Re: Safe to delete rpcrdma.ko loading start-up code

Sagi Grimberg
2024-05-21T13:05:08Z

On 21/05/2024 15:43, Jason Gunthorpe wrote:
> On Tue, May 21, 2024 at 12:04:02PM +0300, Sagi Grimberg wrote:
>>
>> On 20/05/2024 21:05, Chuck Lever III wrote:
>>> Hi-
>>>
>>> I've tested this with two kinds of systems:
>>>
>>> 1. A system with no physical RDMA devices and no start-up
>>> scripts to load these modules
>>>
>>> 2. A system with physical RDMA devices and with the start-up
>>> scripts that load xprtrdma/svcrdma
>>>
>>> In both cases, after doing an "rmmod rpcrdma", I can mount
>>> a "proto=rdma" mount or start the NFS server, and the module
>>> gets reloaded automatically.
>>>
>>> I therefore believe it is safe to delete the code in the
>>> rdma-core start-up scripts that manually load RPC-related
>>> RDMA support. Either the sunrpc.ko module does this, or NFS
>>> user space handles it. There's no need for the rdma-core
>>> scripting.
>> I didn't know that rdma-core does this... it really shouldn't, the
>> mount should (and does) handle it.
> This is new, it didn't used to do this
>
>> I also see that srp(t) and iser(t) are loaded too.. IIRC these are
>> loaded by their userspace counterparts as well (or at least they
>> should).
> And AFIAK, these don't have a way to autoload at all. autoload
> requires the kernel to call request_module..

nvme/nvmet/isert are requested by the kernel. iser is loaded by iscsiadm.
IIRC srp had a userspace daemon loading it.