Class: Duffy::System

Inherits:
Object
  • Object
show all
Defined in:
lib/duffy/system.rb

Overview

This is linux specific (for now) and will return 1 for everything on other systems.

Class Method Summary collapse

Class Method Details

.cores ⇒ Object

How many actual CPU cores do we have not including Hyperthreading Linux: “cpu cores” in cpuinfo is on a per physical processor basis, so we multiply by the number of CPUs Mac: hw.physicalcpu



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# File 'lib/duffy/system.rb', line 25

def cores
  case RUBY_PLATFORM
    when /linux/  then (File.read('/proc/cpuinfo').scan(/^cpu cores.*/).first.scan(/\d+$/).first.to_i rescue 1) * cpus
    when /darwin/ then `sysctl -n hw.physicalcpu`.to_i rescue 1
    else 1
  end
end

.cpu_percent ⇒ Object

The system’s current CPU utilization. Darwin: Get a list of all processes’ CPU percentage and add them up. Accurate to a couple percent vs. Activity Monitor. Linux: Read /proc/stat twice and take the difference to give cpu time used in that interval.



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# File 'lib/duffy/system.rb', line 51

def cpu_percent
  case RUBY_PLATFORM
    when /darwin/ then (`ps -A -o %cpu`.lines.map(&:to_f).inject(:+) rescue 0) / threads
    when /linux/  then proc_diff rescue 0
    else 0
  end
end

.cpus ⇒ Object

How many Physical CPUs do you have. Linux: Detected by counting unique physical IDs Mac: hw.packages



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# File 'lib/duffy/system.rb', line 14

def cpus
  case RUBY_PLATFORM
    when /linux/  then File.read('/proc/cpuinfo').scan(/^physical id.*/).uniq.count rescue 1
    when /darwin/ then `sysctl -n hw.packages`.to_i rescue 1
    else 1
  end
end

.sane_load ⇒ Object

What is a sane number of threads to use for data processing. Only using physical cores is a waste, using all logical cores decreases performance.



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# File 'lib/duffy/system.rb', line 44

def sane_load
  (cores + threads) / 2
end

.threads ⇒ Object

How many threads does the system have.



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# File 'lib/duffy/system.rb', line 34

def threads
  case RUBY_PLATFORM
    when /linux/  then File.read('/proc/cpuinfo').scan(/^processor\s*:/).size rescue 1
    when /darwin/ then `sysctl -n hw.ncpu`.to_i rescue 1
    else 1
  end
end