Module: LinuxStat::CPU

Defined in:
lib/linux_stat/cpu.rb

Overview

Shows various CPU related information of the current system.

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 294

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.store(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 89

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 106

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 200

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.store(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 272

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.store(id, IO.read(file).tap(&:strip!)) if File.readable?(file)
	}

	h
end

.hyperthreaded_core_list ⇒ Object Also known as: hyperthreaded_cores

Returns the number of physical cores on the system.

The return value is an Array of Integers. Each number denoting the hyperthreaded processor number. You can later use this to schedule tasks or something else (not provided by LinuxStat).

However, if the information isn’t available on /sys/devices/system/cpu*/topology/thread_siblings_list, it will return an empty Array.



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# File 'lib/linux_stat/cpu.rb', line 354

def hyperthreaded_core_list
	hyperthreaded = {}

	entries = Dir.entries('/sys/devices/system/cpu/'.freeze)
	entries.delete(?..freeze)
	entries.delete('..'.freeze)

	entries.each do |x|
		if x[0..2] == 'cpu'.freeze && LinuxStat::Misc.integer?(x[3..-1])
			file = "/sys/devices/system/cpu/#{x}/topology/thread_siblings_list"
			next unless File.readable?(file)

			data = IO.read(file)
			data.strip!

			val = data.split(?,.freeze).map(&:to_i)
			val.shift

			# Add items has for fast lookup to get rid of duplicate items.
			val.each { |x| hyperthreaded.store(x, nil) unless hyperthreaded.key?(x) }
		end
	end

	hyperthreaded.keys
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 248

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.store(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 226

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.store(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 187

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 166

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 135

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

.physical_core_list ⇒ Object Also known as: physical_cores

Returns the number of physical cores on the system.

The return value is an Array of Integers. Each number denoting the physical processor number. You can later use this to schedule tasks or something else (not provided by LinuxStat).

However, if the information isn’t available on /sys/devices/system/cpu*/topology/thread_siblings_list, it will return an empty Array.



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# File 'lib/linux_stat/cpu.rb', line 314

def physical_core_list
	physical_cores = []
	hyperthreaded = {}

	entries = Dir.entries('/sys/devices/system/cpu/'.freeze)
	entries.delete(?..freeze)
	entries.delete('..'.freeze)

	entries.each do |x|
		if x[0..2] == 'cpu'.freeze && LinuxStat::Misc.integer?(x[3..-1])
			file = "/sys/devices/system/cpu/#{x}/topology/thread_siblings_list"
			next unless File.readable?(file)

			data = IO.read(file)
			data.strip!

			val = data.split(?,.freeze).map(&:to_i)
			val.shift

			# Add items has for fast lookup.
			# This hash includes all hyper threaded cores that doesn't map to anything.
			# But this hash has the purpose to look up for items and not include in the list of physical_cores
			# This is just an array, but can look for keys in O(1), so it's faster than ary.find() { ... }.
			val.each { |x| hyperthreaded.store(x, nil) }

			key = x[3..-1].to_i
			physical_cores << key unless hyperthreaded.key?(key)
		end
	end

	physical_cores
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 25

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.store(x, res)
		h
	end
end

.times ⇒ Object 



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# File 'lib/linux_stat/cpu.rb', line 213

def times
	LinuxStat::ProcFS.cpu_times
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 66

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