[Celinux-dev] big physical-continuous memory allocation

[Gross, Mark]

>-----Original Message-----
>From: celinux-dev-bounces at tree.celinuxforum.org [mailto:celinux-dev-
>bounces at tree.celinuxforum.org] On Behalf Of Stanley Cai
>Sent: Sunday, August 19, 2007 7:56 AM
>To: celinux-dev at tree.celinuxforum.org
>Subject: [Celinux-dev] big physical-continuous memory allocation
>
>Hi,
>
>Our camera application needs allocate about 2MB or more buffer for the
>image capturing. For the performance consideration, we need 2MB buffer
>physical continuous, so we can make use of DMA and other optimization
>way. If we use the dynamic allocation way, sometimes the kernel cannot
>find a 2MB physical-continuous memory slot. Now we just reserve the
>memory when booting up. But it is not very optimal. The memory may not
>be used for a long time. :(
>
>Is there any other way in Linux to allocate big physical-continuous
>memory? I think it may be a typical problem for embedded device. Any
>suggestion or comment will be appreciated!
>

The only thing that comes to mind is trying to do some page migration,
and or memory affinity biasing like what happens in NUMA.  It still
won't provide a guarantee allocation, it would just help with the
probability of being able to allocate the memory.

--mgross