Multi-SPMD Programming Model with YML and XcalableMP
227
5 Experiments
In this section, we demonstrate the performance of the mSPMD programming model
and our implementation.
Table 1 shows the specification of the K computer, which has been used for the
experiments.
In our experiments, the Block Gauss–Jordan (BGJ) method, which computes
the inversion of a matrix A, has been considered. Figure 7 shows the algorithm
of the BGJ method. The workflow for the BGJ method written in YvetteML
has been shown in Fig. 5. As shown in Table 2, tasks in the workflow process
block(s). In order to investigate the performance over different levels of hierarchical
parallelism:
• the total size of the matrix A is fixed to 32,768 × 32,768, but the number of
blocks is varied from 1 × 1 to 16 × 16.
• the total number of processes (cores) for a workflow is fixed to 4096, but the
number of processes for each task is varied from 8 to 4096.
Table 1 Specification of K
computer
CPU
Fujitsu SPARC64VIIIfx, 8 core, 2.00 GHz
Memory 16 GB , 64 GB/s
Cache
L1: 32 + 32 KB/core, L2: 6 MB/core
Network Tofu (6D mesh/torus) Interconnect
5 GB/s × 2
Fig. 7 Algorithm of the Block Gauss–Jordan method
227
5 Experiments
In this section, we demonstrate the performance of the mSPMD programming model
and our implementation.
Table 1 shows the specification of the K computer, which has been used for the
experiments.
In our experiments, the Block Gauss–Jordan (BGJ) method, which computes
the inversion of a matrix A, has been considered. Figure 7 shows the algorithm
of the BGJ method. The workflow for the BGJ method written in YvetteML
has been shown in Fig. 5. As shown in Table 2, tasks in the workflow process
block(s). In order to investigate the performance over different levels of hierarchical
parallelism:
• the total size of the matrix A is fixed to 32,768 × 32,768, but the number of
blocks is varied from 1 × 1 to 16 × 16.
• the total number of processes (cores) for a workflow is fixed to 4096, but the
number of processes for each task is varied from 8 to 4096.
Table 1 Specification of K
computer
CPU
Fujitsu SPARC64VIIIfx, 8 core, 2.00 GHz
Memory 16 GB , 64 GB/s
Cache
L1: 32 + 32 KB/core, L2: 6 MB/core
Network Tofu (6D mesh/torus) Interconnect
5 GB/s × 2
Fig. 7 Algorithm of the Block Gauss–Jordan method