ioremap() fails for >64 MB

Alex Zeffertt ajz at
Tue Aug 22 18:50:53 EST 2006

Phil Nitschke wrote:
> Hi all,
> I have 2 GB memory on a 7448 processor, and want to reserve a huge chunk
> of it at boot-time, then ioremap() it into the kernel space inside a
> device driver.  So far I've succeeded with 64 MB, but can't go any
> higher, as mm/vmalloc.c tells me: "allocation failed: out of vmalloc
> space - use vmalloc=<size> to increase size."

I remember reading in Linux Device Drivers that you can use the bigphysarea
patch to allocate large memory, as long as you do it at boot time.  It seems
it's been ported to 2.6 too:


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