From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH RFC] net: decrease the length of backlog queue
 immediately after it's detached from sk
Date: Fri, 08 Apr 2016 12:53:36 -0400 (EDT)
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From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Fri, 08 Apr 2016 07:44:25 -0700

> On Fri, 2016-04-08 at 19:18 +0800, Yang Yingliang wrote:
> 
>> I expand  tcp_adv_win_scale and tcp_rmem. It has no effect.
> 
> Try :
> 
> echo -2 >/proc/sys/net/ipv4/tcp_adv_win_scale
> 
> And restart your flows.

I'm honestly beginning to suspect a bug in their driver and how they
handle skb->truesize.

Yang, until you show us the driver you are using and how is handles
receive packets, we are largely in the dark about a major component
of this issue and that is entirely unfair to us.