Re: TSO prevents cwnd growth on 2.6 kernels

["David S. Miller" <davem@xxxxxxxxxxxxx>]

On Fri, 25 Mar 2005 12:18:04 -0600
"Scott M. Ferris" <sferris@xxxxxxx> wrote:

> TSO still has problems in 2.6.12-rc1. 

We know it's busted.  I haven't gotten to fixing this stuff
up yet.

> tcp_write_xmit() really needs to be willing to increase
> tcp_packets_in_flight() high enough that tcp_ack() will allow the
> congestion window to grow, even when TSO is being used, otherwise
> there may be a dramatic reduction in the cwnd growth rate.

Are you suggesting to let it go past tp->snd_cwnd?  We can't
ever do that.  tp->snd_cwnd is a hard limit on the number
of frames we may have outstanding on the network at one time,
TSO or not.