mac80211: Speedup ieee80211_remove_interfaces()

Speedup ieee80211_remove_interfaces() by factorizing synchronize_rcu() calls

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Reviewed-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 5 insertions, 9 deletions

diff --git a/net/mac80211/iface.c b/net/mac80211/iface.c
index 1bf12a26b45e..80c16f6e2af6 100644
--- a/net/mac80211/iface.c
+++ b/net/mac80211/iface.c
@@ -860,22 +860,18 @@ void ieee80211_if_remove(struct ieee80211_sub_if_data *sdata)
 void ieee80211_remove_interfaces(struct ieee80211_local *local)
 {
         struct ieee80211_sub_if_data *sdata, *tmp;
+        LIST_HEAD(unreg_list);
 
         ASSERT_RTNL();
 
+        mutex_lock(&local->iflist_mtx);
         list_for_each_entry_safe(sdata, tmp, &local->interfaces, list) {
-                /*
-                 * we cannot hold the iflist_mtx across unregister_netdevice,
-                 * but we only need to hold it for list modifications to lock
-                 * out readers since we're under the RTNL here as all other
-                 * writers.
-                 */
-                mutex_lock(&local->iflist_mtx);
                 list_del(&sdata->list);
-                mutex_unlock(&local->iflist_mtx);
 
-                unregister_netdevice(sdata->dev);
+                unregister_netdevice_queue(sdata->dev, &unreg_list);
         }
+        mutex_unlock(&local->iflist_mtx);
+        unregister_netdevice_many(&unreg_list);
 }
 
 static u32 ieee80211_idle_off(struct ieee80211_local *local,