From: Dimitris Michailidis <dm@chelsio•com>
To: Ben Hutchings <bhutchings@solarflare•com>
Cc: Stephen Hemminger <shemminger@vyatta•com>,
David Miller <davem@davemloft•net>,
Olof Johansson <olof@lixom•net>, Divy Le Ray <divy@chelsio•com>,
netdev@vger•kernel.org
Subject: Re: Misuse of LRO, how widespread
Date: Mon, 06 Dec 2010 15:36:38 -0800 [thread overview]
Message-ID: <4CFD7386.5030906@chelsio.com> (raw)
In-Reply-To: <1291677755.5405.29.camel@bwh-desktop>
Ben Hutchings wrote:
> On Mon, 2010-12-06 at 15:05 -0800, Dimitris Michailidis wrote:
>> Stephen Hemminger wrote:
>>> On Mon, 06 Dec 2010 13:15:42 -0800
>>> Dimitris Michailidis <dm@chelsio•com> wrote:
>>>
>>>> Stephen Hemminger wrote:
>>>>> I inspected all drivers in net-next to see which drivers are using
>>>>> LRO and which ones are broken. Most concerning is that Chelsio
>>>>> and Solarflare drivers ignore ETH_FLAG_LRO.
>>>>>
>>>>> The ones that are using LRO but allow disabling it:
>>>>> qlcnic, netxen, mv643, s2io, myi10ge, bnx2x, ixgbe, vmxnet3
>>>>>
>>>>> One driver seems confused about LRO vs GRO:
>>>>> mlx4 - comments about LRO and depends on LRO but driver is using GRO
>>>>>
>>>>> Drivers with not using ethtool interface to disable LRO:
>>>>> pasemi_mac, sfc, ehea, cxgb3, cxgb4
>>>> cxgb4 uses GRO, not LRO.
>>> Ok. but cxgb3 still uses LRO (or it least calls it lro).
>>>
>> cxgb3 was the driver Herbert implemented GRO on I think, and he converted it
>> to GRO. It possibly has leftover LRO references as it was using LRO before.
>
> There's a fair amount of code setting LRO flags in various structures,
> so either the driver still enables LRO in hardware/firmware or this is
> dead code.
From a quick look it appears to have a per queue lro flag. HW/FW are not
aware of LRO, whatever flags that driver has are for SW. I'd say it's
obsolete but probably not dead code.
>
> Ben.
>
prev parent reply other threads:[~2010-12-06 23:36 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-12-06 20:18 Misuse of LRO, how widespread Stephen Hemminger
2010-12-06 20:30 ` Ben Hutchings
2010-12-06 22:33 ` Stephen Hemminger
2010-12-06 22:35 ` Ben Hutchings
2010-12-10 23:03 ` David Miller
2010-12-06 21:15 ` Dimitris Michailidis
2010-12-06 22:27 ` Stephen Hemminger
2010-12-06 23:05 ` Dimitris Michailidis
2010-12-06 23:22 ` Ben Hutchings
2010-12-06 23:36 ` Dimitris Michailidis [this message]
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