batman-adv: use kmem_cache for translation table

The translation table (global, local) is usually the part of batman-adv
which has the most dynamical allocated objects. Most of them
(tt_local_entry, tt_global_entry, tt_orig_list_entry, tt_change_node,
tt_req_node, tt_roam_node) are equally sized. So it makes sense to have
them allocated from a kmem_cache for each type.

This approach allowed a small wireless router (TP-Link TL-841NDv8; SLUB
allocator) to store 34% more translation table entries compared to the
current implementation.

[1] https://open-mesh.org/projects/batman-adv/wiki/Kmalloc-kmem-cache-tests

Reported-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>

1 files changed, 14 insertions, 2 deletions

diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index f61479b5a99d..ef07e5b34415 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -82,6 +82,12 @@ static void batadv_recv_handler_init(void);
 
 static int __init batadv_init(void)
 {
+	int ret;
+
+	ret = batadv_tt_cache_init();
+	if (ret < 0)
+		return ret;
+
 	INIT_LIST_HEAD(&batadv_hardif_list);
 	batadv_algo_init();
 
@@ -93,9 +99,8 @@ static int __init batadv_init(void)
 	batadv_tp_meter_init();
 
 	batadv_event_workqueue = create_singlethread_workqueue("bat_events");
-
 	if (!batadv_event_workqueue)
-		return -ENOMEM;
+		goto err_create_wq;
 
 	batadv_socket_init();
 	batadv_debugfs_init();
@@ -108,6 +113,11 @@ static int __init batadv_init(void)
 		BATADV_SOURCE_VERSION, BATADV_COMPAT_VERSION);
 
 	return 0;
+
+err_create_wq:
+	batadv_tt_cache_destroy();
+
+	return -ENOMEM;
 }
 
 static void __exit batadv_exit(void)
@@ -123,6 +133,8 @@ static void __exit batadv_exit(void)
 	batadv_event_workqueue = NULL;
 
 	rcu_barrier();
+
+	batadv_tt_cache_destroy();
 }
 
 int batadv_mesh_init(struct net_device *soft_iface)