NUMA memory block size

Mike Kravetz kravetz at
Tue Apr 6 03:36:11 EST 2004

On Sat, Apr 03, 2004 at 12:50:13AM -0600, Olof Johansson wrote:
> 2. A lmb_alloc() approach has the benefit of only allocating as much table
> as we actually have physical memory in the system.

Yes and no (if I understand correctly).  The lmb array is currently
limited to 128 entries.  In practice, most of the lmbs are physically
contiguous so they are coalesced into a much smaller number.  However,
couldn't there be a worst case scenario where we could only support
128 16MB lmbs?  Does anyone see a need to be concerned about this?
-OR- Is this just too unlikely to occur?  Does the hypervisor try to
take this type of fragmentation into account?


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