From: Sven Eckelmann sven@narfation.org
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 --- net/batman-adv/gateway_client.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/net/batman-adv/gateway_client.c b/net/batman-adv/gateway_client.c index bb015862..e1e1f31 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) &&