ZPIC - OmpSs-2

ZPIC is a 2D plasma simulator using the widely used PIC (particle-in-cell) algorithm. The program uses a finite difference model to simulate eletromagnetic plasma events. These version is an adaptation of ZPIC, so it can be executed in parallel using the OmpSs-2 programming model. The original serial code belongs to the ZPIC suite.

Features

OmpSs:

• Rows decomposition
• Parallelism based on tasks and data dependencies (OmpSs-2)
• No taskwait (or synchronism) between iterations of the simulation (OmpSs-2)

OmpSs@OpenAcc (under development):

• Rows decomposition
• Parallelism based on tasks and data dependencies (OmpSs-2)
• No taskwait (or synchronism) between iterations of the simulation (OmpSs-2)
• The OpenAcc kernels are integrated into OmpSs tasks
• Hybrid structure for the particles (Structure of Arrays (SoA) for GPU and Array of Structure (AoS) for CPU)
• Manual allocation of regions to be execute in the GPU (based on a percentage of the total number of regions)
• Bucket Sort every 15 iterations

OpenAcc:

• Based on the serial version
• All computation are done in the GPU
• Particles use a Structure of Array (SoA) to improve GPU performance
• Bucket Sort every 15 iterations

Plasma Experiments / Input

In the same way of the original code, the simulation paramenters are set in a .c file in input folder that are later included in the main.c

Two widely known plasma experiments - LWFA and Weibel Instability - are already included. Each experiment have a smaller and a larger variant.

Output

The same file used to set the parameters of the simulation defines the ouput files and the frequency of the output (in terms of simulation iterations).

ZDF Format

Like the original ZPIC, both serial and pure OmpSs-2 versions supports the ZDF file format. For more information, please visit the ZDF repository.

In the future, all the versions will have support for this file format.

CSV Format

Besides the ZDF files, ZPIC can produce .csv files (delimiter = ";") for the following parameters:

• Charge map (for each particle type)
• Eletric field magnitude
• Magnetic field magnitude
• EM fields' energy
• Particles' energy

Compilation and Execution

OmpSs:

make
./zpic <Number of Regions>

OpenAcc/Serial:

make
./zpic

OmpSs@OpenAcc (under development):

make
./zpic <Number of Regions> <Percentage of regions dedicated to GPU> <Number of GPU regions>

Compilation requirements:

• Nanos6 Runtime
• Mercurium Compiler