From a6501e080c318f8d4467679d17807f42b3a33cd5 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 18 Jan 2008 03:33:26 -0800 Subject: [IPV4] FIB_HASH: Reduce memory needs and speedup lookups Currently, sizeof(struct fib_alias) is 24 or 48 bytes on 32/64 bits arches. Because of SLAB_HWCACHE_ALIGN requirement, these are rounded to 32 and 64 bytes respectively. This patch moves rcu to the end of fib_alias, and conditionally defines it only for CONFIG_IP_FIB_TRIE. We also remove SLAB_HWCACHE_ALIGN requirement for fib_alias and fib_node objects because it is not necessary. (BTW SLUB currently denies it for objects smaller than cache_line_size() / 2, but not SLAB) Finally, sizeof(fib_alias) go back to 16 and 32 bytes. Then, we can embed one fib_alias on each fib_node, to favor locality. Most of the time access to the fib_alias will be free because one cache line contains both the list head (fn_alias) and (one of) the list element. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/ipv4/fib_lookup.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'net/ipv4/fib_lookup.h') diff --git a/net/ipv4/fib_lookup.h b/net/ipv4/fib_lookup.h index 26ee66d78c18..2c1623d2768b 100644 --- a/net/ipv4/fib_lookup.h +++ b/net/ipv4/fib_lookup.h @@ -7,12 +7,14 @@ struct fib_alias { struct list_head fa_list; - struct rcu_head rcu; struct fib_info *fa_info; u8 fa_tos; u8 fa_type; u8 fa_scope; u8 fa_state; +#ifdef CONFIG_IP_FIB_TRIE + struct rcu_head rcu; +#endif }; #define FA_S_ACCESSED 0x01 -- cgit v1.2.3-59-g8ed1b