Re: SEC_COMMIT usefulness in CreateFileMapping API



Windows CE does not use a page file, which means that non file-backed data (such as a memory mapped file without a base file in the filesystem) will never be paged out to disk.

See http://blogs.msdn.com/ce_base/archive/2008/01/19/Paging-and-the-Windows-CE-Paging-Pool.aspx


Good luck,

Michel Verhagen, eMVP
Check out my blog: http://GuruCE.com/blog

GuruCE
Microsoft Embedded Partner
http://GuruCE.com
Consultancy, training and development services.

curious1 wrote:
Hi All,

I am trying to understand importance of SEC_COMMIT section attibute when using CreateFileMapping API to share mapped file between two processes.

I am using hFile as INVALID_HANDLE_VALUE. which means no file is created in filesystem, so file will will be mapped into memory directly. How can I prevent this file frombeing paged out of memory and in case it is paged out, will the OS save this somewhere on filesystem ? How will this work if I have not given a valid file handle (basically no file exist in filesystem) ?

please help me understand this. I truly appreciate your time ...

thanks !

HANDLE CreateFileMapping(
HANDLE hFile, LPSECURITY_ATTRIBUTES lpFileMappingAttributes, DWORD flProtect, DWORD dwMaximumSizeHigh, DWORD dwMaximumSizeLow, LPCTSTR lpName );

.



Relevant Pages

  • AIX 5.2 maxperm & Oracle
    ... maxperm was set to 63%, ... large volumes of data IO going through the AIX filesystem cache). ... for memory with filesystem cache. ...
    (comp.unix.aix)
  • Re: compiling root filesystem into kernel (preferably tmpfs root filesystem)
    ... compiling root filesystem into kernel ... (read only roots backed by media other than memory). ... Next, DO NOT compress the image with mkuzip, instead do: ...
    (freebsd-hackers)
  • Re: [00/17] Large Blocksize Support V3
    ... to lock the filesystem block and prevent any updates to it, ... get 128 pages into a bio so all we've done churned some in memory ... I/O no faster than the current code. ... We can't use buffer heads - they can only point ...
    (Linux-Kernel)
  • Re: RFC: CONFIG_PAGE_SHIFT (aka software PAGE_SIZE)
    ... but now we waste more memory on small files.... ... allowing us to increase the fundamental block size of the filesystem. ... _whole_ kernel faster. ... If I want a inode cache, it always needs to be 8k based. ...
    (Linux-Kernel)
  • Re: compiling root filesystem into kernel (preferably tmpfs root filesystem)
    ... the statically compiled-in root file system. ... you can compile a fs image into the kernel. ... binaries being on a read only filesystem backed by the install DVD?) ... (read only roots backed by media other than memory). ...
    (freebsd-hackers)