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DPC timeout

parsaparsa Member Posts: 46

Hi All,

I am debugging an issue related to DPC timeout. When I run "running -it" command on the dump file, I see the current running thread's stack on most of the processors are waiting for custom shared lock except one thread that is currently holding the shared lock. I assume the "KeAcquireInStackQueuedSpinLock" function raises the IRQL to dispatch and then wait for the lock object in "KxWaitForLockOwnerShip".

This is my question. Raising the IRQL to DISPATCH_LEVEL (internally by the function KeAcquireInStackQueuedSpinLock) and waiting prolonged time for the custom lock will cause the DPC timeout. What is the purpose of "KeYieldProcessorEx" function here. It allows the system to reset DPC or something.

nt!KeYieldProcessorEx+0x2
nt!KxWaitForLockOwnerShip+0x2a
nt!KeAcquireInStackQueuedSpinLock+0x7f

Thanks,
Parsa

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