How to get sizes of shareable and shared working sets for a process?

Question

I'm trying to get the sizes of the shareable and shared working sets of a process.

This is the code that I use:

internal static unsafe WorkingSetInfo? GetWorkingSetInfo(SafeProcessHandle processHandle)
{
    Settings.Log.Info("Called method: GetWorkingSetInfo");
    uint size = 16;
    void* pointer = Alloc(size);
    int error;
    Settings.Log.Debug("Retrieving info on working set...");
    bool result = QueryWorkingSet(processHandle, pointer, size);
    while (!result)
    {
        error = GetLastPInvokeError();
        if (error is ERROR_BAD_LENGTH)
        {
            size *= 2;
            pointer = Realloc(pointer, size);
            result = QueryWorkingSet(processHandle, pointer, size);
        }
        else
        {
            Settings.Log.DebugFormat("Failed to retrieve info on working set: {0} ({1})", GetLastPInvokeErrorMessage(), error);
            Free(pointer);
            return null;
        }
    }
    PSAPI_WORKING_SET_INFORMATION info = new();
    ulong* dataPointer = (ulong*)pointer;
    info.NumberOfEntries = new(*dataPointer);
    dataPointer += 1;
    info.WorkingSetInfo = new nuint[info.NumberOfEntries];
    for (var i = 0; i < info.NumberOfEntries.ToUInt32(); i++)
    {
        info.WorkingSetInfo[i] = new(*dataPointer);
        dataPointer += 1;
    }
    Free(pointer);
    uint pageSize = GetMemoryPageSize();
    return new(info, pageSize);
}

This code works correctly, but it is also inefficient. Whenever it runs, the CPU usage of my process rises to around 30% (the average is 10% when it does not run).

Is there a way to optimize it, or an alternate way to get the data (I use the QueryWorkingSet function)?

I can use the Native API if there is no alternative.

FSO931s · Accepted Answer · 2024-12-31 16:17:53Z

-1

GetProcessMemoryInfo is well documented making it easier to find support and examples, QueryWorkingSet is less commonly used. GetProcessMemoryInfo provides a broader range of memory-related statistics through the PROCESS_MEMORY_INFO struct while QueryWorkingSet focuses mainly on the basic working set information.

[DllImport("psapi.dll", SetLastError = true)] 
static extern bool GetProcessMemoryInfo(IntPtr processHandle, out 
PROCESS_MEMORY_INFO mem_info, uint size); 
[StructLayout(LayoutKind.Sequential)] 
public struct PROCESS_MEMORY_INFO 
{
    static readonly uint Size = (uint)Marshal.SizeOf<PROCESS_MEMORY_INFO>();
    public uint cb; 
    public uint PageFaultCount; 
    public ulong PeakWorkingSetSize; 
    public ulong WorkingSetSize; 
    public ulong QuotaPeakPagedPoolUsage; 
    public ulong QuotaPagedPoolUsage; 
    public ulong QuotaPeakNonPagedPoolUsage; 
    public ulong QuotaNonPagedPoolUsage; 
    public ulong PagefileUsage; 
    public ulong PeakPagefileUsage; 
    public ulong PrivateUsage;
    public static bool GetProcessInfo(Process proc, out PROCESS_MEMORY_INFO mem_info)
    {
        return GetProcessMemoryInfo(proc.Handle, out mem_info, Size);               
    }
}

Then to use :

static void Main(string[] args)
{
    Process proc = Process.GetCurrentProcess();
    if (PROCESS_MEMORY_INFO.GetProcessInfo(proc, out PROCESS_MEMORY_INFO mem_info))
    {
        ulong workingSetSize = mem_info.WorkingSetSize;
        ulong peakWorkingSetSize = mem_info.PeakWorkingSetSize;
        ulong sharableWorkingSetSize = workingSetSize - mem_info.PrivateUsage;
        Console.WriteLine($"Working Set Size : {workingSetSize}");
        Console.WriteLine($"Peak Working Set Size : {peakWorkingSetSize}");
        Console.WriteLine($"Shareable Working Set Size : {sharableWorkingSetSize}");
    }
}

edited Dec 31, 2024 at 16:17

answered Dec 31, 2024 at 14:49

FSO931s

1644 silver badges14 bronze badges

Sign up to request clarification or add additional context in comments.

3 Comments

IInspectable Dec 31, 2024 at 15:28

A quality answer must identify the core issue and explain why and how the proposed solution addresses it.

IInspectable Dec 31, 2024 at 16:33

The update merely provides unfounded opinion and answers a question that hasn't been asked.

dt_overflow Dec 31, 2024 at 19:38

The GetProcessMemoryInfo function provides the total size of the working set, I need to know the shareable and the shared portion of it. As far as I could find. this information is given only by QueryWorkingSet or NtQueryVirtualMemory (the output of which is the same).

Collectives™ on Stack Overflow

How to get sizes of shareable and shared working sets for a process?

1 Answer 1

3 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

3 Comments

Your Answer

Sign up or log in

Post as a guest

Related