• Eric Dumazet's avatar
    net: move inet_dport/inet_num in sock_common · ce43b03e
    Eric Dumazet authored
    commit 68835aba (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 in lookups.
    
    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.
    
    IP/TCP early demux needs inet->rx_dst_ifindex and
    TCP needs inet->min_ttl, lets group them together in same cache line.
    
    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. My tests show an improvement
    doing so.
    Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
    Cc: Ben Hutchings <bhutchings@solarflare.com>
    Cc: Joe Perches <joe@perches.com>
    Cc: Ling Ma <ling.ma.program@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    ce43b03e
ipv6.h 8.93 KB