Bspec 53421 says: "A URB fence memory is typically performed prior the thread exit message, so that the next thread dispatch that reads that URB memory will see it." Cc: 22.1 <mesa-stable> Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/16665>