User manual

Miscellaneous Notes
69
Time Machine (OS X)
We recommend disabling Time Machine automatic copying of VAX MP disk image files. If Time
Machine starts copying these files while VAX MP is running, this can cause slowdown of VAX MP
or cause it to freeze for a long time while the file is being copied.
Refer to “Time Machine” section in article http://labs.hoffmanlabs.com/node/922 for
references on how to disable copying of disk image files by Time Machine.
OpenVMS bugcheck CPUSANITY
If you observe OpenVMS bugcheck with code CPUSANITY (“CPU sanity timer expired”) make
sure you have SYSGEN parameter TIME_CONTROL set to values either 2 or 6. Bit 1 must be set in
the parameter. Current release of VAX MP does not support OpenVMS execution with
TIME_CONTROL set to 0.
OpenVMS bugcheck CPUSPINWAIT
If you observe OpenVMS bugcheck with code CPUSPINWAIT (“CPU spinwait timer expired”) this
may indicate that you have values of SYSGEN parameters SMP_SPINWAIT and
SMP_LNGSPINWAIT set too low, in this case reset them to default. If parameters are at their
default value
1
or higher, this may indicate a possible bug in VAX MP.
In the latter case please report the crash to SIMH mailing list ideally submitting on request
details of your VAX MP SIMH set up, including: simulator startup script file, exact VAX MP
version, console output during early startup and before the crash, OpenVMS version, SYSGEN
parameter file (typically VAXVMSSYS.PAR unless used different file during SYSBOOT) and
OpenVMS crash dump file (SYSDUMP.DMP).
Increasing values of SMP_SPINWAIT and SMP_LNGSPINWAIT may resolve the problem, however
under most circumstances default values
2
should be amply sufficient.
As a sure-fire temporary fix, setting SYSGEN parameter TIME_CONTROL to 6 should disable
OpenVMS SMP timeout bugchecks.
If you are using native interlock mode (VSMP INTERLOCK=NATIVE), falling back to portable
interlock mode might also provide a temporary fix.
1
100,000 (1 second) for SMP_SPINWAIT; 950,000 (9.5 seconds) for SMP_LNGSPINWAIT. Note that default value of
SMP_LNGSPINWAIT suggested by VAX MP is less than standard OpenVMS default value of 30 seconds. VAX MP
uses smaller value to avoid busy-wait loop iteration counter overflow problem mentioned further. 9.5 seconds
must be amply (indeed, over-amply) sufficient for any legitimate SMP synchronizaton.
2
SMP_SPINWAIT set to 100000 or 1 second.
SMP_LNGSPINWAIT set to 950000 or 9.5 seconds.