Re: TCP transmit performance regression

Eric Dumazet
2012-07-05T08:33:17Z

On Thu, 2012-07-05 at 16:27 +0800, Ming Lei wrote:

> After some investigation, the problem is caused by enabling
> DEBUG_SLAB, so it is not a regression.
>

Strange, unless your machine is a _very_ slow one maybe ?

>
> Looks no improvement. I still don't know why the window size becomes so
> small even in good situation(disabling DEBUG_SLAB), and the small
> window size will cause almost every tcp data packet acked.

You are probably missing the fact that window scaling is enabled.

If you dont post a pcap, I am afraid we cant really help.