Question

我想获得Ubuntu中一个进程的CPU和内存利用率。我的问题是这些数字低于0.01％。那么如何获得非常详细的数字，例如0.00123％？

Answer 1

这是我编写的一个小型bash脚本，用于获取进程的详细CPU使用情况。

#!/bin/bash

# A simple script that prints the CPU usage
# of a process with ten (10) decimals points
# (based on this https://stackoverflow.com/a/1424556/1930099).
#
# Usage: bash cpu-usage.bsh {PID_NUM}

PID=$1 # The process id
CLK_TCK=$(getconf CLK_TCK) # CPU clock ticks
CORES=$(nproc) # Number of CPU cores

main() {
    while true; do    
        local total_time_before=$(get_cpu_total_times)
        local stats_before=$(get_process_stats)
        local utime_before=$(echo $stats_before | cut -d " " -f14) # Amount of time that this process has been scheduled in user mode
        local stime_before=$(echo $stats_before | cut -d " " -f15) # Amount of time that this process has been scheduled in kernel mode

        sleep 1

        local total_time_after=$(get_cpu_total_times)
        local stats_after=$(get_process_stats)
        local utime_after=$(echo $stats_after | cut -d " " -f14)
        local stime_after=$(echo $stats_after | cut -d " " -f15)

        local user_util=$(echo "scale=10; $CORES * $CLK_TCK * ($utime_after - $utime_before) / ($total_time_after - $total_time_before)" |  bc -l | awk '{printf "%.10f\n", $0}')
        local sys_util=$(echo "scale=10; $CORES * $CLK_TCK * ($stime_after - $stime_before) / ($total_time_after - $total_time_before)" |  bc -l | awk '{printf "%.10f\n", $0}')

        echo -ne "User Utilization: $user_util % | Kernel utilization: $sys_util % \r"
    done    
}

get_cpu_total_times() {
    # The amount of time, measured in units of USER_HZ, 
    # that the system or the specific CPU spent in various states.
    local cpu_times=$(cat /proc/stat | head -n 1) # This tells you the cumulative CPU time that's been used in various categories
    local cpu_times_arr=($cpu_times)

    local user=${cpu_times_arr[1]} # Time spent in user mode
    local nice=${cpu_times_arr[2]} # Time spent in user mode with low priority (nice)
    local system=${cpu_times_arr[3]} # Time spent in system mode
    local idle=${cpu_times_arr[4]} # Time spent in the idle task

    echo $(($user + $nice + $system + $idle))
}

# Status information about the process
get_process_stats() {
    local stats=$(cat "/proc/${PID}/stat") # A pseudo-file which implements an interface to retrieve process execution statistics from the kernel 
    echo "$stats"
}

main "$@"

您必须阅读proc的手册页才能了解其背后的逻辑。该脚本基于answer中的@caf。鉴于此，实现进程的内存利用率也不会那么困难。

在proc的手册页中检查/proc/[pid]/statm

如何获得进程的详细CPU和内存利用率？

1 个答案: