> After reading quickly the thread, I still believe that's sound like a > kernel regression which broke existing userspace applications. > > So a patch must be applied on the kernel to fix that regression.
When AF_IB was added to the kernel, corresponding changes were added to the librdmacm. Those changes to the librdmacm are the cause of the issue. The kernel rdma cm previously supported a single 'query' call. With AF_IB, it supports the original call, plus 3 additional calls. The problem is the librdmacm using the newer query calls. > Introducing AF_IB must not have changed the behavor for existing > applications. Existing applications must not need a new librdmacm when > they don't use newer kernel extensions. An older version of the librdmacm that does NOT support AF_IB should work fine. - Sean
