thp: add HPAGE_PMD_* definitions for !CONFIG_TRANSPARENT_HUGEPAGE

These macros will be used in a later patch, where all usages are expected
to be optimized away without #ifdef CONFIG_TRANSPARENT_HUGEPAGE.  But to
detect unexpected usages, we convert the existing BUG() to BUILD_BUG().

[akpm@linux-foundation.org: fix build in mm/pgtable-generic.c]
Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Acked-by: Hillf Danton <dhillf@gmail.com>
Reviewed-by: Andrea Arcangeli <aarcange@redhat.com>
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 2 deletions

diff --git a/mm/pgtable-generic.c b/mm/pgtable-generic.c
index eb663fb533e0..5a74fea182f1 100644
--- a/mm/pgtable-generic.c
+++ b/mm/pgtable-generic.c
@@ -70,10 +70,11 @@ int pmdp_clear_flush_young(struct vm_area_struct *vma,
                            unsigned long address, pmd_t *pmdp)
 {
         int young;
-#ifndef CONFIG_TRANSPARENT_HUGEPAGE
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+        VM_BUG_ON(address & ~HPAGE_PMD_MASK);
+#else
         BUG();
 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-        VM_BUG_ON(address & ~HPAGE_PMD_MASK);
         young = pmdp_test_and_clear_young(vma, address, pmdp);
         if (young)
                 flush_tlb_range(vma, address, address + HPAGE_PMD_SIZE);