> Another element of paging that has not been referenced is the ability to > handle all of the swap set size in parallel. If the swap set size is 120 > pages then the old practice was to have at least four LOCALS so each thirty > page block of pages could be swapped-in in parallel. While swapping, like > paging, is not as prevalent as it once was I'm wondering if the swap set > size is still one of the principal guidelines for the number of locals that > should be defined.
Starting with z/OS 1.8, physical swapping is no longer done at all. Block paging has not been done for quite a while either. There can be some trimming done for address spaces when they get logically swapped, and before global LRU is done. So those pages might get written to contiguous slots to help the throughput of the output I/O. But with no swapping and block paging, they will come back in via individual page faults, with no relation to the order in which they were written, and probably as separate I/O operations. I am not trying to say that is a good thing, just saying how it works now, so that you don't spend time trying to design your paging configuration to accommodate former behavior of the operating system. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@bama.ua.edu with the message: INFO IBM-MAIN
