mm/hugetlb: fix incorrect hugepages count during mem hotplug

When memory hotplug operates, free hugepages will be freed if the
movable node is offline.  Therefore, /proc/sys/vm/nr_hugepages will be
incorrect.

Fix it by reducing max_huge_pages when the node is offlined.

[email protected] said:

: dissolve_free_huge_page intends to break a hugepage into buddy, and the
: destination hugepage is supposed to be allocated from the pool of the
: destination node, so the system-wide pool size is reduced.  So adding
: h->max_huge_pages-- makes sense to me.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: zhong jiang <[email protected]>
Cc: Mike Kravetz <[email protected]>
Acked-by: Naoya Horiguchi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
1 file changed