[RFC PATCH 17/24] mm/hugetlb: Add a BUILD_BUG_ON to check if struct page size is a power of two
From: Muchun Song <hidden>
Date: 2020-09-16 00:42:27
Also in:
linux-fsdevel, linux-mm, lkml
Subsystem:
hugetlb subsystem, memory management, the rest · Maintainers:
Muchun Song, Oscar Salvador, Andrew Morton, Linus Torvalds
We only can free the unused vmemmap to the buddy system when the size of struct page is a power of two. So add a BUILD_BUG_ON to check the illegal case. Signed-off-by: Muchun Song <redacted> --- mm/hugetlb.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 7072b849af3d..34706cec21ec 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c@@ -3817,6 +3817,10 @@ static int __init hugetlb_init(void) { int i; +#ifdef CONFIG_HUGETLB_PAGE_FREE_VMEMMAP + BUILD_BUG_ON_NOT_POWER_OF_2(sizeof(struct page)); +#endif + if (!hugepages_supported()) { if (hugetlb_max_hstate || default_hstate_max_huge_pages) pr_warn("HugeTLB: huge pages not supported, ignoring associated command-line parameters\n");
--
2.20.1