DPC_WATCHDOG_VIOLATION (133)

Question

hi,
I ran the CHAOS test on our driver and get DPC_WATCHDOG_VIOLATION (133).
in the stack I see tat last try is to enqueue a request to the IoDefaultQueue (from EvtIoIncallerContext):
      nt!VfIrpDatabaseCheckExFreePool+0x7d
                                        nt!VerifierExFreePoolWithTag+0x1e
                                        Wdf01000!FxTagTracker::UpdateTagHistory+0x1ae
                                        Wdf01000!FxObject::Release+0x41e3e
                                        Wdf01000!FxPkgIo::EnqueueRequest+0x26a
                                        Wdf01000!imp_WdfDeviceEnqueueRequest+0xc9
                                        myDriver!WdfDeviceEnqueueRequest+0x3d
                                        myDriver!EvtIoInCallerContext+0x551
is there any internal spinlock used by the framework to insert requests to queue? if so, how can I know which spinlocks are used and who catch them? Is there an option that another callback use the internal spinlock and for that, the enqueue is stuck?
we have in our default queue only one callback: EvtIoDefault and our queue dispach its requests as WdfIoQueueDispatchParellel, so I assume that the EvtIoDefault don't cause the enqueue to be stucked.
Any guidance how to progress with this BSOD will be very appreciated.
thanks,
Shosho
EvtIoDefault

Answer 1

The frame Wdf01000!FxTagTracker::UpdateTagHistory in the call stack you pasted, suggests that you have "TrackHandles" verification enabled for the driver. Tracking reference counts on WDF objects may add significant over head,
especially if enabled for all or multiple WDF object types and while running stress (CHAOS test). I'd suggest you try running the test with handle tracking disabled.
The use of TrackHandles is documented here:
https://msdn.microsoft.com/en-us/library/windows/hardware/ff544573(v=vs.85).aspx
This blog post also has useful information relevant to this bug check code:
http://blogs.msdn.com/b/ntdebugging/archive/2012/12/07/determining-the-source-of-bug-check-0x133-dpc-watchdog-violation-errors-on-windows-server-2012.aspx