Intel's Iris Gallium3D Driver Working On Better GPU Recovery Handling

While Intel's Iris Gallium3D driver is not enabled by default and considered still experimental in its support of Broadwell graphics and newer, in all of our tests thus far it's been working out very well and haven't encountered any hangs so far in our tested OpenGL workloads. But with no OpenGL driver being immune from potential GPU hangs, a patch series is pending to improve the GPU recovery heuristics.

Longtime open-source Intel Linux graphics developer Chris Wilson sent out a set of three patches this morning for handling of GPU recovery within the Iris driver. In particular, to opt-out of the Linux kernel's automatic GPU recovery and replay. That approach doesn't work out well for Iris where its batches are constructed incrementally and thus the replay following a reset would likely cause issues due to missing state. With this patch series, the Iris driver will instead re-construct a fresh context for the next batch when the kernel indicates a GPU hang.

The set of patches improving the GPU recovery behavior for the Iris driver in Mesa can be found here. The Iris driver is set to makes its initial debut in Mesa 19.1 due out around the end of May, still giving plenty of time for Intel graphics driver developers to make more improvements to this next-gen OpenGL driver ahead of its formal debut.