Re: [PATCH] kernel-boot: Do not perform device rename on OPA devices

[Dennis Dalessandro <dennis.dalessandro@intel.com>]

On 2/5/2020 2:12 PM, Jason Gunthorpe wrote:
> On Tue, Feb 04, 2020 at 08:55:20AM -0500, Goldman, Adam wrote:
>> From: "Goldman, Adam" <adam.goldman@intel.com>
>>
>> PSM2 will not run with recent rdma-core releases. Several tools and
>> libraries like PSM2, require the hfi1 name to be present.
>>
>> Recent rdma-core releases added a new feature to rename kernel devices,
>> but the default configuration will not work with hfi1 fabrics.
>>
>> Related opa-psm2 github issue:
>>    https://github.com/intel/opa-psm2/issues/43
>>
>> Fixes: 5b4099d47be3 ("kernel-boot: Perform device rename to make stable names")
>> Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
>> Signed-off-by: Goldman, Adam <adam.goldman@intel.com>
>>   kernel-boot/rdma-persistent-naming.rules | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/kernel-boot/rdma-persistent-naming.rules b/kernel-boot/rdma-persistent-naming.rules
>> index 9b61e16..95d6851 100644
>> +++ b/kernel-boot/rdma-persistent-naming.rules
>> @@ -25,4 +25,4 @@
>>   #   Device type = RoCE
>>   #   mlx5_0 -> rocex525400c0fe123455
>>   #
>> -ACTION=="add", SUBSYSTEM=="infiniband", PROGRAM="rdma_rename %k NAME_FALLBACK"
>> +ACTION=="add", SUBSYSTEM=="infiniband", KERNEL!="hfi1*", PROGRAM="rdma_rename %k NAME_FALLBACK"
> 
> We are moving to the new names by default slowly, when wrong
> assumptions are found in other packages they need to be updated and
> their fixes pushed out.
> 
> At some point the major distros will default this to On. People using
> leading edge distros can turn it off with the global switch Leon
> mentioned.
> 
> This is the same process netdev went through when they introduced
> persistent names.
> 
> If I recall, hfi was one of the reason this work was done. HFI has
> problems generating consistent names for its multi-function devices in
> various cases and I NAK'd the kernel hack to try and 'fix' that.

So are you saying you won't take this patch then?

I guess we can work with distros to get the right rules in place outside 
of rdma-core so that things continue to work. It would be better though 
in my opinion to just have that be in rdma-core so no one has to worry 
about it and nothing needs to be globally disabled.

You are correct someone tried to put forth a hack for the flip-flop name 
thing [1]. However even if this was used as a solution for that issue we 
would still have the same library looking for hfi1_0 problem.

[1] https://patchwork.kernel.org/patch/9508879/

-Denny