From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Fri, 16 Oct 2009 04:02:20 +0000 (+0000)
Subject: af_packet: Avoid cache line dirtying
X-Git-Tag: v2.6.33-rc1~388^2~753
X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=94b059520d6c0cea852dc9a3e9033c6f123df7c1;p=pandora-kernel.git

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 <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

Reading git-diff-tree failed