cbNKPagingPoolSize
Other versions of this page are also available for the following:
.gif "A hyphen indicates that the information in this topic is not relevant for this platform, or that the platform does not support the API that is listed.")
.gif "A checkmark indicates that the information in this topic is relevant for this platform, and that any API listed is also supported on this platform.")
8/28/2008
This variable enables OEMs to limit memory used for paging read-only code or map files by setting the variable to the maximum memory allowed.
This variable is deprecated in Windows Embedded CE in favor of IOCTL_HAL_GET_POOL_PARAMETERS.
Syntax
DWORD cbNKPagingPoolSize;
Parameters
None.
Return Value
None.
Remarks
For All Platorms
The paging pool is a reserved block of RAM that for holding pages of code. If the paging pool is not enabled, the entire RAM on the device is available for paging, which can drastically increase RAM usage. Enabling the paging pool sets aside a limited amount of RAM for paging. The higher the paging pool size, the more RAM is available for paging. This results in fewer page faults, since more code can be held in the paging pool. It is important to determine the right balance between RAM usage for paging pool and paging performance. The following list shows examples of some factors that affect the optimum paging pool size:
- Attributes of OEM components, such as device drivers. Examples of attributes are total size and pageability.
- Total available RAM.
- Processor speed.
- Flash technology, for example, NAND or NOR.
To determine the optimum paging pool size, collect performance data for various paging pool sizes.
For Windows Mobile
The following table shows an example of data that was collected for a reference Windows Mobile 6 Standard platform:
| Paging pool size | 3.0 MB | 3.5 MB | 4 .0 MB | 4.5 MB | 5.0 MB | 6.0 MB |
|---|---|---|---|---|---|---|
Boot time |
38.1 seconds |
37.4 seconds |
34.6 seconds |
31.2 seconds |
29.7 seconds |
28.4 seconds |
Inbox launch |
3.31 seconds |
3.20 seconds |
2.77 seconds |
2.66 seconds |
2.59 seconds |
2.45 seconds |
Contacts launch |
1.72 seconds |
1.62 seconds |
1.41 seconds |
1.20 seconds |
1.16 seconds |
1.15 seconds |
You can graph the performance and paging pool size for each scenario to determine the paging pool size that provides a good balance between RAM used for the paging pool and performance. For the above table, 4.5 MB is the optimum size.**
Requirements
| Header | Developer Implemented |
| Windows Embedded CE | Windows CE 5.0 and later |
See Also
Reference
Concepts
Paging Pool
Obsolete Kernel APIs