| From | Muchun Song <> | Subject | [RFC PATCH 24/24] mm/hugetlb: Add BUILD_BUG_ON to catch invalid usage of tail struct page | Date | Tue, 15 Sep 2020 20:59:47 +0800 |
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There are only `RESERVE_VMEMMAP_SIZE / sizeof(struct page)` struct pages can be used when CONFIG_HUGETLB_PAGE_FREE_VMEMMAP, so add a BUILD_BUG_ON to catch this invalid usage of tail struct page.
Signed-off-by: Muchun Song <songmuchun@bytedance.com> --- mm/hugetlb.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c index e66c3f10c583..63995ba74b6b 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -3994,6 +3994,8 @@ static int __init hugetlb_init(void) #ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP BUILD_BUG_ON_NOT_POWER_OF_2(sizeof(struct page)); + BUILD_BUG_ON(NR_USED_SUBPAGE >= + RESERVE_VMEMMAP_SIZE / sizeof(struct page)); #endif if (!hugepages_supported()) { -- 2.20.1
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