From 2dc41cff7545d55c6294525c811594576f8e119c Mon Sep 17 00:00:00 2001 From: David Held Date: Tue, 15 Jul 2014 23:28:32 -0400 Subject: udp: Use hash2 for long hash1 chains in __udp*_lib_mcast_deliver. Many multicast sources can have the same port which can result in a very large list when hashing by port only. Hash by address and port instead if this is the case. This makes multicast more similar to unicast. On a 24-core machine receiving from 500 multicast sockets on the same port, before this patch 80% of system CPU was used up by spin locking and only ~25% of packets were successfully delivered. With this patch, all packets are delivered and kernel overhead is ~8% system CPU on spinlocks. Signed-off-by: David Held Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- include/net/sock.h | 14 ++++++++++++++ 1 file changed, 14 insertions(+) (limited to 'include/net/sock.h') diff --git a/include/net/sock.h b/include/net/sock.h index 29e48a6d1ded..28f734601b50 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -660,6 +660,20 @@ static inline void sk_add_bind_node(struct sock *sk, #define sk_for_each_bound(__sk, list) \ hlist_for_each_entry(__sk, list, sk_bind_node) +/** + * sk_nulls_for_each_entry_offset - iterate over a list at a given struct offset + * @tpos: the type * to use as a loop cursor. + * @pos: the &struct hlist_node to use as a loop cursor. + * @head: the head for your list. + * @offset: offset of hlist_node within the struct. + * + */ +#define sk_nulls_for_each_entry_offset(tpos, pos, head, offset) \ + for (pos = (head)->first; \ + (!is_a_nulls(pos)) && \ + ({ tpos = (typeof(*tpos) *)((void *)pos - offset); 1;}); \ + pos = pos->next) + static inline struct user_namespace *sk_user_ns(struct sock *sk) { /* Careful only use this in a context where these parameters -- cgit v1.2.3