Need to allocate a big Nonpaged memory

NTDEV
1

Hello,
I need to define a large Nonpaged shared memory (200MB).
I have 1GB memory install on my machine (XP Professional)

The allocation fails.

I also tried to play with the registry
HKLM\SYSTEM\CurrentControlSet\Control\SessionManager\MemoryManagement\NonPag
edPoolSize

and it does not help.

OS.

2

You’re not going to find enough free contiguous VM in kernel space for a
range of this size; a good driver shouldn’t keep more than a megabyte or
two of non-paged memory allocated for the long-term. I suggest you find
another solution.

osmlist wrote:

Hello,
I need to define a large Nonpaged shared memory (200MB).
I have 1GB memory install on my machine (XP Professional)

The allocation fails.

I also tried to play with the registry
HKLM\SYSTEM\CurrentControlSet\Control\SessionManager\MemoryManagement\NonPag
edPoolSize

and it does not help.

OS.

–
Nick Ryan (MVP for DDK)

3

The knowledge base article Q126402 seems to be saying that the maximum
non-paged pool size is 128MB. This article contains lots of information
about how the maximum allowed size is calculated.

The previous poster’s suggestion that you find another design is also a
valid suggestion. Of course, you may want this for some non-production
environment where abuse of the kernel is ok, but the KB article seems to
indicate that it may be impossible even then.

Nick Ryan wrote:

You’re not going to find enough free contiguous VM in kernel space for a
range of this size; a good driver shouldn’t keep more than a megabyte or
two of non-paged memory allocated for the long-term. I suggest you find
another solution.

osmlist wrote:

> Hello,
> I need to define a large Nonpaged shared memory (200MB).
> I have 1GB memory install on my machine (XP Professional)
>
> The allocation fails.
>
> I also tried to play with the registry
> HKLM\SYSTEM\CurrentControlSet\Control\SessionManager\MemoryManagement\NonPag
>
> edPoolSize
>
> and it does not help.
>
> OS.
>
>

–
…/ray..

4

One option is to reserve memory by using /MAXMEM option in boot.ini.
You have to be careful with memory that may be reserved for crappy
display hardware which may occupy last few Mbytes of your dram.

ned

osmlist wrote:

Hello,
I need to define a large Nonpaged shared memory (200MB).
I have 1GB memory install on my machine (XP Professional)

The allocation fails.

I also tried to play with the registry
HKLM\SYSTEM\CurrentControlSet\Control\SessionManager\MemoryManagement\NonPag
edPoolSize

and it does not help.

OS.

Questions? First check the Kernel Driver FAQ at http://www.osronline.com/article.cfm?id=256

You are currently subscribed to ntdev as: xxxxx@colorbus.com.au
To unsubscribe send a blank email to xxxxx@lists.osr.com