diff options
| author | Eric Dumazet <dada1@cosmosbay.com> | 2007-03-05 00:05:44 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@sunset.davemloft.net> | 2007-04-26 05:23:27 (GMT) |
| commit | fa438ccfdfd3f6db02c13b61b21454eb81cd6a13 (patch) | |
| tree | a1759259d7543586185e2fb9db21461147944f18 /include | |
| parent | e317f6f69cb95527799d308a9421b7dc1252989a (diff) | |
| download | linux-fa438ccfdfd3f6db02c13b61b21454eb81cd6a13.tar.xz | |
[NET]: Keep sk_backlog near sk_lock
sk_backlog is a critical field of struct sock. (known famous words)
It is (ab)used in hot paths, in particular in release_sock(), tcp_recvmsg(),
tcp_v4_rcv(), sk_receive_skb().
It really makes sense to place it next to sk_lock, because sk_backlog is only
used after sk_lock locked (and thus memory cache line in L1 cache). This
should reduce cache misses and sk_lock acquisition time.
(In theory, we could only move the head pointer near sk_lock, and leaving tail
far away, because 'tail' is normally not so hot, but keep it simple :) )
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/sock.h | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/include/net/sock.h b/include/net/sock.h index 2c7d60c..a3366c3 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -202,6 +202,15 @@ struct sock { unsigned short sk_type; int sk_rcvbuf; socket_lock_t sk_lock; + /* + * The backlog queue is special, it is always used with + * the per-socket spinlock held and requires low latency + * access. Therefore we special case it's implementation. + */ + struct { + struct sk_buff *head; + struct sk_buff *tail; + } sk_backlog; wait_queue_head_t *sk_sleep; struct dst_entry *sk_dst_cache; struct xfrm_policy *sk_policy[2]; @@ -221,15 +230,6 @@ struct sock { int sk_rcvlowat; unsigned long sk_flags; unsigned long sk_lingertime; - /* - * The backlog queue is special, it is always used with - * the per-socket spinlock held and requires low latency - * access. Therefore we special case it's implementation. - */ - struct { - struct sk_buff *head; - struct sk_buff *tail; - } sk_backlog; struct sk_buff_head sk_error_queue; struct proto *sk_prot_creator; rwlock_t sk_callback_lock; |