CS/CSD/CSG/CSDG would be considerably faster than PLO. CS is implemented in hardware. PLO is implemented in millicode. The millicode obtains a spin lock, performs the requested operations, and releases the lock.
Jim Mulder z/OS Diagnosis, Design, Development, Test IBM Corp. Poughkeepsie NY > From: "Charles Mills" <charl...@mcn.org> > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Date: 01/10/2019 12:59 AM > Subject: Re: Multi CPU interlock question > Sent by: "IBM Mainframe Assembler List" <ASSEMBLER-LIST@LISTSERV.UGA.EDU> > > Take your pick of answers: > > 1. I don't know. > 2. It probably depends on the model. > 3. It probably depends on what exactly is going on with the cache, > contention, etc. > 4. I am going to guess the CS is cheaper than PLO because it is simpler. > > Charles > > > -----Original Message----- > From: IBM Mainframe Assembler List [ mailto:ASSEMBLER-LIST@LISTSERV.UGA.EDU] > On Behalf Of Seymour J Metz > Sent: Wednesday, January 9, 2019 11:52 AM > To: ASSEMBLER-LIST@LISTSERV.UGA.EDU > Subject: Re: Multi CPU interlock question > > How does the cost of CS/CDS compare to PLO? >
