SYSTEM_DPC_BEHAVIOR_INFORMATION

The SYSTEM_DPC_BEHAVIOR_INFORMATION structure is produced as output or expected as input by the functions

• ZwQuerySystemInformation or NtQuerySystemInformation;
• ZwSetSystemInformation or NtSetSystemInformation;

respectively, when given the information class SystemDpcBehaviorInformation (0x18).

Documentation Status

The SYSTEM_DPC_BEHAVIOR_INFORMATION structure is not documented.

Microsoft does publish the practical equivalent of a C-language definition as type information in public symbol files, though not for the kernel, where the structure is prepared, nor even for low-level user-mode DLLs that interpret the structure, but for various higher-level user-mode DLLs such as URLMON.DLL and only then starting with version 6.2.

Two earlier disclosures of type information are known, though not in symbol files but in statically linked libraries: GDISRVL.LIB from the Device Driver Kit (DDK) for Windows NT 3.51; and SHELL32.LIB from the DDK for Windows NT 4.0.

Layout

The SYSTEM_DPC_BEHAVIOR_INFORMATION is 0x14 bytes in both 32-bit and 64-bit Windows.

ULONG Spare;

ULONG DpcQueueDepth;

ULONG MinimumDpcRate;

ULONG AdjustDpcThreshold;

ULONG IdealDpcRate;