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For only one microprocessor unit, the load average output by top could be understood that if it's above 1.0 then there are jobs waiting. But if we have n number of cores on a multicore system with l*n logical cores (on my Intel CPU n=6 and l*n = 12 so the output from nproc is 12), should we divide the load average by the output from nproc to see if that number is above 1 to understand if there are (on average) jobs waiting, or is it better to use htop to understand if a parallel multicore system is getting too much average load?

I think that my method was wrong but the conclusion was right when I saw that an average load was above 10 top, I checked with ps which process was expensive and found an overflow from a running program, but if that machine actually has output from nproc > 10 then it would not really have been cause for investigation if I had known that. Do you agree?

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Your assumption is correct, you divide the load average across the cores. To understand load averages better I highly recommend this article by Brendan Gregg http://www.brendangregg.com/blog/2017-08-08/linux-load-averages.html

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  • Well If I'm reading it correctly just dividing across would not work I guess given if the system is under heavy load that does mean heavy CPU load it can be load IO load too (like thread / process waiting on slow IO etc)
    – Noobie
    Commented Jul 10, 2021 at 9:53

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