Subject: Re: panic: m_copydata: m == 0, len 1
To: Martin Husemann <>
From: Jared D. McNeill <>
List: port-alpha
Date: 05/06/2005 20:14:46
On 6-May-05, at 7:38 PM, Martin Husemann wrote:

> On Wed, May 04, 2005 at 07:23:00PM -0300, Jared D. McNeill wrote:
>> I'm pretty sure this is related to the new TCP SACK code. I've worked
>> around the panic on my two affected machines (one alpha, one  
>> sparc) by
>> setting:
>>   sysctl -w net.inet.tcp.sack=0
>>   sysctl -w net.inet6.tcp6.sack=0
> There have been multiple reports of this (and ACKs that this  
> workaround
> helps) - but there seems to be no PR for it yet.
> Jared, could you please file one?

Done. Not much detail in it though as I haven't dug into the issue  
(not really my work area). PR# is kern/30160.