Commit 4ef91848 authored Sep 11, 2013 by Joonsoo Kim Committed by Linus Torvalds Sep 11, 2013

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>

parent 0f1cfe9d

mm/hugetlb.c

+3 −2

Original line number	Original line	Diff line number	Diff line
	@@ -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 alloc_huge_page_node(struct hstate h, int nid)
	{		{
	struct page *page;		struct page *page = NULL;

	spin_lock(&hugetlb_lock);		spin_lock(&hugetlb_lock);
			if (h->free_huge_pages - h->resv_huge_pages > 0)
	page = dequeue_huge_page_node(h, nid);		page = dequeue_huge_page_node(h, nid);
	spin_unlock(&hugetlb_lock);		spin_unlock(&hugetlb_lock);