/sys$common/syshlp/helplib.hlb Sys Parameters, SMP_SPINWAIT  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    SMP_SPINWAIT establishes, in 10-microsecond intervals, the amount
    of time a CPU in an SMP system normally waits for access to a
    shared resource. This process is called spinwaiting.

    A timeout causes a CPUSPINWAIT bugcheck.

    The default value is 100000 (100,000 10-microsecond intervals or
    1 second).