From e9897071350bd9d94a56b5b6f79c85b1a98fc7e7 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 7 Jun 2013 08:48:57 -0700 Subject: igmp: hash a hash table to speedup ip_check_mc_rcu() After IP route cache removal, multicast applications using a lot of multicast addresses hit a O(N) behavior in ip_check_mc_rcu() Add a per in_device hash table to get faster lookup. This hash table is created only if the number of items in mc_list is above 4. Reported-by: Shawn Bohrer Signed-off-by: Eric Dumazet Tested-by: Shawn Bohrer Reviewed-by: Cong Wang Signed-off-by: David S. Miller --- include/linux/igmp.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux/igmp.h') diff --git a/include/linux/igmp.h b/include/linux/igmp.h index 7f2bf1518480..e3362b5f13e8 100644 --- a/include/linux/igmp.h +++ b/include/linux/igmp.h @@ -84,6 +84,7 @@ struct ip_mc_list { struct ip_mc_list *next; struct ip_mc_list __rcu *next_rcu; }; + struct ip_mc_list __rcu *next_hash; struct timer_list timer; int users; atomic_t refcnt; -- cgit v1.2.3