Windows – How to know the CPU and memory usage of a process with WMI

windowswmi

I am using a wmi and python in order to track the behavior of the process running on my machine.

from win32com.client import GetObject
wmi = GetObject('winmgmts:')
processes = wmi.InstancesOf('Win32_Process')

for process in processes:
    print process.ProcessId, process.Name

The Win32_Process has a lot of information but I don't see anything for tracking the CPU consumption. The window Task Monitor is showing this info so I think it is possible to get it.

I thought that the WorkingSetSize property is giving the memory consumption of the process but I can see different value from what is given by TaskMonitor.

How to get these 2 values for a given process?

Update:
Task Monitor shows the PrivateWorkingSetSize which seems to be not available with the Win32_Process. What is the difference betwen WorkingSetSize and PrivateWorkingSetSize?

Best Answer

I'm pretty sure you want the WMI perf classes Win32_PerfFormattedData_PerfProc_Process or Win32_PerfRawData_PerfProc_Process

E.g. their properties PercentProcessorTime and WorkingSet

Note that the Perf classes take a bit effort to understand.

There are gotchas with the Formatted versions (See Hey, Scripting Guy! article Why Does My Performance Monitoring Script Keep Returning the Same Incorrect Values?)
And the Raw Data classes need care to translate the "CounterType" into the right math formula to use to calculate the values based on the raw data. See How's My Driving? Monitoring Performance Using WMI for a starting place.

But those WMI classes should give you all the info you're looking for.

Related Solutions

Windows – Tracking CPU and Memory usage per process

Just type perfmon into Start > Run and press enter. When the Performance window is open, click on the + sign to add new counters to the graph. The counters are different aspects of how your PC works and are grouped by similarity into groups called "Performance Object".

For your questions, you can choose the "Process", "Memory" and "Processor" performance objects. You then can see these counters in real time

You can also specify the utility to save the performance data for your inspection later. To do this, select "Performance Logs and Alerts" in the left-hand panel. (It's right under the System Monitor console which provides us with the above mentioned counters. If it is not there, click "File" > "Add/remove snap-in", click Add and select "Performance Logs and Alerts" in the list".) From the "Performance Logs and Alerts", create a new monitoring configuration under "Counter Logs". Then you can add the counters, specify the sampling rate, the log format (binary or plain text) and log location.

Windows – How is CPU usage computed

I am not 100% sure what is uses, but I think you are a bit off on the CPU calculation.

I believe they are doing something like.

Process A CPU Usage = (Cycles for A over last X seconds)/(Total cycles for last X seconds)

I believe it is tied to the "update interval" set in task manager.

While doing a bit of research for you though I found this MSDN article that shows a microsoft recommended way of calculating the CPU time of a set of instructions, this might point you a bit towards their calculation as well.

Best Answer

Related Solutions

Windows – Tracking CPU and Memory usage per process

Windows – How is CPU usage computed

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