mm, hugetlb: protect reserved pages when soft offlining a hugepage

Don't use the reserve pool when soft offlining a hugepage.  Check we have
free pages outside the reserve pool before we dequeue the huge page.
Otherwise, we can steal other's reserve page.

Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Reviewed-by: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Reviewed-by: Davidlohr Bueso <davidlohr@hp.com>
Cc: David Gibson <david@gibson.dropbear.id.au>
Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com>
Cc: Hillf Danton <dhillf@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Joonsoo Kim 2013-09-11 14:21:51 -07:00 committed by Linus Torvalds
parent 0f1cfe9d0d
commit 4ef9184804

View File

@ -955,9 +955,10 @@ static struct page *alloc_buddy_huge_page(struct hstate *h, int nid)
*/
struct page *alloc_huge_page_node(struct hstate *h, int nid)
{
struct page *page;
struct page *page = NULL;
spin_lock(&hugetlb_lock);
if (h->free_huge_pages - h->resv_huge_pages > 0)
page = dequeue_huge_page_node(h, nid);
spin_unlock(&hugetlb_lock);