UDP: further performance improvements on tx

Cumulative throughput while running 64
  netperf -H $DUT -t UDP_STREAM -- -m 1
on a 2x8x2 SKL went from 1.1Mpps to 2.5Mpps

Single stream throughput increases from 910kpps to 1.18Mpps

Baseline:
https://people.freebsd.org/~mmacy/2018.05.11/udpsender2.svg

- Protect read access to global ifnet list with epoch
https://people.freebsd.org/~mmacy/2018.05.11/udpsender3.svg

- Protect short lived ifaddr references with epoch
https://people.freebsd.org/~mmacy/2018.05.11/udpsender4.svg

- Convert if_afdata read lock path to epoch
https://people.freebsd.org/~mmacy/2018.05.11/udpsender5.svg

A fix for the inpcbhash contention is pending sufficient time
on a canary at LLNW.

Reviewed by:	gallatin
Sponsored by:	Limelight Networks
Differential Revision:	https://reviews.freebsd.org/D15409

1 files changed, 5 insertions, 5 deletions

diff --git a/sys/nfs/bootp_subr.c b/sys/nfs/bootp_subr.c
index 8bf89850fa5c..d7657155f55d 100644
--- a/sys/nfs/bootp_subr.c
+++ b/sys/nfs/bootp_subr.c
@@ -409,12 +409,12 @@ bootpboot_p_iflist(void)
 
 	printf("Interface list:\n");
 	IFNET_RLOCK();
-	for (ifp = TAILQ_FIRST(&V_ifnet);
+	for (ifp = CK_STAILQ_FIRST(&V_ifnet);
 	     ifp != NULL;
-	     ifp = TAILQ_NEXT(ifp, if_link)) {
+	     ifp = CK_STAILQ_NEXT(ifp, if_link)) {
 		for (ifa = CK_STAILQ_FIRST(&ifp->if_addrhead);
 		     ifa != NULL;
-		     ifa = TAILQ_NEXT(ifa, ifa_link))
+		     ifa = CK_STAILQ_NEXT(ifa, ifa_link))
 			if (ifa->ifa_addr->sa_family == AF_INET)
 				bootpboot_p_if(ifp, ifa);
 	}
@@ -1637,7 +1637,7 @@ bootpc_init(void)
 	 */
 	ifcnt = 0;
 	IFNET_RLOCK();
-	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
+	CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
 		if ((ifp->if_flags &
 		     (IFF_LOOPBACK | IFF_POINTOPOINT | IFF_BROADCAST)) !=
 		    IFF_BROADCAST)
@@ -1660,7 +1660,7 @@ bootpc_init(void)
 retry:
 	ifctx = STAILQ_FIRST(&gctx->interfaces);
 	IFNET_RLOCK();
-	TAILQ_FOREACH(ifp, &V_ifnet, if_link) {
+	CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
 		if (ifctx == NULL)
 			break;
 #ifdef BOOTP_WIRED_TO