Subject: Re: panic: m_copydata: m == 0, len 1
To: Jared D. McNeill <>
From: Martin Husemann <>
List: port-alpha
Date: 05/07/2005 00:38:55
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?