Module: LinuxStat::CPU

Defined in:
lib/linux_stat/cpu.rb

Class Method Summary collapse

Class Method Details

.available_governors ⇒ Object

Returns an array of governors for each CPU as a Hash.

For example:

LinuxStat::CPU.available_governors

=> {"cpu0"=>["performance", "powersave"], "cpu1"=>["performance", "powersave"], "cpu2"=>["performance", "powersave"], "cpu3"=>["performance", "powersave"]}

If the information isn’t available, it will return an empty Hash.



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# File 'lib/linux_stat/cpu.rb', line 287

def available_governors
  @@scaling_av_g ||= cpus.map { |x|
    [File.split(x)[-1], File.join(x, 'cpufreq/scaling_available_governors'.freeze)]
  }

  h = {}
  @@scaling_av_g.each { |id, file|
    h.merge!(id => IO.read(file).split.each(&:strip!)) if File.readable?(file)
  }

  h
end

.count ⇒ Object

Returns the total number of CPU available for the sysetm.

It returns an Integer.

If the information isn’t available, it will return nil.



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# File 'lib/linux_stat/cpu.rb', line 86

def count
  @@cpu_count ||= LinuxStat::Sysconf.processor_configured
end

.count_online ⇒ Object

Returns the total number of CPU online in the sysetm.

It first reads /proc/stat, if that fails, it will read /sys/devices/system/cpu/online, if that fails it will open /proc/cpuinfo. If neither of the procedures work, it will get the LinuxStat::Sysconf.processor_online

It opens /sys/devices/system/cpu/offline and performs various job to get one Ruby array.

If the information isn’t available, it will return an empty Array.



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# File 'lib/linux_stat/cpu.rb', line 103

def count_online
  @@cpuinfo_file ||= '/proc/cpuinfo'.freeze
  @@cpuinfo_readable ||= File.readable?(@@cpuinfo_file)

  @@stat_file ||= '/proc/stat'.freeze

  # Not much slow, not blazing fast, somewhat reliable
  get_online = online

  if !get_online.empty?
    get_online.length
  elsif @@cpuinfo_readable
    # Way slower but reliable!
    IO.readlines(@@cpuinfo_file).count { |x| x.strip[/\Aprocessor.*\d*\z/] }
  else
    # Way faster but absolutely unrealiable!
    LinuxStat::Sysconf.processor_online
  end
end

.cur_freq ⇒ Object

Returns a Hash with current core frequencies corresponding to the CPUs.

For example:

LinuxStat::CPU.cur_freq

=> {"cpu0"=>1999990, "cpu1"=>2000042, "cpu2"=>2000016, "cpu3"=>2000088}

If the information isn’t available, it will return an empty Hash.



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# File 'lib/linux_stat/cpu.rb', line 197

def cur_freq
  @@cur_f ||= cpus.map { |x|
    [File.split(x)[-1], File.join(x, 'cpufreq/scaling_cur_freq'.freeze)]
  }

  h = {}
  @@cur_f.each { |id, file|
    h.merge!(id => IO.read(file).to_i) if File.readable?(file)
  }

  h
end

.governor ⇒ Object

Returns the corresponding governor of each CPU.

The return type is a Hash.

For example:

LinuxStat::CPU.governor

=> {"cpu0"=>"powersave", "cpu1"=>"powersave", "cpu2"=>"performance", "cpu3"=>"performance"}

If the information isn’t available, it will return an empty Hash.



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# File 'lib/linux_stat/cpu.rb', line 265

def governor
  @@scaling_g ||= cpus.map { |x|
    [File.split(x)[-1], File.join(x, 'cpufreq/scaling_governor'.freeze)]
  }

  h = {}
  @@scaling_g.each { |id, file|
    h.merge!(id => IO.read(file).tap(&:strip!)) if File.readable?(file)
  }

  h
end

.max_freq ⇒ Object

Returns a Hash with max core frequencies corresponding to the CPUs.

For example:

LinuxStat::CPU.max_freq

=> {"cpu0"=>2000000, "cpu1"=>2000000, "cpu2"=>2000000, "cpu3"=>2000000}

If the information isn’t available, it will return an empty Hash.



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# File 'lib/linux_stat/cpu.rb', line 241

def max_freq
  @@min_f ||= cpus.map { |x|
    [File.split(x)[-1], File.join(x, 'cpufreq/scaling_max_freq'.freeze)]
  }

  h = {}
  @@min_f.each { |id, file|
    h.merge!(id => IO.read(file).to_i) if File.readable?(file)
  }

  h
end

.min_freq ⇒ Object

Returns a Hash with max core frequencies corresponding to the CPUs.

For example:

LinuxStat::CPU.min_freq

=> {"cpu0"=>2000000, "cpu1"=>2000000, "cpu2"=>2000000, "cpu3"=>2000000}

If the information isn’t available, it will return an empty Hash.



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# File 'lib/linux_stat/cpu.rb', line 219

def min_freq
  @@min_f ||= cpus.map { |x|
    [File.split(x)[-1], File.join(x, 'cpufreq/scaling_min_freq'.freeze)]
  }

  h = {}
  @@min_f.each { |id, file|
    h.merge!(id => IO.read(file).to_i) if File.readable?(file)
  }

  h
end

.model ⇒ Object

Returns the model of processor.

If the information isn’t available, it will return en empty string.

The output is also cached (memoized) ; as changing the value in runtime is unexpected.



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# File 'lib/linux_stat/cpu.rb', line 184

def model
  @@name ||= cpuinfo.find { |x| x.start_with?('model name') }.to_s.split(?:)[-1].to_s.strip
end

.offline ⇒ Object

Returns the total number of CPU offline in the sysetm.

It opens /sys/devices/system/cpu/offline and performs various job to get one Ruby array.

If the information isn’t available, it will return an empty Array.



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# File 'lib/linux_stat/cpu.rb', line 163

def offline
  @@offline_file ||= '/sys/devices/system/cpu/offline'.freeze
  @@offline_readable ||= File.readable?(@@offline_file)
  return [] unless @@offline_readable

  ret = []
  IO.read(@@offline_file).split(?,.freeze).each { |x|
    x.strip!
    c = x.split(?-.freeze).map(&:to_i)
    ret.concat(c.length == 2 ? Range.new(*c).to_a : c)
  }

  ret
end

.online ⇒ Object

Returns the total number of CPU online in the sysetm.

It will read /proc/stat to get the info.

If the info isn’t available, it reads /sys/devices/system/cpu/onfline and performs various job to get one Ruby array.

If the information isn’t available, it will return an empty Array.



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# File 'lib/linux_stat/cpu.rb', line 132

def online
  @@online_file ||= '/sys/devices/system/cpu/online'.freeze
  @@online_readable ||= File.readable?(@@online_file)

  @@stat_file ||= '/proc/stat'.freeze

  ret = []

  if stat?
    IO.readlines(@@stat_file).map { |x|
      v = x.strip[/\Acpu\d*/] &.[](/\d/)
      ret << v.to_i if v
    }
  elsif @@online_readable
    IO.read(@@online_file).split(?,.freeze).each { |x|
      x.strip!
      c = x.split(?-.freeze).map(&:to_i)
      ret.concat(c.length == 2 ? Range.new(*c).to_a : c)
    }
  end

  ret
end

.stat(sleep = ticks_to_ms_t5) ⇒ Object Also known as: usages

stat(sleep = 1.0 / LinuxStat::Sysconf.sc_clk_tck * 5)

Where sleep is the delay to gather the data.

The minimum possible value at anytime is 1.0 / LinuxStat::Sysconf.sc_clk_tck

This method returns the cpu usage of all threads.

The first one is aggregated CPU usage reported by the Linux kernel.

And the consecutive ones are the real core usages.

For example, on a system with 4 threads:

LinuxStat::CPU.stat

=> {0=>84.38, 1=>100.0, 2=>50.0, 3=>87.5, 4=>87.5}

If the information is not available, it will return an empty Hash



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# File 'lib/linux_stat/cpu.rb', line 23

def stat(sleep = ticks_to_ms_t5)
  return {} unless stat?

  data = IO.readlines('/proc/stat'.freeze).select { |x| x[/^cpu\d*/] }.map! { |x| x.split.map!(&:to_f) }
  sleep(sleep)
  data2 = IO.readlines('/proc/stat'.freeze).select { |x| x[/^cpu\d*/] }.map! { |x| x.split.map!(&:to_f) }

  # On devices like android, the core count can change anytime (hotplugging).
  # I had crashes on Termux.
  # So better just count the min number of CPU and iterate over that
  # If data.length is smaller than data2.length, we don't have enough data to compare.
  dl, d2l = data.length, data2.length
  min = dl > d2l ? d2l : dl

  min.times.reduce({}) do |h, x|
    user, nice, sys, idle, iowait, irq, softirq, steal = *data[x].drop(1)
    user2, nice2, sys2, idle2, iowait2, irq2, softirq2, steal2 = *data2[x].drop(1)

    idle_then, idle_now  = idle + iowait, idle2 + iowait2
    totald = idle_now.+(user2 + nice2 + sys2 + irq2 + softirq2 + steal2) - idle_then.+(user + nice + sys + irq + softirq + steal)

    res = totald.-(idle_now - idle_then).fdiv(totald).abs.*(100)
    res = res.nan? ? 0.0 : res > 100 ? 100.0 : res.round(2)

    h.merge!( x => res )
  end
end

.total_usage(sleep = ticks_to_ms_t5) ⇒ Object Also known as: usage

total_usage(sleep = 1.0 / LinuxStat::Sysconf.sc_clk_tck)

Where sleep is the delay to gather the data.

The minimum possible value at anytime is 1.0 / LinuxStat::Sysconf.sc_clk_tck

This method returns the cpu usage of all threads.

It’s like running LinuxStat::CPU.stat but it’s much more efficient and calculates just the aggregated usage which is available at the top of the /proc/stat file.

If the information is not available, it will return nil.



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# File 'lib/linux_stat/cpu.rb', line 63

def total_usage(sleep = ticks_to_ms_t5)
  return nil unless stat?

  data = IO.foreach('/proc/stat'.freeze).first.split.tap(&:shift).map!(&:to_f)
  sleep(sleep)
  data2 = IO.foreach('/proc/stat'.freeze).first.split.tap(&:shift).map!(&:to_f)

  user, nice, sys, idle, iowait, irq, softirq, steal = *data
  user2, nice2, sys2, idle2, iowait2, irq2, softirq2, steal2 = *data2

  idle_then, idle_now  = idle + iowait, idle2 + iowait2
  totald = idle_now.+(user2 + nice2 + sys2 + irq2 + softirq2 + steal2) - idle_then.+(user + nice + sys + irq + softirq + steal)

  u = totald.-(idle_now - idle_then).fdiv(totald).abs.*(100)
  u > 100 ? 100.0 : u.round(2)
end