StorPortQueryDpcWatchdogInformation function (storport.h)

StorPortQueryDpcWatchdogInformation queries DPC watchdog timer values for the current processor.

Syntax

ULONG StorPortQueryDpcWatchdogInformation(
  [in]  PVOID                          HwDeviceExtension,
  [out] PSTOR_DPC_WATCHDOG_INFORMATION DpcWatchdogInformation
);

Parameters

[in] HwDeviceExtension

A pointer to the miniport's device extension.

[out] DpcWatchdogInformation

Pointer to a STOR_DPC_WATCHDOG_INFORMATION structure in which the DPC watchdog information will be written.

Return value

This function returns one of the following status codes.

Remarks

A miniport can call StorPortQueryDpcWatchdogInformation at IRQL=DISPATCH_LEVEL to determine the amount of time that remains before a deferred procedure call (DPC) time-out occurs. The operating system implements a DPC watchdog timer to detect when a single DPC routine runs for too long, or when a series of queued DPC routines runs back-to-back for too long. If DPC time-out errors are enabled, and if either a DPC routine exceeds the time limit for a single routine, or a series of DPC routines exceeds the aggregate time limit, a DPC_WATCHDOG_VIOLATION (0x133) bug check occurs.

StorPortQueryDpcWatchdogInformation must be called while a DPC is running or invoked at IRQL= DISPATCH_LEVEL or higher on the current processor. Otherwise, the call fails and returns STOR_STATUS_UNSUCCESSFUL.

DPC routines should run only for brief periods, and should delegate as much processing as possible to worker threads. To avoid degrading system responsiveness, a typical DPC routine should run for no more than 100 microseconds each time it is called. For general information, see Guidelines for Writing DPC Routines.

Requirements

See also

STOR_DPC_WATCHDOG_INFORMATION