Re: [PATCH v2 net-next] net: move inet_dport/inet_num in sock_common

David Miller
2012-11-28T16:48:38Z

From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 28 Nov 2012 04:56:18 -0800

> From: Eric Dumazet <edumazet@google.com>
>
> commit 68835aba4d9b (net: optimize INET input path further)
> moved some fields used for tcp/udp sockets lookup in the first cache
> line of struct sock_common.
>
> This patch moves inet_dport/inet_num as well, filling a 32bit hole
> on 64 bit arches and reducing number of cache line misses.
>
> Also change INET_MATCH()/INET_TW_MATCH() to perform the ports match
> before addresses match, as this check is more discriminant.
>
> Remove the hash check from MATCH() macros because we dont need to
> re validate the hash value after taking a refcount on socket, and
> use likely/unlikely compiler hints, as the sk_hash/hash check
> makes the following conditional tests 100% predicted by cpu.
>
> Introduce skc_addrpair/skc_portpair pair values to better
> document the alignment requirements of the port/addr pairs
> used in the various MATCH() macros, and remove some casts.
>
> The namespace check can also be done at last.
>
> This slightly improves TCP/UDP lookup times.
>
> With help from Ben Hutchings & Joe Perches.
>
> Idea of this patch came after Ling Ma proposal to move skc_hash
> to the beginning of struct sock_common, and should allow him
> to submit a final version of his patch.
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>

I like this a lot, applied, thanks Eric!