Efficient Strict-Binning Particle-in-Cell Algorithm for Multi-Core SIMD Processors


Particle-in-Cell (PIC) codes are widely used for plasma simulations. On recent multi-core hardware, performance of these codes is often limited by memory bandwidth. We describe a multi-core PIC algorithm that achieves close-to-minimal number of memory transfers with the main memory, while at the same time exploiting SIMD instructions for numerical computations and exhibiting a high degree of OpenMP-level parallelism. Our algorithm keeps particles sorted by cell at every time step, and represents particles from a same cell using a linked list of fixed-capacity arrays, called chunks. Chunks support either sequential or atomic insertions, the latter being used to handle fast-moving particles. To validate our code, called Pic-Vert, we consider a 3d electrostatic Landau-damping simulation as well as a 2d3v transverse instability of magnetized electron holes. Performance results on a 24-core Intel Skylake hardware confirm the effectiveness of our algorithm, in particular its high throughput and its ability to cope with fast moving particles.


Yann Barsamian, Arthur Charguéraud, Sever A. Hirstoaga, and Michel Mehrenberger
Euro-Par: International European Conference on Parallel and Distributed Computing, August 2018