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| author | Eric Dumazet <edumazet@google.com> | 2016-11-18 17:18:03 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-11-21 11:26:59 -0500 |
| commit | d21dbdfe0afb5195607d207f894fe86d5b322d46 (patch) | |
| tree | 2c0e30146d70859144e25cdf665b09750fa6eb99 /net/ipv6/udp.c | |
| parent | ee9d5461c0e88c51f08d0ef7149ce8469a4b4340 (diff) | |
| download | linux-stable-d21dbdfe0afb5195607d207f894fe86d5b322d46.tar.gz linux-stable-d21dbdfe0afb5195607d207f894fe86d5b322d46.tar.bz2 linux-stable-d21dbdfe0afb5195607d207f894fe86d5b322d46.zip | |
udp: avoid one cache line miss in recvmsg()
UDP_SKB_CB(skb)->partial_cov is located at offset 66 in skb,
requesting a cold cache line being read in cpu cache.
We can avoid this cache line miss for UDP sockets,
as partial_cov has a meaning only for UDPLite.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv6/udp.c')
| -rw-r--r-- | net/ipv6/udp.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 4f99417d9b40..8fd4d89380b8 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -363,7 +363,8 @@ try_again: * coverage checksum (UDP-Lite), do it before the copy. */ - if (copied < ulen || UDP_SKB_CB(skb)->partial_cov || peeking) { + if (copied < ulen || peeking || + (is_udplite && UDP_SKB_CB(skb)->partial_cov)) { checksum_valid = !udp_lib_checksum_complete(skb); if (!checksum_valid) goto csum_copy_err; |