From 270acefafeb74ce2fe93d35b75733870bf1e11e7 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Wed, 5 Nov 2008 01:38:06 -0800 Subject: [PATCH] net: sk_free_datagram() should use sk_mem_reclaim_partial() I noticed a contention on udp_memory_allocated on regular UDP applications. While tcp_memory_allocated is seldom used, it appears each incoming UDP frame is currently touching udp_memory_allocated when queued, and when received by application. One possible solution is to use sk_mem_reclaim_partial() instead of sk_mem_reclaim(), so that we keep a small reserve (less than one page) of memory for each UDP socket. We did something very similar on TCP side in commit 9993e7d313e80bdc005d09c7def91903e0068f07 ([TCP]: Do not purge sk_forward_alloc entirely in tcp_delack_timer()) A more complex solution would need to convert prot->memory_allocated to use a percpu_counter with batches of 64 or 128 pages. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/datagram.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/net/core/datagram.c b/net/core/datagram.c index ee631843c2f5..5e2ac0c4b07c 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -209,7 +209,7 @@ struct sk_buff *skb_recv_datagram(struct sock *sk, unsigned flags, void skb_free_datagram(struct sock *sk, struct sk_buff *skb) { kfree_skb(skb); - sk_mem_reclaim(sk); + sk_mem_reclaim_partial(sk); } /** @@ -248,8 +248,7 @@ int skb_kill_datagram(struct sock *sk, struct sk_buff *skb, unsigned int flags) spin_unlock_bh(&sk->sk_receive_queue.lock); } - kfree_skb(skb); - sk_mem_reclaim(sk); + skb_free_datagram(sk, skb); return err; }