How to use 1.5 GB RAM with 2.2.18 Kernel

["Satyabrata Pradhan" <spradhan@nortelnetworks.com>]

Title: How to use 1.5 GB RAM with 2.2.18 Kernel

Hi linux gurus,

I am currently running 2.2.18 kernel with redhat 6.2 on DELL 1550 machine with 1 GB RAM.
I am allocating several large chunks of memory using vmalloc from one of my kernel module.
The total memory I am allocating is around 860 MB with a maximum of 220 MB for a single vmalloc.

I want to increase this total memory allocation to more than 1 GB and increased my RAM to 1.5 GB.
I am not able to do this and vmalloc fails when I try to use it after what I can get with 1GB RAM.
get_vm_area() (called from vmalloc()) fails at
                if (addr > VMALLOC_END-size) {
                        kfree(area);
                        return NULL;
                }

I will appreciate any help on why this is happening and how to resolve the problem?

Thanks,

Satya.

PS: I am not a kernel expert and know very little about the memory management.