Errata patches for pmapglobal have been released for OpenBSD 6.8 and 6.9. Recent Intel machines could crash or hang as global mappings were not flushed from TLB.
Binary updates for the amd64 platform are available via the syspatch utility. Source code patches can be found on the respective errata page: https://www.openbsd.org/errata68.html https://www.openbsd.org/errata69.html As these affect the kernel, a reboot will be needed after patching.