neigh: new unresolved queue limits

Le mercredi 09 novembre 2011 à 16:21 -0500, David Miller a écrit :
> From: David Miller <davem@davemloft.net>
> Date: Wed, 09 Nov 2011 16:16:44 -0500 (EST)
>
> > From: Eric Dumazet <eric.dumazet@gmail.com>
> > Date: Wed, 09 Nov 2011 12:14:09 +0100
> >
> >> unres_qlen is the number of frames we are able to queue per unresolved
> >> neighbour. Its default value (3) was never changed and is responsible
> >> for strange drops, especially if IP fragments are used, or multiple
> >> sessions start in parallel. Even a single tcp flow can hit this limit.
> >  ...
> >
> > Ok, I've applied this, let's see what happens :-)
>
> Early answer, build fails.
>
> Please test build this patch with DECNET enabled and resubmit.  The
> decnet neigh layer still refers to the removed ->queue_len member.
>
> Thanks.

Ouch, this was fixed on one machine yesterday, but not the other one I
used this morning, sorry.

[PATCH V5 net-next] neigh: new unresolved queue limits

unres_qlen is the number of frames we are able to queue per unresolved
neighbour. Its default value (3) was never changed and is responsible
for strange drops, especially if IP fragments are used, or multiple
sessions start in parallel. Even a single tcp flow can hit this limit.

$ arp -d 192.168.20.108 ; ping -c 2 -s 8000 192.168.20.108
PING 192.168.20.108 (192.168.20.108) 8000(8028) bytes of data.
8008 bytes from 192.168.20.108: icmp_seq=2 ttl=64 time=0.322 ms

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 1 deletions

diff --git a/include/net/neighbour.h b/include/net/neighbour.h
index 2720884287c3..7ae5acff96e9 100644
--- a/include/net/neighbour.h
+++ b/include/net/neighbour.h
@@ -59,7 +59,7 @@ struct neigh_parms {
         int     reachable_time;
         int     delay_probe_time;
 
-        int     queue_len;
+        int     queue_len_bytes;
         int     ucast_probes;
         int     app_probes;
         int     mcast_probes;
@@ -99,6 +99,7 @@ struct neighbour {
         rwlock_t                lock;
         atomic_t                refcnt;
         struct sk_buff_head     arp_queue;
+        unsigned int            arp_queue_len_bytes;
         struct timer_list       timer;
         unsigned long           used;
         atomic_t                probes;