檢測IDLE處理器的數量ruby

Question

我在4至24個核心的共享Linux機器上工作。爲了讓他們盡其用，我用下面的代碼來檢測處理器的數量從我的Ruby腳本：

return `cat /proc/cpuinfo | grep processor | wc -l`.to_i 

（也許有這樣做的純Ruby的方式？）

但有時一個同事正在使用24個內核中的6個或8個。 （如通過頂部看到的）。如何估算當前未使用的處理器數量，而不會讓任何人感到不安？

謝謝！

Answer 1

您可以使用/proc文件系統中的數據獲取正在運行的進程的CPU關聯信息。下面應該給你的CPU的數量目前正在使用（注：我沒有一臺Linux或Ruby盒旁邊所以這段代碼是未經測試，但你可以得到的想法）：

def processors_in_use 
    procs=[] 
    Dir.glob("/proc/*/stat") {|filename| 
     next if File.directory?(filename) 
     this_proc=[] 
     File.open(filename) {|file| this_proc = file.gets.split.values_at(2,38)} 
     procs << this_proc[1].to_i if this_proc[0]=="R" 
    } 
    procs.uniq.length 
end 

def num_processors 
    IO.readlines("/proc/cpuinfo").delete_if{|x| x.index("processor")==nil}.length 
end 

def num_free_processors 
    num_processors - processors_in_use 
end 

def estimate_free_cpus(count, waittime) 
    results=[] 
    count.times { 
     results << num_free_processors 
     sleep(waittime) 
    } 
    sum=0 
    results.each {|x| sum += x} 
    (sum.to_f/results.length).round 
end 

編輯：我驗證了上面的代碼工作（我使用Ruby 1.9）

Answer 2

啓發BTA的答覆，這是我使用的是什麼：

private 
def YWSystemTools.numberOfActiveProcessors # internal 
    processorForProcs = [] 
    processFiles  = Dir.glob("/proc/*/stat") 
    raise IOError, 'Cannot find /proc/*/stat files. Are you sure this is a linux machine?' if processFiles.empty? 

    processFiles.each do |filename| 
     next if File.directory?(filename) # because /proc/net/stat is a directory 
     next if !File.exists?(filename) # may have disappeared in the meantime 
     this_proc = [] 
     File.open(filename) { |file| this_proc = file.gets.split.values_at(2,38) } 
     processorForProcs << this_proc[1].to_i if this_proc[0]=="R" 
    end 
    processorsInUse = processorForProcs.uniq 
    return(processorsInUse.length) 
end 
public 

def YWSystemTools.numberOfAvailableProcessors 
    numberOfAttempts = 5 
    $log.info("Will determine number of available processors. Wait #{numberOfAttempts.to_s} seconds.") 
    #we estimate 5 times because of local fluctuations in procesor use. Keep minimum. 
    estimationsOfNumberOfActiveProcessors = [] 
    numberOfAttempts.times do 
     estimationsOfNumberOfActiveProcessors << YWSystemTools.numberOfActiveProcessors 
     sleep(1) 
    end 
    numberOfActiveProcessors = estimationsOfNumberOfActiveProcessors.min 
    numberOfTotalProcessors = number_of_processors() 

    raise IOError, '!! # active Processors > # processors' if numberOfActiveProcessors > numberOfTotalProcessors 

    numberOfAvailableProcessors = numberOfTotalProcessors - numberOfActiveProcessors 
    $log.info("#{numberOfAvailableProcessors} out of #{numberOfTotalProcessors} are available!")   
    return(numberOfAvailableProcessors) 
end