Subject: Re: 3.4.1 and 3.5-rc1 Packet lost at 250Mb/s

From: Andre Tomt <[email-masked]>
Date: Mon, 08 Oct 2012 14:32:52 +0200

On 08. okt. 2012 14:13, Eric Dumazet wrote:
> On Mon, 2012-10-08 at 14:00 +0200, Andre Tomt wrote:
>> On 08. okt. 2012 12:49, Nieścierowicz Adam wrote:
>>> W dniu 08.10.2012 11:47, Eric Dumazet napisał(a):
>>>> Anyway you dont say where are drops, (ifconfig give us very few drops)
>>>
>>> you can see no losses(drop), but a temporary decline in traffic on the
>>> interface to 0kb/s
>>
>> This sounds very familiar, could it be something similar to:
>> http://marc.info/?l=linux-netdev&m=134594936016796&w=3
>>
>> The chip seems to be of the same family (though not model)
>
> Yes, but Adam says 3.4.1 already has a problem, while
> commit 2cb7a9cc008c25dc03314de563c00c107b3e5432 is in 3.5 only.
 >
> Since Adam uses Intel e1000e, it could be the BQL related problem.

The other chips have had DMA burst flag enabled for longer, so that he 
sees the same problem in 3.4 while I'm not makes sense. Hmm, as 3.4 is 
when BQL went in (IIRC) it seems very likely that this BQL issue is the 
problem for both of us.

> (Not sure if Intel guys finally fixed the problem, if not, its really
> insane)
>
> http://patchwork.ozlabs.org/patch/163298/

Ugh. :)