From 4ef91848043679b272a1a5b8e2879acf696ba9e2 Mon Sep 17 00:00:00 2001 From: Joonsoo Kim Date: Wed, 11 Sep 2013 14:21:51 -0700 Subject: [PATCH] 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 Reviewed-by: Aneesh Kumar Cc: Naoya Horiguchi Reviewed-by: Davidlohr Bueso Cc: David Gibson Cc: Wanpeng Li Cc: Hillf Danton Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/hugetlb.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 5b084c7..583db19 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -955,10 +955,11 @@ 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); - page = dequeue_huge_page_node(h, nid); + if (h->free_huge_pages - h->resv_huge_pages > 0) + page = dequeue_huge_page_node(h, nid); spin_unlock(&hugetlb_lock); if (!page) -- 2.7.4