Message-ID: <1423053531.907.115.camel@edumazet-glaptop2.roam.corp.google.com> (sfid-20150204_133900_363265_266C57CF)
Subject: Re: Throughput regression with `tcp: refine TSO autosizing`
From: Eric Dumazet <eric.dumazet@gmail.com>
To: Michal Kazior <michal.kazior@tieto.com>
Cc: linux-wireless <linux-wireless@vger.kernel.org>,
	Network Development <netdev@vger.kernel.org>,
	eyalpe@dev.mellanox.co.il
Date: Wed, 04 Feb 2015 04:38:51 -0800
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On Wed, 2015-02-04 at 13:22 +0100, Michal Kazior wrote:
> On 4 February 2015 at 12:57, Eric Dumazet <eric.dumazet@gmail.com> wrote:

> 
> > To disable gso you would have to use :
> >
> > ethtool -K wlan1 gso off
> 
> Oh, thanks! This works. However I can't turn it on:
> 
> ; ethtool -K wlan1 gso on
> Could not change any device features
> 
> ..so I guess it makes no sense to re-run tests because:
> 
> ; ethtool -k wlan1 | grep generic
>         tx-checksum-ip-generic: on [fixed]
> generic-segmentation-offload: off [requested on]
> generic-receive-offload: on
> 
> And this seems to never change.

GSO requires SG (Scatter Gather)

Are you sure this hardware has no SG support ?