Re: skge- "soft lockup on CPU#0" with mtu=9000 (2.6.20.1 + web100 patch)

[Jay Vosburgh <fubar@us.ibm.com>]

Chris Stromsoe <cbs@cts.ucla.edu> wrote:

>It's active-backup.  Testing with the same setup and e100 works fine. I've
>done a few tests without the bonding module, using the dual-port
>separately.

	Somebody else a couple of weeks ago was having similar issues
running bonding with skge (in 802.3ad mode, in his case) that also
vanished with different hardware.  I don't have any skge hardware, so I
can't test it here.  His problem was a failure in 802.3ad negotiation,
not a system lockup, though.

	If you're running active-backup and not using the ARP monitor
(arp_interval), then I'm not aware of any possible locking problems in
bonding for the kernel version you reference (2.6.20.1).

>1) ip link set mtu 9000 eth2  <-- eth2 is no longer responsive
>   ip link set mtu 1500 eth2  <-- eth2 remains unresponsive
>
>2) ifup eth2
>   ifdown eth2
>
>   perl -pi -e 's/eth2/eth3/' /etc/network/interfaces
>
>   ifup eth3   <--  locks up here

	This would seem to suggest a problem with skge itself, although
there might be some other interaction with bonding that causes the
problems for that case.

	-J

---
	-Jay Vosburgh, IBM Linux Technology Center, fubar@us.ibm.com