7152779ae0
It was for a failed expriment that tried to mmap() dmabuf memory and find damaged regions to decrease the amount that was eventually used to write to an onscreen, but mmap:ing is only fast enough on intel, and it's only relevant on various server GPUs. For it to be achievable, we need to render to system memory in a way that we don't need to copy it out of OpenGL, but that's currently not possible. Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3443>