[ofa-general] Re: How to tell what OFED rev a distro derived IB modules?

[Chris Worley]

On Mon, Apr 27, 2009 at 11:51 AM, Vladislav Bolkhovitin <vst at vlnb.net> wrote:
> Chris Worley, on 04/27/2009 07:54 PM wrote:
>>
>> On Mon, Apr 27, 2009 at 5:03 AM, Bart Van Assche
>> <bart.vanassche at gmail.com> wrote:
>>>
>>> On Mon, Apr 27, 2009 at 8:27 AM, Jack Morgenstein
>>> <jackm at dev.mellanox.co.il> wrote:
>>>>
>>>> The OFED distributions may contain features that the mainstream kernels
>>>> and libraries do not support.
>>>> These features frequently require changes in the Infiniband kernel
>>>> modules.  Such changes are in the form
>>>> of kernel patches which are applied to the base mainstream kernel on
>>>> which the OFED release is based.
>>>> A lag between the mainstream kernel and the OFED kernel is unavoidable,
>>>> since the new features are first
>>>> released in the OFED distributions -- and later, gradually (and
>>>> hopefully), these features make there way
>>>> into the upstream kernel.
>>>
>>> I don't doubt that there is a good reason why new features go in the
>>> OFED distribution first and later in the mainstream Linux kernel.
>>
>> My opinion is: IB is still just too bleeding edge, even for the
>> vanilla Linux kernel.
>>
>> Maybe "Upstream First" is the measure of IB achieving stability.
>>
>> SRP (specifically the SCST target code) is my first case in using IB
>> where I've not been able to start with the latest OFED (or IBGD)
>> stable release, as OFED is unsupported by the SRP target code, and had
>> to start with a distro's IB version to get a working SRP target (of
>> which Ubuntu 8.10 provided the only stable SRP target distro for my
>> configuration).
>
> I think, to find out who's guilty, OFED or SRP target driver, you should
> simply try the latest SCST/SRP driver from the SCST SVN trunk with the known
> working OFED. Only make sure you don't have again mixed up older and new
> SCST headers.

SCST's latest ip_srpt hung (which was well documented in the SCST
list) with OFED 1.4 (and 1.4.1rc3)... to which the reply was "SCST
doesn't support OFED, only distros", so the Ubuntu 8.10 was the only
recourse, as it uses more up-to-date drivers from OFED (close to OFED
1.4), which solved the reliability issue.

There were never "mixed up header" issues, as also documented on the SCST list.

Chris