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authorSven Eckelmann <sven@narfation.org>2015-06-22 09:13:23 +0200
committerAntonio Quartulli <antonio@meshcoding.com>2015-08-11 18:10:04 +0200
commite071d93eb40c969dc8c578dde5ddd89a30fb01cb (patch)
treef32db816f78240c73b810137f3a8d360955cde2b /net/batman-adv
parent07a51cd3794960548627a27aae68c1446341db32 (diff)
downloadlinux-e071d93eb40c969dc8c578dde5ddd89a30fb01cb.tar.bz2
batman-adv: Replace gw_reselect divisor with simple shift
The gw_factor is divided by BATADV_TQ_LOCAL_WINDOW_SIZE ** 2 * 64. But the rest of the calculation has nothing to do with the tq window size and therefore the calculation is just (tmp_gw_factor / (64 ** 3)). Replace it with a simple shift to avoid a costly 64-bit divide when the max_gw_factor is changed from u32 to u64. This type change is necessary to avoid an overflow bug. Signed-off-by: Sven Eckelmann <sven@narfation.org> Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Diffstat (limited to 'net/batman-adv')
-rw-r--r--net/batman-adv/gateway_client.c6
1 files changed, 1 insertions, 5 deletions
diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c
index bb0158620628..e1e1f317b915 100644
--- a/net/batman-adv/gateway_client.c
+++ b/net/batman-adv/gateway_client.c
@@ -154,14 +154,10 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
struct batadv_neigh_ifinfo *router_ifinfo;
struct batadv_gw_node *gw_node, *curr_gw = NULL;
uint32_t max_gw_factor = 0, tmp_gw_factor = 0;
- uint32_t gw_divisor;
uint8_t max_tq = 0;
uint8_t tq_avg;
struct batadv_orig_node *orig_node;
- gw_divisor = BATADV_TQ_LOCAL_WINDOW_SIZE * BATADV_TQ_LOCAL_WINDOW_SIZE;
- gw_divisor *= 64;
-
rcu_read_lock();
hlist_for_each_entry_rcu(gw_node, &bat_priv->gw.list, list) {
if (gw_node->deleted)
@@ -187,7 +183,7 @@ batadv_gw_get_best_gw_node(struct batadv_priv *bat_priv)
tmp_gw_factor = tq_avg * tq_avg;
tmp_gw_factor *= gw_node->bandwidth_down;
tmp_gw_factor *= 100 * 100;
- tmp_gw_factor /= gw_divisor;
+ tmp_gw_factor >>= 18;
if ((tmp_gw_factor > max_gw_factor) ||
((tmp_gw_factor == max_gw_factor) &&