The current OpenBSD-specific CPU usage code is broken. The `cpu`
parameter of `Platform_setCPUValues` is an integer in the interval
[0, cpuCount], not [0, cpuCount-1]: Actual CPUs are numbered from
1, the “zero” CPU is a “virtual” one which represents the average
of actual CPUs (I guess it’s inherited from Linux’s `/proc/stats`).
This off-by-one error leads to random crashes.
Moreover, the displayed CPU usage is more detailed with system,
user and nice times.
I made the OpenBSD CPU code more similar to the Linux CPU code,
removing a few old bits from OpenBSD’s top(1). I think it will be
easier to understand, maintain and evolve.
I’d love some feedback from experienced OpenBSD people.
The source code correctly states that the maximum PID number in
the OpenBSD kernel is fixed in sys/sys/proc.h, however this was
updated in revision 1.215 (two years ago!) from 32766 to 99999.
Introduction of CP_SPIN sched state broke hard-coded state indexes
resulting in the meters incorrectly reporting bogus intr data instead of
CPU usage. Change hardcoded values to sched.h macros.
Specifically, Platform_signals[] and Platform_numberOfSignals. Both are
not supposed to be mutable. Marking them 'const' puts them into rodata
sections in binary. And for Platform_numberOfSignals, this aids
optimization (aids only Link Time Optimization for now). :)
Signed-off-by: Kang-Che Sung <explorer09@gmail.com>
