10MB buffer

10MB buffer

[Bloch, Jack]

I am running a SuSE 2.4.19 Kernel and have a requirement to allocate a 10MB
buffer (page aligned).

Is this possbile via alloc_bootmem_pages?

If so, how does my driver get access to this memory. I assume I have to
modify main.c to actually allocate the memory. My driver will get loaded
much later and this 10MB needs to be available all the time. Please CC me on
any responses.


Thanks in advance...

Jack Bloch 
Siemens ICN
phone                (561) 923-6550
e-mail                jack.bloch@icn.siemens.com

Re: 10MB buffer

[Carl Spalletta]

> I am running a SuSE 2.4.19 Kernel and have a requirement
> to allocate a 10MB buffer (page aligned).

I suppose you mean contiguous in physical memory?
And accessible from userspace?

> Is this possbile via alloc_bootmem_pages?

This may be impossbile [sic].
see www.csn.ul.ie/~mel/projects/vm/guide/html/understand/node37.html

also see LKML thread "Re: mapping physical memory":

"tell the kernel that you have 8MB *less* RAM than is actually present
using a "mem=" directive at boot, then grab that last piece of memory
by mmap'ing /dev/mem."

see utah-glx.sourceforge.net/memory-usage.html


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