From 94b059520d6c0cea852dc9a3e9033c6f123df7c1 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Fri, 16 Oct 2009 04:02:20 +0000 Subject: [PATCH] af_packet: Avoid cache line dirtying While doing multiple captures, I found af_packet was dirtying cache line containing its prot_hook. This slow down machines where several cpus are necessary to handle capture traffic, as each prot_hook is traversed for each packet coming in or out the host. This patches moves "struct packet_type prot_hook" to the end of packet_sock, and uses a ____cacheline_aligned_in_smp to make sure this remains shared by all cpus. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/packet/af_packet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index bf3a2954cd4d..dac775e0bc72 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -188,7 +188,6 @@ struct packet_sock { struct packet_ring_buffer tx_ring; int copy_thresh; #endif - struct packet_type prot_hook; spinlock_t bind_lock; struct mutex pg_vec_lock; unsigned int running:1, /* prot_hook is attached*/ @@ -204,6 +203,7 @@ struct packet_sock { unsigned int tp_reserve; unsigned int tp_loss:1; #endif + struct packet_type prot_hook ____cacheline_aligned_in_smp; }; struct packet_skb_cb { -- 2.30.2