Subject: Re: forcedeth driver hangs under heavy load

From: stephen mulcahy <[email-masked]>
Date: Tue, 13 Apr 2010 15:49:04 +0100

Eric Dumazet wrote:
> Le mardi 13 avril 2010 à 15:27 +0100, stephen mulcahy a écrit :
>> Ok, I've tried both of the following with my reproducer
>>
>> 1. ethtool -K eth0 tso off
>>
>> RESULT: reproducer causes multiple hosts to be come unresponsive on 
>> first run.
>>
>> 2. ethtool -K eth0 tx off
>>
>> RESULT: reproducer runs three times without any hosts becoming unresponsive.
>>
>> -stephen
> 
> Thanks Stephen !
> 
> Now some brave fouls to check the 6410 lines of this driver ? ;)
> 
> Question of the day : Why TSO is broken in forcedeth ?
> Is it generically broken or is it broken for specific NICS ?
> 

Actually, it is only when tx-checksumming is turned off that the problem 
  doesn't occur (so I'm not sure TSO is the problem).

Additionally, a google also turns up this existing Debian bug 
http://bugs.debian.org/506419 which seems to be related.

-stephen