2 files changed, 13 insertions, 2 deletions

diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 278f46f5011b..fafbe163e2b5 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -3442,7 +3442,7 @@ int __init ip_rt_init(void)
                 printk(KERN_ERR "Unable to create route proc files\n");
 #ifdef CONFIG_XFRM
         xfrm_init();
-        xfrm4_init();
+        xfrm4_init(ip_rt_max_size);
 #endif
         rtnl_register(PF_INET, RTM_GETROUTE, inet_rtm_getroute, NULL);
 
diff --git a/net/ipv4/xfrm4_policy.c b/net/ipv4/xfrm4_policy.c
index 26496babdf3a..1ba44742ebbf 100644
--- a/net/ipv4/xfrm4_policy.c
+++ b/net/ipv4/xfrm4_policy.c
@@ -290,10 +290,21 @@ static void __exit xfrm4_policy_fini(void)
         xfrm_policy_unregister_afinfo(&xfrm4_policy_afinfo);
 }
 
-void __init xfrm4_init(void)
+void __init xfrm4_init(int rt_max_size)
 {
         xfrm4_state_init();
         xfrm4_policy_init();
+        /*
+         * Select a default value for the gc_thresh based on the main route
+         * table hash size.  It seems to me the worst case scenario is when
+         * we have ipsec operating in transport mode, in which we create a
+         * dst_entry per socket.  The xfrm gc algorithm starts trying to remove
+         * entries at gc_thresh, and prevents new allocations as 2*gc_thresh
+         * so lets set an initial xfrm gc_thresh value at the rt_max_size/2.
+         * That will let us store an ipsec connection per route table entry,
+         * and start cleaning when were 1/2 full
+         */
+        xfrm4_dst_ops.gc_thresh = rt_max_size/2;
         sysctl_hdr = register_net_sysctl_table(&init_net, net_ipv4_ctl_path,
                                                 xfrm4_policy_table);
 }