MPICH, DCMF, and SPI

The ZeptoOS team has enabled IBM CNK's commucation software stack to work with the Zepto compute node Linux environment for high performance computing(HPC) applications, specifically for MPI applications. Performance of MPI applications on the Zepto compute node Linux environment are comparable to that's on CNK.

As in IBM CNK environment, Deep Computing Messaging Framework(DCMF) and System Programming Interface(SPI) are available. You can also write a DCMF code or a SPI code directly if necessary. DCMF is a communication library that provides non-blocking operations. Please refer [DCMF wiki] for some details. SPI is the lowest level user space API for Torus DMA, collective network, BGP specifc lock mechanisms and other compute node specific implementations. There is no public document available right now but almost all header files and source codes are available. Internally MPICH depends on DMCF that depends on SPI.

Compiler wrapper scripts

To run your HPC application on the Zepto environment, first of all, you need to recompile your code with our compile wrapper scripts (see blow) which are installed in your Zepto installation path. We provide the same set of wrapper scripts that IBM provides. Once you have successfully compiled your code, you need to submit it with Zepto kernel profile ( see the Kernel Profile section). Note: only SMP mode is currently supported.

- Wrapper scripts that invoke BGP enhanced GNU compilers 
zmpicc
zmpicxx
zmpif77
zmpif90

- Wrapper scripts that invoke IBM XL compilers
zmpixlc
zmpixlcxx
zmpixlf2003
zmpixlf77
zmpixlf90
zmpixlf95

- Wrapper scripts that invoke IBM XL compilers(thread safe compilation)
zmpixlc_r
zmpixlcxx_r
zmpixlf2003_r
zmpixlf77_r
zmpixlf90_r
zmpixlf95_r

If you need to understand what those script actually do internally, run the wrapper script with the -show option.

Without compiler scripts

In case you can't use those compiler wrapper scripts, please make sure that your makefile or build environemnt points Zepto header files and libraries correctly. An example would be:

/bgsys/drivers/ppcfloor/gnu-linux/bin/powerpc-bgp-linux-gcc  \
-o mpi-test-linux -Wall -O3  -I__INST_PREFIX__/include/   mpi-test.c \
-L__INST_PREFIX__/lib/ -lmpich.zcl  -ldcmfcoll.zcl -ldcmf.zcl  -lSPI.zcl -lzcl \
-lzoid_cn -lrt -lpthread -lm
__INST_PREFIX__/bin/zelftool -e mpi-test-linux

NOTE:

• Replace __INST_PREFIX__ with your actuall Zepto install path
• Don't forget calling the zelftool utility
  • which makes your executable a Zepto Compute Binary to let the Zepto kernel load

all application segments into the big memory area.

The file layout in the zepto install path would be:

|-- bin
|   |-- zelftool
|-- include
|   |-- dcmf.h
|   |-- dcmf_collectives.h
|   |-- dcmf_coremath.h
|   |-- dcmf_globalcollectives.h
|   |-- dcmf_multisend.h
|   |-- dcmf_optimath.h
|   |-- mpe_thread.h
|   |-- mpi.h
|   |-- mpi.mod
|   |-- mpi_base.mod
|   |-- mpi_constants.mod
|   |-- mpi_sizeofs.mod
|   |-- mpicxx.h
|   |-- mpif.h
|   |-- mpio.h
|   |-- mpiof.h
|   `-- mpix.h
`-- lib
    |-- libSPI.zcl.a
    |-- libcxxmpich.zcl.a
    |-- libdcmf.zcl.a
    |-- libdcmfcoll.zcl.a
    |-- libfmpich.zcl.a
    |-- libfmpich_.zcl.a
    |-- libmpich.zcl.a
    |-- libmpich.zclf90.a
    |-- libzcl.a
    `-- libzoid_cn.a