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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 | |
| parent | cfc1fbb079b265bf69d4ceba590a2e2c1a1cde33 (diff) | |
| download | linux-stable-4b0b72f7dd617b13abd1b04c947e15873e011a24.tar.gz linux-stable-4b0b72f7dd617b13abd1b04c947e15873e011a24.tar.bz2 linux-stable-4b0b72f7dd617b13abd1b04c947e15873e011a24.zip | |
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')
| -rw-r--r-- | net/core/datagram.c | 10 | ||||
| -rw-r--r-- | net/ipv4/udp.c | 12 | ||||
| -rw-r--r-- | net/ipv6/udp.c | 4 |
3 files changed, 15 insertions, 11 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c index 5574a5ddf908..95b851f3d713 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); diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 63eb56b2d873..1f86965ba7d7 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1062,10 +1062,10 @@ static unsigned int first_packet_length(struct sock *sk) spin_unlock_bh(&rcvq->lock); if (!skb_queue_empty(&list_kill)) { - lock_sock(sk); + lock_sock_bh(sk); __skb_queue_purge(&list_kill); sk_mem_reclaim_partial(sk); - release_sock(sk); + unlock_sock_bh(sk); } return res; } @@ -1196,10 +1196,10 @@ out: return err; csum_copy_err: - lock_sock(sk); + lock_sock_bh(sk); if (!skb_kill_datagram(sk, skb, flags)) UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); - release_sock(sk); + unlock_sock_bh(sk); if (noblock) return -EAGAIN; @@ -1624,9 +1624,9 @@ int udp_rcv(struct sk_buff *skb) void udp_destroy_sock(struct sock *sk) { - lock_sock(sk); + lock_sock_bh(sk); udp_flush_pending_frames(sk); - release_sock(sk); + unlock_sock_bh(sk); } /* diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 3ead20ad9d07..91c60f0090a4 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -424,7 +424,7 @@ out: return err; csum_copy_err: - lock_sock(sk); + lock_sock_bh(sk); if (!skb_kill_datagram(sk, skb, flags)) { if (is_udp4) UDP_INC_STATS_USER(sock_net(sk), @@ -433,7 +433,7 @@ csum_copy_err: UDP6_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, is_udplite); } - release_sock(sk); + unlock_sock_bh(sk); if (flags & MSG_DONTWAIT) return -EAGAIN; |