CcUnmapFileOffsetFromSystemCache routine

The CcUnmapFileOffsetFromSystemCache routine removes a portion of a cached file from the system cache.

Syntax


VOID CcUnmapFileOffsetFromSystemCache(
  _In_ PFILE_OBJECT   FileObject,
  _In_ PLARGE_INTEGER FileOffset,
  _In_ ULONG          Length,
  _In_ ULONG          Flags
);

Parameters

FileObject [in]

Pointer to a file object for the cached file whose cache memory will be unmapped.

FileOffset [in]

Pointer to the file location to begin unmapping from the system cache.

Length [in]

The length of the portion of the file to unmap from the cache. If Length is 0, then the remaining portion of the memory section for the file, beginning at FileOffset, is unmapped.

Flags [in]

Not used. Set Flags to 0.

Return value

None

Remarks

Setting both FileOffset and Length to 0 will cause CcUnmapFileOffsetFromSystemCache to unmap the entire memory section for a cached file.

CcUnmapFileOffsetFromSystemCache allows file system drivers to reduce cache utilization when a large number of file portions are held in the system cache.

Requirements

Target platform

Universal

Version

Available in Windows 8 and later versions of Windows.

Header

Ntifs.h (include Ntifs.h)

Library

NtosKrnl.lib

DLL

NtosKrnl.exe

 

 

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