Commit 8a0f62fd authored by Eric Dumazet's avatar Eric Dumazet Committed by Jakub Kicinski
Browse files

ipv4: remove fib_devindex_hashfn() 



fib_devindex_hashfn() converts a 32bit ifindex value to a 8bit hash.

It makes no sense doing this from fib_info_hashfn() and
fib_find_info_nh().

It is better to keep as many bits as possible to let
fib_info_hashfn_result() have better spread.

Only fib_info_devhash_bucket() needs to make this operation,
we can 'inline' trivial fib_devindex_hashfn() in it.

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Reviewed-by: default avatarKuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: default avatarDavid Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20241004134720.579244-2-edumazet@google.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 1405981b

net/ipv4/fib_semantics.c

+4 −9
Original line number Diff line number Diff line
@@ -322,17 +322,12 @@ static inline int nh_comp(struct fib_info *fi, struct fib_info *ofi) 
	return 0;

}



static inline unsigned int fib_devindex_hashfn(unsigned int val)

{

	return hash_32(val, DEVINDEX_HASHBITS);

}



static struct hlist_head *

fib_info_devhash_bucket(const struct net_device *dev)

{

	u32 val = net_hash_mix(dev_net(dev)) ^ dev->ifindex;



	return &fib_info_devhash[fib_devindex_hashfn(val)];

	return &fib_info_devhash[hash_32(val, DEVINDEX_HASHBITS)];

}



static unsigned int fib_info_hashfn_1(int init_val, u8 protocol, u8 scope,
@@ -362,10 +357,10 @@ static inline unsigned int fib_info_hashfn(struct fib_info *fi) 
				fi->fib_priority);



	if (fi->nh) {

		val ^= fib_devindex_hashfn(fi->nh->id);

		val ^= fi->nh->id;

	} else {

		for_nexthops(fi) {

			val ^= fib_devindex_hashfn(nh->fib_nh_oif);

			val ^= nh->fib_nh_oif;

		} endfor_nexthops(fi)

	}
@@ -380,7 +375,7 @@ static struct fib_info *fib_find_info_nh(struct net *net, 
	struct fib_info *fi;

	unsigned int hash;



	hash = fib_info_hashfn_1(fib_devindex_hashfn(cfg->fc_nh_id),

	hash = fib_info_hashfn_1(cfg->fc_nh_id,

				 cfg->fc_protocol, cfg->fc_scope,

				 (__force u32)cfg->fc_prefsrc,

				 cfg->fc_priority);