[all-commits] [llvm/llvm-project] 5c22b9: Reland [OpenMP][libomptarget] Enable parallel copi...

[Jan Patrick Lehr via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5c22b907dc557d739d5141fad04acac9c97c09b9
      https://github.com/llvm/llvm-project/commit/5c22b907dc557d739d5141fad04acac9c97c09b9
  Author: Jan Patrick Lehr <jplehr at users.noreply.github.com>
  Date:   2023-11-14 (Tue, 14 Nov 2023)

  Changed paths:
    M openmp/libomptarget/plugins-nextgen/amdgpu/src/rtl.cpp

  Log Message:
  -----------
  Reland [OpenMP][libomptarget] Enable parallel copies via multiple SDM… (#72307)

…A engines (#71801)

This enables the AMDGPU plugin to use a new ROCm 5.7 interface to
dispatch asynchronous data transfers across SDMA engines.

The default functionality stays unchanged, meaning that all data
transfers are enqueued into a H2D queue or an D2H queue, depending on
transfer direction, via the HSA interface used previously.

The new interface can be enabled via the environment variable
`LIBOMPTARGET_AMDGPU_USE_MULTIPLE_SDMA_ENGINES=true` when libomptarget
is built against a recent ROCm version (5.7 and later). As of now,
requests are distributed in a round-robin fashion across available SDMA
engines.