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author | Eric Dumazet <edumazet@google.com> | 2015-10-02 11:43:32 -0700 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2015-10-03 04:32:41 -0700 |
commit | 079096f103faca2dd87342cca6f23d4b34da8871 (patch) | |
tree | fa3fb0fdc064f1611c464384e70a7a402179808f /net/ipv4/syncookies.c | |
parent | 2feda34192a379f8b35a7c6c5826b2f23e884f32 (diff) | |
download | linux-079096f103faca2dd87342cca6f23d4b34da8871.tar.gz linux-079096f103faca2dd87342cca6f23d4b34da8871.tar.bz2 linux-079096f103faca2dd87342cca6f23d4b34da8871.zip |
tcp/dccp: install syn_recv requests into ehash table
In this patch, we insert request sockets into TCP/DCCP
regular ehash table (where ESTABLISHED and TIMEWAIT sockets
are) instead of using the per listener hash table.
ACK packets find SYN_RECV pseudo sockets without having
to find and lock the listener.
In nominal conditions, this halves pressure on listener lock.
Note that this will allow for SO_REUSEPORT refinements,
so that we can select a listener using cpu/numa affinities instead
of the prior 'consistent hash', since only SYN packets will
apply this selection logic.
We will shrink listen_sock in the following patch to ease
code review.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Ying Cai <ycai@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/syncookies.c')
-rw-r--r-- | net/ipv4/syncookies.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c index 6b97b5f6457c..729ceb5f63c6 100644 --- a/net/ipv4/syncookies.c +++ b/net/ipv4/syncookies.c @@ -284,6 +284,10 @@ bool cookie_ecn_ok(const struct tcp_options_received *tcp_opt, } EXPORT_SYMBOL(cookie_ecn_ok); +/* On input, sk is a listener. + * Output is listener if incoming packet would not create a child + * NULL if memory could not be allocated. + */ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb) { struct ip_options *opt = &TCP_SKB_CB(skb)->header.h4.opt; |