"Shane" <ibm-m...@tpg.com.au> wrote in message news:<20111220123112.2a437a52@xpfs>... > On Mon, 19 Dec 2011 09:20:16 -0500 Tom Russell wrote: > > > PR/SM dispatches Logical CPs not Logical Partitions. <SNIPPAGE>
- I am quite sure that pr/sm always dispatched Logical CPs and Amdahls MDF dispatched entire domains (their word for lpar). <snippage> PR/SM and LPARs are IBM's answer to MDF (Multiple Domain Facility and Domains). In fact, IBM was AMDAHL's second customer to pay for MDF. But because the machine they had wasn't ready to be field upgraded, IBM wasn't the second customer to have MDF (man, lots of memories have been awakened by this posting). Through the 5990 machines, all LPs were dispatched simultaneously in a Domain. The idea was that we did not want to cause a spin lock loop problem that would cause ACR. We also were trying to solve a problem with I/O elongation (a domain would start an I/O, lose dispatch, the I/O would complete and the interrupt would be "hanging" until the Domain was dispatched again). We had discussed asynchronous dispatch, but it was decided to not implement it. Then came the big layoff of 1989 just after Thanksgiving... I have no idea what happened after that as I never saw any AMDAHL machines after the 5990-1400s in any shop where I worked. I do know that IBM implemented asynchronous dispatch. When, I don't know. And the particulars I don't know. And I don't work in POK so I don't have access to the LPAR - PR/SM logic, so I honestly can't speak to that at all. Regards, Steve Thompson Staff Software Engineer Connect:Direct for z/OS IBM - Software Group (469) 524-2622 sthomp...@us.ibm.com ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
