MmAllocateContiguousMemory on NT

NTDEV
1

Hello,

i need continuous memory without caching on Windows NT 4. On Windows 2000
there is a function called MmAllocateContiguousMemorySpecifyCache, but this
function does not exist on NT 4. Is there any possiblity to get non-cached
continuous memory on NT 4 ?

Thanks in advance,
A. Roth

2

MmAllocateNonCachedMemory() . What I dont know for sure, is that if this
routine makes any attmept to guarantee contigous memory. IIRC, it does not.

Regards, Dan

----- Original Message -----
From: “Andreas Roth”
To: “NT Developers Interest List”
Sent: Tuesday, August 13, 2002 4:56 PM
Subject: [ntdev] MmAllocateContiguousMemory on NT

> Hello,
>
> i need continuous memory without caching on Windows NT 4. On Windows 2000
> there is a function called MmAllocateContiguousMemorySpecifyCache, but
this
> function does not exist on NT 4. Is there any possiblity to get non-cached
> continuous memory on NT 4 ?
>
> Thanks in advance,
> A. Roth
>
>
>
>
> —
> You are currently subscribed to ntdev as: xxxxx@rdsor.ro
> To unsubscribe send a blank email to %%email.unsub%%
>

3

I tested it and it seem that it allocates cached memory.

A. Roth

-----Original Message-----
From: xxxxx@lists.osr.com
[mailto:xxxxx@lists.osr.com]On Behalf Of Dan Partelly
Sent: Tuesday, August 13, 2002 3:55 PM
To: NT Developers Interest List
Subject: [ntdev] Re: MmAllocateContiguousMemory on NT

MmAllocateNonCachedMemory() . What I dont know for sure, is that if this
routine makes any attmept to guarantee contigous memory. IIRC, it does not.

Regards, Dan

----- Original Message -----
From: “Andreas Roth”
To: “NT Developers Interest List”
Sent: Tuesday, August 13, 2002 4:56 PM
Subject: [ntdev] MmAllocateContiguousMemory on NT

> Hello,
>
> i need continuous memory without caching on Windows NT 4. On Windows 2000
> there is a function called MmAllocateContiguousMemorySpecifyCache, but
this
> function does not exist on NT 4. Is there any possiblity to get non-cached
> continuous memory on NT 4 ?
>
> Thanks in advance,
> A. Roth
>
>
>
>
> —
> You are currently subscribed to ntdev as: xxxxx@rdsor.ro
> To unsubscribe send a blank email to %%email.unsub%%
>

—
You are currently subscribed to ntdev as: xxxxx@arsoft-online.com
To unsubscribe send a blank email to %%email.unsub%%

4

Only Seems ? How did you tested it ? Your safest bet to check for this is to
dump the PTE using !pte and check for CacheDisable bit status.

Dan

----- Original Message -----
From: “Andreas Roth”
To: “NT Developers Interest List”
Sent: Tuesday, August 13, 2002 5:49 PM
Subject: [ntdev] Re: MmAllocateContiguousMemory on NT

> I tested it and it seem that it allocates cached memory.
>
> A. Roth
>
> -----Original Message-----
> From: xxxxx@lists.osr.com
> [mailto:xxxxx@lists.osr.com]On Behalf Of Dan Partelly
> Sent: Tuesday, August 13, 2002 3:55 PM
> To: NT Developers Interest List
> Subject: [ntdev] Re: MmAllocateContiguousMemory on NT
>
>
> MmAllocateNonCachedMemory() . What I dont know for sure, is that if this
> routine makes any attmept to guarantee contigous memory. IIRC, it does
not.
>
> Regards, Dan
>
>
> ----- Original Message -----
> From: “Andreas Roth”
> To: “NT Developers Interest List”
> Sent: Tuesday, August 13, 2002 4:56 PM
> Subject: [ntdev] MmAllocateContiguousMemory on NT
>
>
> > Hello,
> >
> > i need continuous memory without caching on Windows NT 4. On Windows
2000
> > there is a function called MmAllocateContiguousMemorySpecifyCache, but
> this
> > function does not exist on NT 4. Is there any possiblity to get
non-cached
> > continuous memory on NT 4 ?
> >
> > Thanks in advance,
> > A. Roth
> >
> >
> >
> >
> > —
> > You are currently subscribed to ntdev as: xxxxx@rdsor.ro
> > To unsubscribe send a blank email to %%email.unsub%%
> >
>
>
>
> —
> You are currently subscribed to ntdev as: xxxxx@arsoft-online.com
> To unsubscribe send a blank email to %%email.unsub%%
>
>
>
> —
> You are currently subscribed to ntdev as: xxxxx@rdsor.ro
> To unsubscribe send a blank email to %%email.unsub%%
>

5

> function does not exist on NT 4. Is there any possiblity to get
non-cached

continuous memory on NT 4 ?

x86 platform maintains PCI DMA/cache coherency automatically. So, why
you need noncached memory?

I would suggest using (Hal)AllocateCommonBuffer for such allocations.
This is a way to go for DMA.

Max