Re: Auto Tuning

["Mark S. Waterbury" <mark.s.waterbury@xxxxxxx>]

Hello, all:

With all the talk of "tuning" OS/400, I seem to recall, back when IBM first
introduced the RISC-based AS/400s, there were major internal changes
"under the hood" due to the fact that the RISC PowerPC processors were
so much faster than the IMPI CISC processors.

I seem to recall that someone (perhaps an IBMer) told me that those
values specified for the "timeslice" no longer directly affect the internal
timeslice used by the RISC processors. The machines are so much faster,
and the PowerPC processes so many more instructions per second, that
IBM decided to "ignore" that parameter, or only uses it as a "guideline"
of some sort... internally they use a much, much smaller timeslice...

Especially now that OS/400 supports threads and multi-threading within
a single job/process.

In other words, the external job level values you specify for timeslice etc.
no longer directly influence how SLIC assigns the actual machine "time
slice" at the level of the MI task.

(I am not sure what those system values really do any more.)

Hope that helps...

Mark S. Waterbury