linux.git/net/ipv4/ip_gre.c, branch v2.6.37

ip_gre: fix fallback tunnel setup

2010-10-30T23:21:28+00:00

Before making the fallback tunnel visible to lookups, we should make
sure it is completely setup, once ipgre_tunnel_init() had been called
and tstats per_cpu pointer allocated.

move rcu_assign_pointer(ign->tunnels_wc[0], tunnel); from
ipgre_fb_tunnel_init() to ipgre_init_net()

Based on a patch from Pavel Emelyanov

Reported-by: Pavel Emelyanov 
Signed-off-by: Eric Dumazet 
Acked-by: Pavel Emelyanov 
Signed-off-by: David S. Miller

tunnels: Fix tunnels change rcu protection

2010-10-27T21:20:08+00:00

After making rcu protection for tunnels (ipip, gre, sit and ip6) a bug
was introduced into the SIOCCHGTUNNEL code.

The tunnel is first unlinked, then addresses change, then it is linked
back probably into another bucket. But while changing the parms, the
hash table is unlocked to readers and they can lookup the improper tunnel.

Respective commits are b7285b79 (ipip: get rid of ipip_lock), 1507850b
(gre: get rid of ipgre_lock), 3a43be3c (sit: get rid of ipip6_lock) and
94767632 (ip6tnl: get rid of ip6_tnl_lock).

The quick fix is to wait for quiescent state to pass after unlinking,
but if it is inappropriate I can invent something better, just let me
know.

Signed-off-by: Pavel Emelyanov 
Acked-by: Eric Dumazet 
Signed-off-by: David S. Miller

inet: RCU changes in inetdev_by_index()

2010-10-19T10:50:48+00:00

Convert inetdev_by_index() to not increment in_dev refcount.

Callers hold RCU or RTNL, and should not decrement in_dev refcount.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: add a core netdev->rx_dropped counter

2010-10-05T21:47:55+00:00

In various situations, a device provides a packet to our stack and we
drop it before it enters protocol stack :
- softnet backlog full (accounted in /proc/net/softnet_stat)
- bad vlan tag (not accounted)
- unknown/unregistered protocol (not accounted)

We can handle a per-device counter of such dropped frames at core level,
and automatically adds it to the device provided stats (rx_dropped), so
that standard tools can be used (ifconfig, ip link, cat /proc/net/dev)

This is a generalization of commit 8990f468a (net: rx_dropped
accounting), thus reverting it.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

ip_gre: comments change

2010-09-30T06:35:10+00:00

HARD_TX_LOCK no longer protects tunnels from dead loops,
but xmit_recursion percpu counter.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

ip_gre: lockless xmit

2010-09-29T20:25:38+00:00

GRE tunnels can benefit from lockless xmits, using NETIF_F_LLTX

Note: If tunnels are created with the "oseq" option, LLTX is not
enabled :

Even using an atomic_t o_seq, we would increase chance for packets being
out of order at receiver.

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

Before patch :
real	3m0.094s
user	0m9.365s
sys	47m50.103s

After patch:
real	0m29.756s
user	0m11.097s
sys	7m33.012s

Last problem to solve is the contention on dst :

38660.00 21.4% __ip_route_output_key          vmlinux
20786.00 11.5% dst_release                    vmlinux
14191.00  7.8% __xfrm_lookup                  vmlinux
12410.00  6.9% ip_finish_output               vmlinux
 4540.00  2.5% ip_push_pending_frames         vmlinux
 4427.00  2.4% ip_append_data                 vmlinux
 4265.00  2.4% __alloc_skb                    vmlinux
 4140.00  2.3% __ip_local_out                 vmlinux
 3991.00  2.2% dev_queue_xmit                 vmlinux

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

ip_gre: percpu stats accounting

2010-09-28T04:30:43+00:00

Le lundi 27 septembre 2010 à 14:29 +0100, Ben Hutchings a écrit :

> > diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
> > index 5d6ddcb..de39b22 100644
> > --- a/net/ipv4/ip_gre.c
> > +++ b/net/ipv4/ip_gre.c
> [...]
> > @@ -377,7 +405,7 @@ static struct ip_tunnel *ipgre_tunnel_locate(struct net *net,
> >  	if (parms->name[0])
> >  		strlcpy(name, parms->name, IFNAMSIZ);
> >  	else
> > -		sprintf(name, "gre%%d");
> > +		strcpy(name, "gre%d");
> >
> >  	dev = alloc_netdev(sizeof(*t), name, ipgre_tunnel_setup);
> >  	if (!dev)
> [...]
>
> This is a valid fix, but doesn't belong in this patch!
>

Sorry ? It was not a fix, but at most a cleanup ;)

Anyway I forgot the gretap case...

[PATCH 2/4 v2] ip_gre: percpu stats accounting

Maintain per_cpu tx_bytes, tx_packets, rx_bytes, rx_packets.

Other seldom used fields are kept in netdev->stats structure, possibly
unsafe.

This is a preliminary work to support lockless transmit path, and
correct RX stats, that are already unsafe.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6

2010-09-27T08:03:03+00:00

Conflicts:
	drivers/net/qlcnic/qlcnic_init.c
	net/ipv4/ip_output.c

net: return operator cleanup

2010-09-23T21:33:39+00:00

Change "return (EXPR);" to "return EXPR;"

return is not a function, parentheses are not required.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: rx_dropped accounting

2010-09-20T17:08:58+00:00

Under load, netif_rx() can drop incoming packets but administrators dont
have a chance to spot which device needs some tuning (RPS activation for
example)

This patch adds rx_dropped accounting in vlans and tunnels.

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller