kern/154428: xn0 network interface and PF - Massive performance drop

[Colin Percival]

On 02/12/11 20:18, Alex wrote:
> Fixed by net.inet.tcp.tso: 1 -> 0
> 
> but why?? found this by trial an error.  setting net.inet.tcp.tso to 0
> with pf enabled gives good performance, if i set it to 1, speeds plumet
> to below dialup!

There have been problems with Xen and TSO in the past relating to how much
data gets handed off to the hypervisor at once... why this would cause issues
only with PF, I have no idea, though.

-- 
Colin Percival
Security Officer, FreeBSD | freebsd.org | The power to serve
Founder / author, Tarsnap | tarsnap.com | Online backups for the truly paranoid