DeferredProcedureCallPKDPC

DeferredProcedureCallPKDPC refers to a mechanism within the Windows operating system used for deferring the execution of certain routines until interrupt level 2 is reached. This is a crucial part of the operating system's interrupt handling and task scheduling. PKDPC stands for "Procedure Call Dispatcher".

When a high-priority task or an event occurs that requires immediate attention but cannot be handled directly at the current interrupt level, the system can queue a deferred procedure call. This allows the current, higher-priority interrupt service routine to complete without being significantly delayed. Once the current routine finishes and the system's interrupt priority drops to a level that can accommodate the queued call, the DeferredProcedureCallPKDPC routine is executed.

This mechanism is vital for maintaining system responsiveness and stability. It prevents lower-priority tasks from blocking critical operations and ensures that time-sensitive events are processed efficiently. By deferring less critical operations, the operating system can prioritize and handle urgent interrupts first, leading to a smoother user experience and more reliable system performance. The system uses a queue to manage multiple deferred procedure calls, processing them in the order they were queued or based on specific system priorities.