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ASKAP Benchmark Packages

These benchmark packages are available for use to benchmark key algorithms required to image data from the Australian SKA Pathfinder (ASKAP).

The packages in attic were used to benchmark a variety of platforms for the original ASKAP Science Data Processor, and were made widely available to vendors.

The packages in current are more closely aligned with the current processing approach and parameters, and are availavle for on-going benchmarking and acceptance testing.

Hogbom Clean Benchmark (tHogbomClean)

The tHogbomClean benchmark implements the kernel of the Hogbom Clean deconvolution algorithm. This benchmark is quite minimal and actually omits the final step, convolution of the model with the clean beam, but this involves the similar operations to the other steps as far as the CPU is concerned.

Execution of the tHogbomClean benchmarks will require the existence of the point spread function (PSF) image and the dirty image (the image to be cleaned) in the working directory. These are available in the data directory.

The following tHogbomClean benchmarks are available in the current directory. Cleaning generally takes place on a single process, and as such multi-threading is a natural approach to parallelism.

tHogbomCleanOMP

This implementation uses OpenMP to utilize multiple cores in a single shared-memory system.

tHogbomCleanACC

This implementation uses OpenACC to utilize multiple cores in either a single shared-memory CPU system or a single GPU.

Note that older, unmantained versions of these benchmarks are available for a range of platforms in the attic sub-directory.

Convolutional Resamping Benchmark (tConvolve)

This benchmark suite include parallel implementations of Tim Cornwell's original tConvolveBLAS benchmark. The tConvolve benchmark programs measures the performance of a convolutional resampling algorithm as used in radio astronomy data processing. The benchmark is configured to reflect the computing needs of the Australian Square Kilometer Array Pathfinder (ASKAP) Science Data Processor. A more detailed description and some analysis of this algorithm is found in SKA Memo 132.

The following tConvolve benchmarks are available in the current directory. As gridding is independent for each frequency, Taylor term, etc., data-parallelism is a natural approach.

tConvolveMPI

The implementation distributes work to multiple CPU cores or multiple nodes via Message Passing Interface (MPI) much like the ASKAP software, and while it is possible to benchmark an entire cluster the aim of the benchmark is primarily to benchmark a single compute node.

tConvolveACC

This implementation uses OpenACC to utilize multiple cores in either a single shared-memory CPU system or a single GPU.

Note that older, unmantained versions of these benchmarks are available for a range of platforms in the attic sub-directory.

Combined Benchmark (tMajor)

This benchmark combines Convolutional Resamping and Hogbom Clean in a single major cycle / minor cycle imaging and deconvolution loop. It is currently under construction

tMajorACC

Currently under construction Todo: update this document

Other Benchmarks

Todo: update this document

msperf

Benchmark to measure the performance of a filesystem.

mpiperf

Benchmark to measure the performance of a mpi gather.

Instructions

The following examples were generated on a single node of Magnus at the Pawsey Supercomputing Centre.

tHogbomCleanOMP

$ cd current/tHogbomCleanOMP
$ cp ../../data/dirty_4096.img dirty.img
$ cp ../../data/psf_4096.img psf.img
$ export OMP_PROC_BIND=true
$ export OMP_NUM_THREADS=1
$ srun -N 1 -n  1 -c 1 ./tHogbomCleanOMP > tHogbomCleanOMP_nt01.out
$ export OMP_NUM_THREADS=4
$ srun -N 1 -n  1 -c 4 ./tHogbomCleanOMP > tHogbomCleanOMP_nt04.out
$ export OMP_NUM_THREADS=8
$ srun -N 1 -n  1 -c 8 ./tHogbomCleanOMP > tHogbomCleanOMP_nt08.out
$ export OMP_NUM_THREADS=12
$ srun -N 1 -n  1 -c 12 ./tHogbomCleanOMP > tHogbomCleanOMP_nt12.out
$ export OMP_NUM_THREADS=16
$ srun -N 1 -n  1 -c 16 ./tHogbomCleanOMP > tHogbomCleanOMP_nt16.out
$ export OMP_NUM_THREADS=20
$ srun -N 1 -n  1 -c 20 ./tHogbomCleanOMP > tHogbomCleanOMP_nt20.out
$ export OMP_NUM_THREADS=24
$ srun -N 1 -n  1 -c 24 ./tHogbomCleanOMP > tHogbomCleanOMP_nt24.out

Note that when the number of threads is greater than 12, the OpenMP cleaning rate can vary significantly unless text OMP_PROC_BIND is set.

$ grep speedup tHogbomCleanOMP_nt??.out
tHogbomCleanOMP_nt01.out:    Number of threads = 1,  speedup = 0.96139
tHogbomCleanOMP_nt04.out:    Number of threads = 4,  speedup = 3.3542
tHogbomCleanOMP_nt08.out:    Number of threads = 8,  speedup = 5.88056
tHogbomCleanOMP_nt12.out:    Number of threads = 12, speedup = 7.66545
tHogbomCleanOMP_nt16.out:    Number of threads = 16, speedup = 9.79861
tHogbomCleanOMP_nt20.out:    Number of threads = 20, speedup = 11.258
tHogbomCleanOMP_nt24.out:    Number of threads = 24, speedup = 12.158

tConvolveMPI

$ cd current/tConvolveMPI
$ srun -N 1 -n  1 ./tConvolveMPI > tConvolveMPI_np01.out
$ srun -N 1 -n  4 ./tConvolveMPI > tConvolveMPI_np04.out
$ srun -N 1 -n  8 ./tConvolveMPI > tConvolveMPI_np08.out
$ srun -N 1 -n 12 ./tConvolveMPI > tConvolveMPI_np12.out
$ srun -N 1 -n 16 ./tConvolveMPI > tConvolveMPI_np16.out
$ srun -N 1 -n 20 ./tConvolveMPI > tConvolveMPI_np20.out
$ srun -N 1 -n 24 ./tConvolveMPI > tConvolveMPI_np24.out
$ grep 'Continuum gridding performance' tConvolveMPI_np??.out
tConvolveMPI_np01.out:    Continuum gridding performance (per process):   294.649 (Mpix/sec)
tConvolveMPI_np04.out:    Continuum gridding performance (per process):   241.014 (Mpix/sec)
tConvolveMPI_np08.out:    Continuum gridding performance (per process):   195.967 (Mpix/sec)
tConvolveMPI_np16.out:    Continuum gridding performance (per process):   164.975 (Mpix/sec)
tConvolveMPI_np20.out:    Continuum gridding performance (per process):   145.151 (Mpix/sec)
tConvolveMPI_np24.out:    Continuum gridding performance (per process):   126.717 (Mpix/sec)
$ grep 'Continuum degridding performance' tConvolveMPI_np??.out
tConvolveMPI_np01.out:    Continuum degridding performance (per process):   206.756 (Mpix/sec)
tConvolveMPI_np04.out:    Continuum degridding performance (per process):   175.339 (Mpix/sec)
tConvolveMPI_np08.out:    Continuum degridding performance (per process):   142.056 (Mpix/sec)
tConvolveMPI_np16.out:    Continuum degridding performance (per process):   124.577 (Mpix/sec)
tConvolveMPI_np20.out:    Continuum degridding performance (per process):   119.049 (Mpix/sec)
tConvolveMPI_np24.out:    Continuum degridding performance (per process):   113.613 (Mpix/sec)
$ grep 'Spectral gridding performance' tConvolveMPI_np??.out
tConvolveMPI_np01.out:    Spectral gridding performance (per process):    482.345 (Mpix/sec)
tConvolveMPI_np04.out:    Spectral gridding performance (per process):    482.345 (Mpix/sec)
tConvolveMPI_np08.out:    Spectral gridding performance (per process):    431.572 (Mpix/sec)
tConvolveMPI_np16.out:    Spectral gridding performance (per process):    300.912 (Mpix/sec)
tConvolveMPI_np20.out:    Spectral gridding performance (per process):    258.263 (Mpix/sec)
tConvolveMPI_np24.out:    Spectral gridding performance (per process):    224.654 (Mpix/sec)
$ grep 'Spectral degridding performance' tConvolveMPI_np??.out
tConvolveMPI_np01.out:    Spectral degridding performance (per process):    390.47 (Mpix/sec)
tConvolveMPI_np04.out:    Spectral degridding performance (per process):    377.005 (Mpix/sec)
tConvolveMPI_np08.out:    Spectral degridding performance (per process):    348.93 (Mpix/sec)
tConvolveMPI_np16.out:    Spectral degridding performance (per process):    264.512 (Mpix/sec)
tConvolveMPI_np20.out:    Spectral degridding performance (per process):    235.967 (Mpix/sec)
tConvolveMPI_np24.out:    Spectral degridding performance (per process):    204.997 (Mpix/sec)

tConvolveACC

Note that the performance numbers quoted here are the same as those quoted in tConvolveMPI. That is, assuming ~ 12,000 and 8,400 separate processing units for continuum and spectral line observing respectively. If GPUs were used for gridding instead of multi-core CPUs, the reduction in processing units would need to be accounted for in the performance numbers (where here it is assumed that each GPU is a single processing unit or MPI process).