On Apr 17, 2011, at 05:58, John McKown wrote:
>
> Please forgive my ignorance, but I don't know what you mean by "n"
> locked operations to per performed simultaneously. Do you mean that the
> other three operations: TS, CS, and CDS cause all other CPs in a CEC to
> stop processing instructions (at an instruction boundary, I would guess)
> while they execute on the given CP? If so, then YUCK! For some reason I
> thought that they simply "locked" access to the storage under
> consideration and stopped other CPs if they tried to access that
> particular real storage area, but if the other CPs were doing something
> in another area of storage, that they continued to do normal processing.
> Is this "stop other CPs in the CEC" what is meant when the PoPs says: "A
> serialization function is performed before the operand is fetched and
> again after the operation is completed."
>
According to the PoOp ("PrOp" according to some), there is an instruction
which performs "a serialization and checkpoint-synchronization function"
While making no data references to storage. This statement would have no
meaning if the scope of the serialization did not extend beyond the
storage referenced by the serializing instruction itself.
-- gil
