SDMA Application Scenarios

System Direct Memory Access (SDMA) is a distributed, decoupled DMA engine designed for high-bandwidth, low-latency data movement. By default, SDMA is disabled in HMPI. To use SDMA, add -x UCX_TLS=sdma to the boot options of the mpirun command. SDMA must be used in conjunction with POSIX or SysV through -x UCX_TLS=posix,sdma or -x UCX_TLS=sysv,sdma. For Kunpeng 920 72F series products, it is recommended that Hyper MPI and SDMA be used when PPN is fewer than or equal to 128.

Example:

mpirun --allow-run-as-root -np 2 -x UCX_TLS=posix,sdma osu_bw