Edit

READ_AHEAD_PARAMETERS structure (ntifs.h)

  • Article

The READ_AHEAD_PARAMETERS structure contains read-ahead parameters.

Syntax

typedef struct _READ_AHEAD_PARAMETERS {
  CSHORT NodeByteSize;
  ULONG  Granularity;
  ULONG  PipelinedRequestSize;
  ULONG  ReadAheadGrowthPercentage;
} READ_AHEAD_PARAMETERS, *PREAD_AHEAD_PARAMETERS;

Members

NodeByteSize

Size of the node, in bytes.

Granularity

Granularity of read-aheads. This value must be an even power of 2 and greater than, or equal to PAGE_SIZE.

PipelinedRequestSize

The request size to be used when performing pipelined read-aheads, in bytes. Each read-ahead request that is pipelined is broken into smaller PipelinedRequestSize-sized requests. This is typically used to increase the throughput by parallelizing multiple requests instead of one single big one.

For backward compatibility, the Cache Manager will break every read-ahead request into two if this value is zero.

ReadAheadGrowthPercentage

The growth of read ahead as a percentage of the data that has already been ready by the application so far.

Requirements

Requirement Value
Minimum supported client Windows 8
Header ntifs.h

See also

CcReadAhead

CcScheduleReadAhead