Re: allocate more than 2 GB on IA32

[Martin J. Bligh]

> i would like to allocate more than 2 GB of memory on an IA32 architecture.
> 
> The machine is a dual XEON_DP with 3 GB of Ram and 4 GB of swap space.
> 
> I have tried with the default SUSE 8.1 kernel as well as with a
> 2.4.20-pre4aa1 Kernel compile by my own using these Options:
> 
> CONFIG_HIGHMEM4G=y
> CONFIG_HIGHMEM=y
> CONFIG_1GB=y
> 
> but I am only able to allocate 2 GB with a single malloc call.
> I tought it should be possible to allocate up to 2.9 GB of memory to a
> process, with this kernel settings.

Well, assuming you had no user-space code or data, or a stack, or any
shared libraries to fit into that space as well ;-)

Try shifting TASK_UNMAPPED_BASE down from 1GB to 0.5GB - that should give
you some more breathing room, though you'll never get to 2.9GB.

M.