alistair23-linux/net/ipv4/fib_lookup.h
Eric Dumazet a6501e080c [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 <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-01-28 15:02:46 -08:00

54 lines
1.5 KiB
C

#ifndef _FIB_LOOKUP_H
#define _FIB_LOOKUP_H
#include <linux/types.h>
#include <linux/list.h>
#include <net/ip_fib.h>
struct fib_alias {
struct list_head fa_list;
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
/* Exported by fib_semantics.c */
extern int fib_semantic_match(struct list_head *head,
const struct flowi *flp,
struct fib_result *res, __be32 zone, __be32 mask,
int prefixlen);
extern void fib_release_info(struct fib_info *);
extern struct fib_info *fib_create_info(struct fib_config *cfg);
extern int fib_nh_match(struct fib_config *cfg, struct fib_info *fi);
extern int fib_dump_info(struct sk_buff *skb, u32 pid, u32 seq, int event,
u32 tb_id, u8 type, u8 scope, __be32 dst,
int dst_len, u8 tos, struct fib_info *fi,
unsigned int);
extern void rtmsg_fib(int event, __be32 key, struct fib_alias *fa,
int dst_len, u32 tb_id, struct nl_info *info,
unsigned int nlm_flags);
extern struct fib_alias *fib_find_alias(struct list_head *fah,
u8 tos, u32 prio);
extern int fib_detect_death(struct fib_info *fi, int order,
struct fib_info **last_resort,
int *last_idx, int dflt);
static inline void fib_result_assign(struct fib_result *res,
struct fib_info *fi)
{
if (res->fi != NULL)
fib_info_put(res->fi);
res->fi = fi;
if (fi != NULL)
atomic_inc(&fi->fib_clntref);
}
#endif /* _FIB_LOOKUP_H */