RE: Adding qdiscs crashes kernel??

["Leigh Sharpe" <lsharpe@xxxxxxxxxxxxxxxxxxxxxx>]

Oh,

kernel version 2.6.23, since I forgot to mention it.

 

Leigh.

---

From: lartc-bounces@xxxxxxxxxxxxxxx [mailto:lartc-bounces@xxxxxxxxxxxxxxx] On Behalf Of Leigh Sharpe
Sent: Wednesday, 5 December 2007 3:37 PM
To: lartc@xxxxxxxxxxxxxxx
Subject: Adding qdiscs crashes kernel??

Hi all,

 I'm having some problems setting up qdiscs on a bridge.The config looks a little like this:

 

 

ifconfig ifb0 up        # Bring up the IFB for this bridge.

tc qdisc add dev eth2 ingress
tc qdisc add dev eth3 ingress
tc qdisc add dev ifb0 root handle 1:0 cbq bandwidth 100Mbit avpkt 1000 cell 8
# Raw qdiscs on each bridge port
tc qdisc add dev eth2 root handle 1:0 cbq bandwidth 100Mbit avpkt 1000 cell 8
tc qdisc add dev eth3 root handle 1:0 cbq bandwidth 100Mbit avpkt 1000 cell 8

tc filter add dev eth2 parent 1: protocol 0x8100 prio 5 u32 match u16 3000 0x0fff at 0 flowid 1:1 action ipt -j MARK --or-mark 0x01000000 # mark packets for VLAN 3000.
tc filter add dev eth3 parent 1: protocol 0x8100 prio 5 u32 match u16 3000 0x0fff at 0 flowid 1:1 action ipt -j MARK --or-mark 0x01000000 # mark packets for VLAN 3000.

 

tc class add dev eth2 parent 1:0 classid 1:1 cbq bandwidth 100Mbit rate 2000Kbit weight 200Kbit prio 1 allot 1514 cell 8 maxburst 20 avpkt 1000  bounded isolated       # 2000 Kbit rate limit on entry point.
tc class add dev eth3 parent 1:0 classid 1:1 cbq bandwidth 100Mbit rate 2000Kbit weight 200Kbit prio 1 allot 1514 cell 8 maxburst 20 avpkt 1000  bounded isolated       # 2000 Kbit rate limit on entry point.

tc qdisc add dev eth2 parent 1:1 handle 2: cbq bandwidth 100Mbit  avpkt 1000 cell 8
tc qdisc add dev eth3 parent 1:1 handle 2: cbq bandwidth 100Mbit  avpkt 1000 cell 8

tc class add dev eth2 parent 2:0 classid 2:1 cbq bandwidth 100Mbit rate 2000Kbit weight 200Kbit prio 2 allot 1514 cell 8 maxburst 20 avpkt 1000  sharing
tc filter add dev eth2 parent 2:0 protocol 0x8100 prio 2 u32 match u16 3000 0x0fff at 0 flowid 2:1 action ipt -j MARK --or-mark 0x00100000

tc qdisc add dev eth2 parent 2:1 handle 3: cbq bandwidth 100Mbit avpkt 1000 cell 8    

tc filter add dev eth2 parent 3:0 protocol 0x8100 prio 4 u32 match u32 0 0 flowid 3:3                                                   # Traffic class 3 - catchall. Don't MARK further.

 

(There's lot's more, mostly a repeat of the above with different criteria.)

When I first boot the box, and apply the traffic shaping before any traffic flows, all is fine. However, if I apply this same config whilst the bridge is passing lots of traffic, it completely crashes the box. Everything freezes, I don't even get a kernel panic message on the console. Nothing responds and the only way to recover is by a power-cycle.

 

If I take the link down on the ethernet port (with ip link set ethx down), apply the configs, and then bring it back up again, all is OK. Obviously, though, this isn't really acceptable.

 

It always crashes immediately after a 'tc qdisc add...' line, but not always in the same place. Are there any known issues with adding qdiscs whilst traffic is being queued on it?

I've also tried it using HTB instead of CBQ, and I get the same results.

 

Anybody got any other ideas as to what might be going on?

 

Regards,
             Leigh

 

Leigh Sharpe
Network Systems Engineer
Pacific Wireless
Ph +61 3 9584 8966
Mob 0408 009 502

Helpdesk 1300 300 616
email lsharpe@xxxxxxxxxxxxxxxxxxxxxx
web www.pacificwireless.com.au

 

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