0

While studying Deferred Procedure Calls I came to some properties/data I could not find any information about on the web.

Using WMI I can read a lot of processor data, including DPC data.

Many properties of the Win32_PerfRawData_Counters_ProcessorInformation WMI class are self-explanatory, for example InterruptsPerSec or PercentInterruptTime.

One of the properties is called DPCRate.

Powershell code to get the value:

Get-CimInstance -Class Win32_PerfRawData_Counters_ProcessorInformation | Format-Table -Property DPCRate

On my system the value of the DPCRate varies between 40 and 70.

What is the meaning of this value? What does it measure? I could not find anything in Microsoft's WMI documentation.

Casady
  • 1,426
  • 3
  • 19
  • 39
  • Google finds: *DPC Rate is the rate at which deferred procedure calls (DPCs) were added to the processors DPC queues between the timer ticks of the processor clock. DPCs are interrupts that run at alower priority than standard interrupts. Each processor has its own DPC queue. This counter measures the rate that DPCs were added to the queue, not the number of DPCs in the queue. This counter displays the last observed value only; it is not an average* – Jonathan Potter Apr 28 '20 at 23:51
  • Thanks. My error was to search for the actual property name "DPCRate" instead of "DPC Rate". – Casady Apr 29 '20 at 14:31

1 Answers1

2

DPCRate :

DPC Rate is the rate at which deferred procedure calls (DPCs) were added to the processors DPC queues between the timer ticks of the processor clock. DPCs are interrupts that run at alower priority than standard interrupts. Each processor has its own DPC queue. This counter measures the rate that DPCs were added to the queue, not the number of DPCs in the queue. This counter displays the last observed value only; it is not an average.

Refer to The WMI Explorer Tool for getting a PowerShell WMI Browser tool for querying WMI class and its properties description.

Update:

enter image description here

Rita Han
  • 9,574
  • 1
  • 11
  • 24
  • I have tried WMI Explorer 2.0 yesterday, but a recursive search for the Win32_PerfRawData_Counters_ProcessorInformation class in the root node doesn't produce any results, nor does a recursive search for a DPCRate property. – Casady Apr 29 '20 at 14:27
  • @Casady I update my answer with steps of how to find the property. – Rita Han Apr 30 '20 at 02:24
  • Thanks. This has worked. The problem is the first link you have posted ends up in a github download link to a completely different WMI Explorer where Win32_PerfRawData_Counters_ProcessorInformation is missing. The correct link to download the Powershell WMI Explorer tool is: https://powershell.org/2013/03/wmi-explorer/ – Casady May 01 '20 at 08:54