[Info-vax] What choices are available to the OpenVMS Process Scheduler once all the CPUs are in use?

[Stephen Hoffman]

On 2016-02-11 17:37:20 +0000, Bob Gezelter said:

> I find it interesting that with 32 processes CUR and 120 COM, the CPU 
> is reported only 20% busy (I presume that includes all modes; I could 
> easily believe that only 20% was User mode).

Ayup.   20% user mode is entirely believable here, actually.
That'd be pretty good user mode time, for some of the boxes I've 
profiled and tuned.
Have worked with more than a few where adding cores reduced aggregate 
system performance.
Boxes with lots of cores tend to encounter overhead (eventually); of 
apps spending more than a little time in mpsync and friends.
Kind of like big companies with lots and lots of cost centers, often 
with conflicting goals or requirements or funding models.   But I 
digress.
Load T4.  Collect data.  Review.  Theorize.  Make one change.   Collect 
data to test.   Revert the change, or proceed to the next theory.   
Lather.  Rinse.  Repeat.


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