如何限制進程的CPU使用率

Question

我想創建一個程序，即使在計算機處於空閑狀態時也可以限制進程的CPU使用率。我已經制定了一個設置進程優先級的程序，但如果計算機空閑，則cpu使用率可以達到95％。 該過程包含“元素”是我想要限制的過程

    private static readonly string[] RestrictedProcess = new[] { "element" }; 
    static void ProcessChecker(object o)
    {
        List<Process> resProc = new List<Process>();
        foreach(Process p in Process.GetProcesses())
        {
            string s = p.ProcessName;
            foreach(string rp in RestrictedProcess)
            {
                s = s.ToLower();
                if (s.Contains(rp))
                    resProc.Add(p);
            }
        }

        foreach(Process p in resProc)
        {
            p.PriorityBoostEnabled = false;
            p.PriorityClass = ProcessPriorityClass.Idle;
            p.MaxWorkingSet = new IntPtr(20000000);
        }

        SetPowerConfig(resProc.Count > 0 ? PowerOption.GreenComputing : PowerOption.Balanced);
    }

提前致謝...

Answer 1

如果您想要限制的程序不是您的，有幾個選項：

• 將進程優先級設置為Idle並且不限制CPU使用率 ，因為在任何情況下都應盡可能多地使用CPU。 如果有一些有用的事情可以讓你的CPU一直運行100％。 如果優先級idle ，則如果另一個程序需要CPU，則此特定進程的CPU使用率將降低。
• 如果您的系統是多核或多CPU，則可能需要設置處理器關聯 。 這將告訴您的程序只使用您希望他使用的處理器。 例如，如果您的程序是多線程的並且能夠消耗兩個CPU的100％，那么將其親和性設置為僅使用一個CPU。 他的使用率僅為50％。
• 最糟糕的選項，但實際上你可以在網上找到90％的“CPU限制器程序” ：測量進程的CPU使用率並定期暫停和恢復它，直到它的CPU使用率達到你想要的值。

要暫停/恢復不屬於您的進程，您必須使用P / Invoke（這需要有權訪問該進程，因此如果您是Windows Vista或更高版本，請注意UAC以獲取管理員權限）：

/// <summary>
/// The process-specific access rights.
/// </summary>
[Flags]
public enum ProcessAccess : uint
{
    /// <summary>
    /// Required to terminate a process using TerminateProcess.
    /// </summary>
    Terminate = 0x1,

    /// <summary>
    /// Required to create a thread.
    /// </summary>
    CreateThread = 0x2,

    /// <summary>
    /// Undocumented.
    /// </summary>
    SetSessionId = 0x4,

    /// <summary>
    /// Required to perform an operation on the address space of a process (see VirtualProtectEx and WriteProcessMemory).
    /// </summary>
    VmOperation = 0x8,

    /// <summary>
    /// Required to read memory in a process using ReadProcessMemory.
    /// </summary>
    VmRead = 0x10,

    /// <summary>
    /// Required to write to memory in a process using WriteProcessMemory.
    /// </summary>
    VmWrite = 0x20,

    /// <summary>
    /// Required to duplicate a handle using DuplicateHandle.
    /// </summary>
    DupHandle = 0x40,

    /// <summary>
    /// Required to create a process.
    /// </summary>
    CreateProcess = 0x80,

    /// <summary>
    /// Required to set memory limits using SetProcessWorkingSetSize.
    /// </summary>
    SetQuota = 0x100,

    /// <summary>
    /// Required to set certain information about a process, such as its priority class (see SetPriorityClass).
    /// </summary>
    SetInformation = 0x200,

    /// <summary>
    /// Required to retrieve certain information about a process, such as its token, exit code, and priority class (see OpenProcessToken, GetExitCodeProcess, GetPriorityClass, and IsProcessInJob).
    /// </summary>
    QueryInformation = 0x400,

    /// <summary>
    /// Undocumented.
    /// </summary>
    SetPort = 0x800,

    /// <summary>
    /// Required to suspend or resume a process.
    /// </summary>
    SuspendResume = 0x800,

    /// <summary>
    /// Required to retrieve certain information about a process (see QueryFullProcessImageName). A handle that has the PROCESS_QUERY_INFORMATION access right is automatically granted PROCESS_QUERY_LIMITED_INFORMATION.
    /// </summary>
    QueryLimitedInformation = 0x1000,

    /// <summary>
    /// Required to wait for the process to terminate using the wait functions.
    /// </summary>
    Synchronize = 0x100000
}

[DllImport("ntdll.dll")]
internal static extern uint NtResumeProcess([In] IntPtr processHandle);

[DllImport("ntdll.dll")]
internal static extern uint NtSuspendProcess([In] IntPtr processHandle);

[DllImport("kernel32.dll", SetLastError = true)]
internal static extern IntPtr OpenProcess(
    ProcessAccess desiredAccess,
    bool inheritHandle,
    int processId);

[DllImport("kernel32.dll", SetLastError = true)]
[return: MarshalAs(UnmanagedType.Bool)]
internal static extern bool CloseHandle([In] IntPtr handle);

public static void SuspendProcess(int processId)
{
    IntPtr hProc = IntPtr.Zero;
    try
    {
        // Gets the handle to the Process
        hProc = OpenProcess(ProcessAccess.SuspendResume, false, processId);

        if (hProc != IntPtr.Zero)
        {
            NtSuspendProcess(hProc);
        }
    }
    finally
    {
        // Don't forget to close handle you created.
        if (hProc != IntPtr.Zero)
        {
            CloseHandle(hProc);
        }
    }
}

Answer 2

我不知道C＃的確切命令，但它會將控制權交還給操作系統。 我認為在C ++中，它可能會延遲或睡眠。 因此，C＃中的等效調用將延遲代碼並將循環返回給操作系統。