path: root/mm
diff options
authorMike Kravetz <mike.kravetz@oracle.com>2016-02-05 15:36:38 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2016-02-05 18:10:40 -0800
commitb4330afbed0cdceeba33c4945158c55771047e81 (patch)
tree422b578bbf19e4d4c4dea5d742cc4e6dfd000a30 /mm
parentcf2a82ee432730ab25c21d054c67f296af4fc4bd (diff)
mm/hugetlb: fix gigantic page initialization/allocation
Attempting to preallocate 1G gigantic huge pages at boot time with "hugepagesz=1G hugepages=1" on the kernel command line will prevent booting with the following: kernel BUG at mm/hugetlb.c:1218! When mapcount accounting was reworked, the setting of compound_mapcount_ptr in prep_compound_gigantic_page was overlooked. As a result, the validation of mapcount in free_huge_page fails. The "BUG_ON" checks in free_huge_page were also changed to "VM_BUG_ON_PAGE" to assist with debugging. Fixes: 53f9263baba69 ("mm: rework mapcount accounting to enable 4k mapping of THPs") Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: David Rientjes <rientjes@google.com> Tested-by: Vlastimil Babka <vbabka@suse.cz> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
1 files changed, 3 insertions, 2 deletions
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 12908dcf5831..d7a802427ea8 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -1214,8 +1214,8 @@ void free_huge_page(struct page *page)
set_page_private(page, 0);
page->mapping = NULL;
- BUG_ON(page_count(page));
- BUG_ON(page_mapcount(page));
+ VM_BUG_ON_PAGE(page_count(page), page);
+ VM_BUG_ON_PAGE(page_mapcount(page), page);
restore_reserve = PagePrivate(page);
@@ -1286,6 +1286,7 @@ static void prep_compound_gigantic_page(struct page *page, unsigned int order)
set_page_count(p, 0);
set_compound_head(p, page);
+ atomic_set(compound_mapcount_ptr(page), -1);