For those wishing to make use of modern OpenCL 3.0 capabilities on AMD APUs/SoCs with integrated Radeon graphics using Mesa's Rusticl driver, an improvement was merged this weekend to the RadeonSI driver ahead of this quarter's Mesa 26.1 release.

Karol Herbst of Red Hat and the lead developer of the Rusticl Rust OpenCL driver authored the fix so RadeonSI properly reports unified memory on APUs. Karol noted in the [1]merge request that AMD APUs with this open-source Rust OpenCL driver are hitting the scenario where they have very small discrete vRAM but lots of staging system memory that can also be utilized.

There is a one-liner fix to the RadeonSI driver for properly reporting unified memory on APUs, implementing CL_KERNEL_GLOBAL_WORK_SIZE for custom devices with the Rusticl code, and also a Rusticl driver fix around reporting of global memory on mixed memory devices.

The merge request was authored all the way back in July 2024 and only merged to Mesa 26.1-devel on Sunday. A nice improvement for the upcoming Mesa 26.1 for those wanting to make use of modern OpenCL capabilities with AMD APUs and not wanting to go the route of the ROCm OpenCL driver.



[1] https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/30123