NICs locking up, "*tcp_sc_h"

[Robert Watson]

On Sun, 15 Mar 2009, Nick Withers wrote:

>> I'll need to think a bit about a proper fix for this, but you'll find the 
>> problem likely goes away if you eliminate all uid/gid/jail rules from your 
>> firewall.  You could also tweak the syncache logic not to use a retransmit 
>> timer, which might slightly extend the time it takes for systems to connect 
>> to your host in the presence of packet loss, but would eliminate this 
>> transmission path entirely.  We'll need a real and more general fix, 
>> however, to commit, and I'll look and see what I can come up with.
>
> Brilliant, thanks very much. I'll work without uid rules for the time being, 
> then.

Could I ask you to file a PR on this problem, btw, with the two traces I 
singled out as interesting included, then forward me the PR receipt?  That 
will make the problem easier to keep track of.

We're currently pondering ways to fix the problem that don't disturb the 
stability of the ABI, and may have a workaround patch available shortly that's 
appropriate for MFC.

Robert N M Watson
Computer Laboratory
University of Cambridge