Patchwork [net-next-2.6] ipip: enable lockless xmits

login
register
mail settings
Submitter Eric Dumazet
Date Sept. 28, 2010, 10:17 a.m.
Message ID <1285669037.3154.14.camel@edumazet-laptop>
Download mbox | patch
Permalink /patch/65953/
State Accepted
Delegated to: David Miller
Headers show

Comments

Eric Dumazet - Sept. 28, 2010, 10:17 a.m.
IPIP tunnels can benefit from lockless xmits, using NETIF_F_LLTX


Bench on a 16 cpus machine (dual E5540 cpus), 16 threads sending
10000000 UDP frames via one ipip tunnel (size:200 bytes per frame)

Before patch : 
real	2m53.321s
user	0m10.277s
sys	46m0.597s


After patch:
real	0m32.063s
user	0m9.237s
sys	8m16.255s


Last problem to solve is the contention on dst :

16118.00 28.3% __ip_route_output_key         vmlinux
 6135.00 10.8% dst_release                   vmlinux
 3220.00  5.6% ip_finish_output              vmlinux
 2149.00  3.8% ip_route_output_flow          vmlinux
 1575.00  2.8% ip_append_data                vmlinux
 1481.00  2.6% ip_push_pending_frames        vmlinux
 1349.00  2.4% __xfrm_lookup                 vmlinux
 1216.00  2.1% csum_partial_copy_generic     vmlinux
 1208.00  2.1% udp_sendmsg                   vmlinux


Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
---
 net/ipv4/ipip.c |    1 +
 1 files changed, 1 insertion(+)



--
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
David Miller - Sept. 29, 2010, 8:27 p.m.
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Tue, 28 Sep 2010 12:17:17 +0200

> IPIP tunnels can benefit from lockless xmits, using NETIF_F_LLTX
 ...
> 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

Patch

diff --git a/net/ipv4/ipip.c b/net/ipv4/ipip.c
index 12b6fde..6ad46c2 100644
--- a/net/ipv4/ipip.c
+++ b/net/ipv4/ipip.c
@@ -767,6 +767,7 @@  static void ipip_tunnel_setup(struct net_device *dev)
 	dev->iflink		= 0;
 	dev->addr_len		= 4;
 	dev->features		|= NETIF_F_NETNS_LOCAL;
+	dev->features		|= NETIF_F_LLTX;
 	dev->priv_flags		&= ~IFF_XMIT_DST_RELEASE;
 }