From: Adam Litke On Tue, 2008-03-04 at 11:51 -0800, Andrew Morton wrote: > hugetlb-correct-page-count-for-surplus-huge-pages.patch adds: > > if (page) { > /* > * This page is now managed by the hugetlb allocator and has > * no users -- drop the buddy allocator's reference. > */ > int page_count = put_page_testzero(page); > BUG_ON(page_count != 0); > > Ugh I got bitten by put_page_testzero(). When it returns 1, the page count is zero (not the page count). My initial version had a BUG_ON() with side-effects. When a reviewer pointed it out, I thought I could fix the patch up on its way out the door. I have self-administered my punishment. This patch will fix it: Signed-off-by: Adam Litke Cc: Kamalesh Babulal Signed-off-by: Andrew Morton --- mm/hugetlb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN mm/hugetlb.c~hugetlb-correct-page-count-for-surplus-huge-pages-fix mm/hugetlb.c --- a/mm/hugetlb.c~hugetlb-correct-page-count-for-surplus-huge-pages-fix +++ a/mm/hugetlb.c @@ -290,8 +290,8 @@ static struct page *alloc_buddy_huge_pag * This page is now managed by the hugetlb allocator and has * no users -- drop the buddy allocator's reference. */ - int page_count = put_page_testzero(page); - BUG_ON(page_count != 0); + put_page_testzero(page); + VM_BUG_ON(page_count(page)); nid = page_to_nid(page); set_compound_page_dtor(page, free_huge_page); /* _