Using Graphics Card Memory as Swap

[molostoff]

I have one unbranded desktop with two graphic cards (one onboard, and one in agp slot). Currently only one is used with desktop, but another still has 128M its own graphics memory. I have found a wiki link http://en.gentoo-wiki.com/wiki/Using...Memory_as_Swap with a description on how to use these 128M as a swap device.

But I was unsuccessful:

root@home:~# cat /etc/modules
phram phram=swap,0xf0000000,128Mi
mtdblock
loop
# lp

root@home:~# cat /proc/mtd
dev:  size  erasesize name
mtd0: 08000000 00001000 "swap"

root@home:~# ls -la /dev/mtd*
crw-rw---- 1 root root 90, 0 2010-07-06 05:34 /dev/mtd0
crw-rw---- 1 root root 90, 1 2010-07-06 05:34 /dev/mtd0ro
brw-rw---- 1 root disk 31, 0 2010-07-06 05:36 /dev/mtdblock0

root@home:~# mkswap -c /dev/mtdblock0 
Setting up swapspace version 1, size = 131068 KiB
no label, UUID=4cb264a0-a98c-4de4-b958-efcefb75b056

root@home:~# swapon /dev/mtdblock0
swapon: /dev/mtdblock0: read swap header failed: Invalid argument

What it is wrong with swapon? dmesg is empty on this.