FreeBSD: scale CPU% usage on swap time #606
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| if (sysctlbyname("kern.ccpu", &ccpu, &size, NULL, 0) == -1) { | ||
| ccpu = 0; | ||
| } | ||
| const double decayfactor = log(ccpu / kernelFScale); |
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kernelFScale might be zero. Not ensured non-zero by the code querying this from the syscall.
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htop/freebsd/FreeBSDProcessList.c
Lines 138 to 142 in feec16c
You mean kern.fscale might be 0? Is that possible?
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Highly unlikely, given that there's other code already that does a similar division and I'm not aware of any bug reports regarding this. Mostly DiD note.
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Actually just looking at the remarked upon code part: ccpu is set to 0, which will cause a math error with the following calculation for decayfactor. I don't think that's right?
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I've made pull request #1275 that would reject zero kern.fscale value.
cgzones
added
the
needs-discussion 🤔
See https://forums.freebsd.org/threads/how-does-cpu-utilization-is-calculates.12108/
and https://ess.cs.tu-dortmund.de/lockdoc-elixir/freebsd-lockdoc/lockdoc-v13.0-0.6/source/bin/ps/print.c#L650
Closes: #602