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.

n-horiguchi@ah.jp.nec.com 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/1470624546-902-1-git-send-email-zhongjiang@huawei.com
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
zhong jiang 2016-08-11 15:32:55 -07:00 committed by Linus Torvalds
parent 85e97be32c
commit c1470b33bb

View File

@ -1448,6 +1448,7 @@ static void dissolve_free_huge_page(struct page *page)
list_del(&page->lru);
h->free_huge_pages--;
h->free_huge_pages_node[nid]--;
h->max_huge_pages--;
update_and_free_page(h, page);
}
spin_unlock(&hugetlb_lock);