HASH(in_addr_t faddr, in_addr_t laddr,
 	       in_port_t fport, in_port_t lport)
@@ -385,8 +388,10 @@ udp_thread_init(void)
 	int cpu;
 
 	for (cpu = 0; cpu < ncpus2; cpu++) {
-		lwkt_create(netmsg_service_loop, NULL, NULL,
-			&udp_thread[cpu], 0, cpu, "udp_thread %d", cpu);
+		lwkt_create(udp_mpsafe_thread ?
+			    netmsg_service_loop_mpsafe : netmsg_service_loop,
+			    NULL, NULL, &udp_thread[cpu], 0, cpu,
+			    "udp_thread %d", cpu);
 		netmsg_service_port_init(&udp_thread[cpu].td_msgport);
 	}
 }
-- 
2.11.4.GIT