fs/proc/task_mmu.c: add workaround for old compilers
For THP=n, HPAGE_PMD_NR in smaps_account() expands to BUILD_BUG().
That's fine since this codepath is eliminated by modern compilers.
But older compilers have not that efficient dead code elimination. It
causes problem at least with gcc 4.1.2 on m68k:
fs/built-in.o: In function `smaps_account':
task_mmu.c:(.text+0x4f8fa): undefined reference to `__compiletime_assert_471'
Let's replace HPAGE_PMD_NR with 1 << compound_order(page).
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 65a1b6c..71ffc91 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -468,7 +468,7 @@
static void smaps_account(struct mem_size_stats *mss, struct page *page,
bool compound, bool young, bool dirty)
{
- int i, nr = compound ? HPAGE_PMD_NR : 1;
+ int i, nr = compound ? 1 << compound_order(page) : 1;
unsigned long size = nr * PAGE_SIZE;
if (PageAnon(page))