Error Code 0x133 DPC Watchdog Violation occurs when a Deferred Procedure Call (DPC) routine runs past its scheduled duration in Windows. This error causes Windows to issue an automatic stop message.
This error is typically due to defective device drivers, though incompatible hardware devices or conflicting software programs can also contribute.
This stop error is typically a driver issue that can be rectified by updating the drivers. To do this, first remove or disable any corrupted drivers and then install the most up-to-date version from the manufacturer’s website.
IRQL_DISPATCH_LEVEL
The IRQL_DISPATCH_LEVEL value is the highest software interrupt level available to system threads. This value is used by the system’s thread scheduler to decide which threads can run on a given processor.
The Windows dispatcher, some kernel-mode support functions and driver functions, DPC routines, IoTimer, Cancel (while holding the cancel spin lock), and CustomTimerDpc all run at IRQL DISPATCH_LEVEL. When a thread runs at this level it has exclusive use of the processor; only hardware interrupts can preempt it.
To maximize system throughput, driver code that executes at IRQL DISPATCH_LEVEL should perform only minimal processing and access data stored in nonpaged memory. Any non-kernel mode support functions must ensure they run in nonpaged memory and do not access paged pool data unsafely.
IRQL_TIMEOUT
DPC (Deferred Procedure Call) is a Windows operating system feature that enables high-priority tasks to defer low-priority processing until later. This deferral of execution helps improve system responsiveness and reduces the total number of events a high-priority task must handle.
When a DPC runs for too long, its watchdog timer triggers an automatic bug check. This can occur due to one long-running DPC or when multiple DPCs collectively consume more time than their allotted duration.
The IRQL_TIMEOUT is an essential timer in Windows. It monitors a series of DPCs and other queued events that could be leading to a bug check or other error.
Its value is most apparent when a bug check reaches the point where it displays the above-mentioned BSOD, but it can also be useful when determining what caused the bug. Often, the most straightforward solution is to try one of many fixes that address DPC_WATCHDOG_VIOLATION’s related issues.
IRQL_TIMER
The IRQL_TIMER is a feature in Windows 7 that continuously checks your system’s hardware to guarantee it functions optimally and alerts you of any problems before they arise. It helps detect and prevent performance bottlenecks in your computer so that you can optimize it for peak efficiency.
The best part is that this feature works while minimizing the strain on your computer’s resources. It’s especially helpful when your machine runs slowly or unstable, since it will ensure you don’t waste time or money trying to fix issues yourself.
There is no one-size-fits-all solution to this issue, so do some research and determine the most appropriate approach for you. It would also be beneficial to keep track of any ad hoc or scheduled tasks you have running as this might help identify any lingering issues and give you a more complete picture of your PC’s state.
IRQL_THREAD
Multitasking operating systems rely heavily on thread scheduling and the interrupt request level (IRQL) of each processor for effective resource allocation. As threads are preempted or interrupts occur, these IRQLs may change due to higher-level user thread preemption or interrupts that raise them higher up the priority chain.
When a thread is interrupted, the system suspends it and runs an interrupt service routine for that device. This routine stops the thread from interrupting, saves any data necessary for further processing, queues a DpcForIsr routine for the processor that the thread was on, and exits.
On a single-processor machine, the interrupt service routine also acquires spin locks to protect shared memory it may access. Once this routine concludes, Processor 0’s DpcForIsr routine begins.
In certain circumstances, driver code running at IRQL PASSIVE_LEVEL must call a system service routine or perform another action that requires higher IRQL. Before calling the routine, the driver code must raise its IRQL to an appropriate level for the action; then it must immediately lower it after finishing with it.
