From: Hugh Dickins <hughd@xxxxxxxxxx> Subject: mm/shmem: fix build without THP Some optimizers don't notice that shmem_punch_compound() is always true (PageTransCompound() being false) without CONFIG_TRANSPARENT_HUGEPAGE==y: use IS_ENABLED to help them to avoid the BUILD_BUG inside HPAGE_PMD_NR. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2004142339170.10035@eggly.anvils Fixes: 71725ed10c40 ("mm: huge tmpfs: try to split_huge_page() when punching hole") Signed-off-by: Hugh Dickins <hughd@xxxxxxxxxx> Reported-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Tested-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/shmem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/shmem.c~mm-shmem-fix-build-without-thp +++ a/mm/shmem.c @@ -952,7 +952,7 @@ static void shmem_undo_range(struct inod VM_BUG_ON_PAGE(PageWriteback(page), page); if (shmem_punch_compound(page, start, end)) truncate_inode_page(mapping, page); - else { + else if (IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) { /* Wipe the page and don't get stuck */ clear_highpage(page); flush_dcache_page(page); _
