DPC Latency

[omin]

Guys, not exactly BSOD, although i do get those every once in a blue moon, less often now since i updated all my drivers.

My problem right now is that my DPC Latency is through the roof, it seems to be because of my Broadcom Netlink Driver. it causes latency as high as 1.3x10^6 microseconds. thats 1.3 full seconds. and i'm running on a relativly high performance machine. do i need to just buy an intel network card? what if that doesn't solve my problem?

 

[TomasD]

Hello,

To properly troubleshoot issues with high/frequent DPCs/IRPs, we require a XPERF trace. Please follow the these steps to generate one:

1. Download Windows Software Development Kit (SDK) for Windows and run the setup.
2. Select Windows Performance Toolkit feature (all the others can be unchecked) and proceed with the download/installation.
3. Once the installation finishes, open an elevated Command Prompt by right-clicking on CMD.EXE shortcut in your start menu and selecting Run As Administrator from the context menu.
4. Type the following command, which will start tracing, in the Command Prompt window you just opened:
   

   xperf -on PROC_THREAD+LOADER+PROFILE+INTERRUPT+DPC+DRIVERS+POWER+IDLE_STATES -stackwalk Profile -BufferSize 1024 -MinBuffers 256 -MaxBuffers 256 -MaxFile 256 -FileMode Circular

   If you see a yellow warning "xperf: warning: This system is not fully configured for x64 stack tracing" after running the above command, please complete these extra steps (otherwise, proceed to the step #5):
   
   Read More:

   1. Run the following command which will stop the tracing:
      

      xperf -stop

   2. Run the following command to enable stack tracing (by disabling Paging Executive):
      

      REG ADD "HKLM\System\CurrentControlSet\Control\Session Manager\Memory Management" -v DisablePagingExecutive -d 0x1 -t REG_DWORD -f

   3. Reboot the computer
   4. Once computer reboots, proceed from the step #3
   If you see a red error "xperf: error: NT Kernel Logger: A device attached to the system is not functioning. (0x1f)" after running the above command, please complete these extra steps (otherwise, proceed to the step #5):
   
   Read More:

   
   

   1. Run the following command to disable Driver Verifier, which causes the above error:
      

      verifier /reset

   2. Reboot the computer
   3. Once computer reboots, proceed from the step #3
5. Perform some activities with your computer for few minutes, making sure the issues you reported are reproduced.
6. Run the following command, which will stop the tracing, in the command prompt window you already have opened:
   

   xperf -stop -d C:\CPU.etl

7. Compress file C:\CPU.etl
8. Upload the compressed file to a file sharing service (e.g. OneDrive or DropBox).
9. Share the download link here.

Thank you.