With the introduction of kernelcore=, a configurable zone is created on
request. In some cases, this value will be small enough that some nodes
contain only ZONE_MOVABLE. On some NUMA configurations when this occurs,
arch-independent zone-sizing will get the size of the memory holes within
the node incorrect. The value of present_pages goes negative and the boot
fails.
This patch fixes the bug in the calculation of the size of the hole. The
test case is to boot test a NUMA machine with a low value of kernelcore=
before and after the patch is applied. While this bug exists in early
kernel it cannot be triggered in practice.
This patch has been boot-tested on a variety machines with and without
kernelcore= set.
Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
b5445f956e