On Mon, 08 Jan 2007 08:57:10 -0800
Ben Greear [off-list ref] wrote:

Jarek Poplawski wrote:

quoted

On Fri, Jan 05, 2007 at 12:33:43PM -0800, Ben Greear wrote:
...
  

quoted

So, I do believe this was the problem we were hitting, and it seems fixed.
    

Congratulations!

But I can see one strange thing in vlan.c:

/* Must be invoked with RCU read lock (no preempt) */
static struct vlan_group *__vlan_find_group(int real_dev_ifindex)
...
 * Must be invoked with RCU read lock (no preempt)
 */
struct net_device *__find_vlan_dev(struct net_device *real_dev,
...

But later in this file no sign of disabling preemption
for these calls and for hlist_add_head_rcu and hlist_del_rcu.

I can't imagine how this works?

Preempt is already disabled on the receive path.

quoted

Perhaps...I didn't RCU-ify VLANs, but I can take a look.

For the record, the soft lockup was using MAC-VLANs, not 802.1Q VLANs, 
so it wouldn't
have been affected by bugs in VLANs one way or the other.

Ben

quoted

Jarek P. 
  

-- 
Stephen Hemminger [off-list ref]