From c9fe6708f95bd69fe62b1565122be25ee017aa76 Mon Sep 17 00:00:00 2001
From: Sepherosa Ziehau <sephe@FreeBSD.org>
Date: Thu, 1 Sep 2016 08:01:13 +0000
Subject: MFC 304202     tcp/lro: Make # of LRO entries tunable

    Reviewed by:    hps, gallatin
    Obtained from:  rrs, gallatin
    Sponsored by:   Netflix (rrs, gallatin), Microsoft (sephe)
    Differential Revision:  https://reviews.freebsd.org/D7499
---
 sys/netinet/tcp_lro.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/sys/netinet/tcp_lro.c b/sys/netinet/tcp_lro.c
index 761d8f323d2a..65e2e3514b99 100644
--- a/sys/netinet/tcp_lro.c
+++ b/sys/netinet/tcp_lro.c
@@ -40,6 +40,7 @@ __FBSDID("$FreeBSD$");
 #include <sys/mbuf.h>
 #include <sys/kernel.h>
 #include <sys/socket.h>
+#include <sys/sysctl.h>
 
 #include <net/if.h>
 #include <net/if_var.h>
@@ -53,6 +54,7 @@ __FBSDID("$FreeBSD$");
 #include <netinet/ip_var.h>
 #include <netinet/tcp.h>
 #include <netinet/tcp_lro.h>
+#include <netinet/tcp_var.h>
 
 #include <netinet6/ip6_var.h>
 
@@ -67,6 +69,14 @@ __FBSDID("$FreeBSD$");
 #define	TCP_LRO_INVALID_CSUM	0x0000
 #endif
 
+SYSCTL_NODE(_net_inet_tcp, OID_AUTO, lro,  CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
+    "TCP LRO");
+
+static unsigned	tcp_lro_entries = LRO_ENTRIES;
+SYSCTL_UINT(_net_inet_tcp_lro, OID_AUTO, entries,
+    CTLFLAG_RDTUN | CTLFLAG_MPSAFE, &tcp_lro_entries, 0,
+    "default number of LRO entries");
+
 int
 tcp_lro_init(struct lro_ctrl *lc)
 {
@@ -81,7 +91,7 @@ tcp_lro_init(struct lro_ctrl *lc)
 	SLIST_INIT(&lc->lro_active);
 
 	error = 0;
-	for (i = 0; i < LRO_ENTRIES; i++) {
+	for (i = 0; i < tcp_lro_entries; i++) {
 		le = (struct lro_entry *)malloc(sizeof(*le), M_DEVBUF,
 		    M_NOWAIT | M_ZERO);
                 if (le == NULL) {
-- 
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