[Info-vax] High resolution per-process CPU consumption statistics

[Stephen Hoffman]

On 2020-03-24 00:32:18 +0000, Mark Daniel said:

> Would like to be able to measure process CPU consumed during specified 
> continuous sections of processing.  Only interested in CPU-intensive 
> sections so USER mode consumed relevant.  Imagine inserting calls at 
> the beginning and ending of those sections with a magic number 
> representing CPU consumption/delta/whatever made available.

I'd start with DECset PCA to narrow down where to focus tuning.

This as the timing of large and complex applications can be quite surprising.

Then SDA> PRF and instruction listings, if I really needed to 
investigate the details of specific code-paths.

See the C calls gettimeofday, clock_gettime and clock_getres, too. This 
mechanism is intended to have better accuracy.

I've long wondered whether person that named the $gettim_prec call was 
here making a statement about precision and accuracy. That, and why the 
call even exists, as the low bits in $gettim were always dusty.



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