- Rediff openucx-s390x-support.patch as p1 to be in line with
potential git-generated patches.

- Switch to version 1.2.1 (Fate#324050)
Previous 1.3+ version was based on a development branch.
Supported platforms
- Shared memory: KNEM, CMA, XPMEM, SYSV, Posix
- VERBs over InfiniBand and RoCE.
VERBS over other RDMA interconnects (iWarp, OmniPath, etc.) is available
for community evaluation and has not been tested in context of this release
- Cray Gemini and Aries
- Architectures: x86_64, ARMv8 (64bit), Power64
Features:
- Added support for InfiniBand DC and UD transports, including accelerated verbs for Mellanox devices
- Full support for PGAS/SHMEM interfaces, blocking and non-blocking APIs
- Support for MPI tag matching, both in software and offload mode
- Zero copy protocols and rendezvous, registration cache
- Handling transport errors
- Flow control for DC/RC
- Dataypes support: contiguous, IOV, generic
- Multi-threading support
- Support for ARMv8 64bit architecture
- A new API for efficient memory polling
- Support for malloc-hooks and memory registration caching