> MVS (and vm370) gets total cpu busy by clocking in and out of wait state > and subtracting it from elapsed. however vm370 does that also for every > other thing it does also ... so all the accounted for time plus wait > state time should come up to elapsed time (there may be tiny slop doing > the clock instructions ... or if PR/SM underneath is doing something) > > the detailed MVS capture ratio discussions imply that MVS isn't even > bothering to do the clock accounting for large parts of the kernel (and > in some cases has been as high as 60%).
In z/OS 2.1, we started collecting Timer DIE (Disabled Interrupt Exit) CPU time in LCCX_TimerDIE_CPUTIME. This has traditionally been a significant contributor to uncaptured time, including, for example, SRM and RMF timer-driven processing. I am not aware of any IBM products using this information yet, so this probably still is included in "uncaptured time". But at least we are collecting the data now, so that it could be reported separately as a new component of captured time, in the future. Jim Mulder z/OS System Test IBM Corp. Poughkeepsie, NY ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
