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| author | Eric Dumazet <eric.dumazet@gmail.com> | 2010-04-28 14:35:48 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-04-28 14:35:48 -0700 |
| commit | 4b0b72f7dd617b13abd1b04c947e15873e011a24 (patch) | |
| tree | 16fc7bc990fa47cccb62bdb34cb23bd3c26b7a50 /net/core | |
| parent | cfc1fbb079b265bf69d4ceba590a2e2c1a1cde33 (diff) | |
| download | op-kernel-dev-4b0b72f7dd617b13abd1b04c947e15873e011a24.zip op-kernel-dev-4b0b72f7dd617b13abd1b04c947e15873e011a24.tar.gz | |
net: speedup udp receive path
Since commit 95766fff ([UDP]: Add memory accounting.),
each received packet needs one extra sock_lock()/sock_release() pair.
This added latency because of possible backlog handling. Then later,
ticket spinlocks added yet another latency source in case of DDOS.
This patch introduces lock_sock_bh() and unlock_sock_bh()
synchronization primitives, avoiding one atomic operation and backlog
processing.
skb_free_datagram_locked() uses them instead of full blown
lock_sock()/release_sock(). skb is orphaned inside locked section for
proper socket memory reclaim, and finally freed outside of it.
UDP receive path now take the socket spinlock only once.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/datagram.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c index 5574a5dd..95b851f 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -229,9 +229,13 @@ EXPORT_SYMBOL(skb_free_datagram); void skb_free_datagram_locked(struct sock *sk, struct sk_buff *skb) { - lock_sock(sk); - skb_free_datagram(sk, skb); - release_sock(sk); + lock_sock_bh(sk); + skb_orphan(skb); + sk_mem_reclaim_partial(sk); + unlock_sock_bh(sk); + + /* skb is now orphaned, might be freed outside of locked section */ + consume_skb(skb); } EXPORT_SYMBOL(skb_free_datagram_locked); |
