51e2c82023
Per documentation the call to dataExchange API (move memory block between different devices) is permitted only if isDataExchangable() call returned true. While almost all platforms support memory transfer between different devices, in the case when the transfer is attempted between devices belonging to different platforms if they are present on the same machine which can lead to unexpected results. This PR adds a check if dataExchange can be called and if not uses a workaround by initiating memory transfer through host.
Liboffload
This directory contains the implementation of the work-in-progress new API for Offload. It builds on top of the existing plugin implementations but provides a single level of abstraction suitable for implementation of many offloading language runtimes, rather than just OpenMP.
Testing liboffload
The main test suite for liboffload can be run with the check-offload-unit
target, which runs the offload.unittests executable. The test suite will
automatically run on every available device, but can be restricted to a single
platform (CUDA, AMDGPU) with a command line argument:
$ ./offload.unittests --platform=CUDA
Tracing of Offload API calls can be enabled by setting the OFFLOAD_TRACE
environment variable. This works with any program that uses liboffload.
$ OFFLOAD_TRACE=1 ./offload.unittests
---> olInit()-> OL_SUCCESS
# etc
The host plugin is not currently supported.
Modifying liboffload
The main header (OffloadAPI.h) and some implementation details are
autogenerated with tablegen. See the API definition README
for implementation details.