| Message ID | 4AD87CEC.4020407@gmail.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Eric Dumazet <eric.dumazet@gmail.com> Date: Fri, 16 Oct 2009 16:02:20 +0200 > 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 <eric.dumazet@gmail.com> Applied. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index bf3a295..dac775e 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 {
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 <eric.dumazet@gmail.com> --- -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html