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| author | Sven Eckelmann <sven@narfation.org> | 2015-06-22 09:13:23 +0200 |
|---|---|---|
| committer | Antonio Quartulli <antonio@meshcoding.com> | 2015-08-11 18:10:04 +0200 |
| commit | e071d93eb40c969dc8c578dde5ddd89a30fb01cb (patch) | |
| tree | f32db816f78240c73b810137f3a8d360955cde2b /net/batman-adv | |
| parent | 07a51cd3794960548627a27aae68c1446341db32 (diff) | |
| download | lwn-e071d93eb40c969dc8c578dde5ddd89a30fb01cb.tar.gz lwn-e071d93eb40c969dc8c578dde5ddd89a30fb01cb.zip | |
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.c | 6 |
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) && |