Note
Access to this page requires authorization. You can try signing in or changing directories.
Access to this page requires authorization. You can try changing directories.
The MmGetMdlByteCount macro returns the length, in bytes, of the buffer described by the specified MDL.
Syntax
ULONG MmGetMdlByteCount(
[in] PMDL Mdl
);
Parameters
Mdl
A pointer to an MDL structure that describes the layout of a virtual memory buffer in physical memory. For more information, see Using MDLs.
Return value
MmGetMdlByteCount returns the length, in bytes, of the buffer described by Mdl.
Remarks
Macro definition:
#define MmGetMdlByteCount(Mdl) ((Mdl)->ByteCount)
Callers of MmGetMdlByteCount can be running at any IRQL. Usually, callers are running at IRQL <= DISPATCH_LEVEL.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Desktop |
| Header | wdm.h (include Wdm.h, Ntddk.h, Ntifs.h) |
| IRQL | Any level (see Remarks section) |
| DDI compliance rules | MdlAfterReqCompletedIntIoctlA(kmdf), MdlAfterReqCompletedIoctlA(kmdf), MdlAfterReqCompletedReadA(kmdf), MdlAfterReqCompletedWriteA(kmdf) |