Re: Re: Re: Re: limited network bandwidth with 3.2.x kernels

Neal Cardwell
2012-02-17T16:41:05Z

On Thu, Feb 16, 2012 at 5:35 PM, Eric Dumazet <eric.dumazet@gmail.com> wrote:
> An incoming skb is considered as "good citizen" in term of memory usage
> if its truesize is no more than
> len + len/4   (if adv_win_scale == 2)
>
> That was true when truesize was 1500+NET_SKB_PAD+sizeof(sk_buff),
> but not true anymore when truesize is 2048+sizeof(sk_buff), or even more
> when its 4096+sizeof(sk_buff)
>
> So receiver doesnt increase rcv_ssthresh and cannot open its window.
>
> tcp_grow_window() should be tweaked to :
>
> 1) Relax the requirements
> 2) Allow bigger increase in case of super packets (LRO/GRO)

That sounds great. Is this something you're planning on tackling?

neal