path: root/net/ipv4/inet_hashtables.c
diff options
authorEric Dumazet <edumazet@google.com>2015-10-08 19:33:21 -0700
committerDavid S. Miller <davem@davemloft.net>2015-10-12 19:28:20 -0700
commit70da268b569d32a9fddeea85dc18043de9d89f89 (patch)
tree6c698924212dcbfbb155e794f6089d2226889f0f /net/ipv4/inet_hashtables.c
parentpacket: support per-packet fwmark for af_packet sendmsg (diff)
net: SO_INCOMING_CPU setsockopt() support
SO_INCOMING_CPU as added in commit 2c8c56e15df3 was a getsockopt() command to fetch incoming cpu handling a particular TCP flow after accept() This commits adds setsockopt() support and extends SO_REUSEPORT selection logic : If a TCP listener or UDP socket has this option set, a packet is delivered to this socket only if CPU handling the packet matches the specified one. This allows to build very efficient TCP servers, using one listener per RX queue, as the associated TCP listener should only accept flows handled in softirq by the same cpu. This provides optimal NUMA behavior and keep cpu caches hot. Note that __inet_lookup_listener() still has to iterate over the list of all listeners. Following patch puts sk_refcnt in a different cache line to let this iteration hit only shared and read mostly cache lines. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index bed8886a4b6c..08643a3616af 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -185,6 +185,8 @@ static inline int compute_score(struct sock *sk, struct net *net,
return -1;
score += 4;
+ if (sk->sk_incoming_cpu == raw_smp_processor_id())
+ score++;
return score;