Is there any way to increase the KVM?

John Baldwin jhb at
Fri Jun 6 20:57:03 UTC 2008

On Friday 06 June 2008 08:18:36 am Dag-Erling Smørgrav wrote:
> Jeremy Chadwick <koitsu at> writes:
> > That's great to hear, but the point I've made regarding kmem_size not
> > being able to extend past 2GB (on i386 and amd64) still stands.  I've
> > looked at the code myself, in attempt to figure out where the actual
> > limitation is, and the code is beyond my understanding.
> IIRC, it's a hardware limitation.  Search the archives for "kmem_size"
> and my name for a full explanation.

While global variables have to be within 2GB for %rip relative addressing, 
there's no reason malloc'd buffers can't be anywhere in the 64-bit address 
space since pointers are 64-bits.

John Baldwin

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