[openib-general] Performance Degradation with OFED v. Voltaire

[Eitan Zahavi]

Michael S. Tsirkin wrote:
>>  > I think Eric described the major differences earlier on, here it is, see
>>  > second half:
>>
>> OK, I forgot about that.
>>
>> I guess one last thing to check would be the MTU being used for the RC
>> connections.  Since this is PCI-X HW then the MTU should be 1024 for
>> best throughput (instead of the max MTU of 2048).
>>     
>
> The MTU issue is described in the OFED release notes.
> You must turn the Tavor work-around for it on in opensm.
> This was introduced late in release cycle to it was deemed safer
> to make it off by default.
>
> By the way, Eitan, Hal, can we turn this on by default now?
> This was we'll get more feedback from people, and we'll still have
> time to turn it off before release if this unexpectedly creates issues.
>
>   
I agree that we should enable this feature by default now.

EZ