bug: completely remove code generated by disabled VM_BUG_ON()

0 Fork 0

mirror of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git synced 2026-11-05 17:13:47 +01:00

Even if CONFIG_DEBUG_VM=n gcc genereates code for some VM_BUG_ON()

for example VM_BUG_ON(!PageCompound(page) || !PageHead(page)); in
do_huge_pmd_wp_page() generates 114 bytes of code.

But they mostly disappears when I split this VM_BUG_ON into two:

  -VM_BUG_ON(!PageCompound(page) || !PageHead(page));
  +VM_BUG_ON(!PageCompound(page));
  +VM_BUG_ON(!PageHead(page));

weird... but anyway after this patch code disappears completely.

  add/remove: 0/0 grow/shrink: 7/97 up/down: 135/-1784 (-1649)

Signed-off-by: Konstantin Khlebnikov <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Geert Uytterhoeven <[email protected]>
Cc: "H. Peter Anvin" <[email protected]>
Cc: Cong Wang <[email protected]>
Cc: Hugh Dickins <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

This commit is contained in:

Konstantin Khlebnikov authored and

Linus Torvalds committed 2012-05-29 16:22:20 -07:00

1 parent baf05aa927

commit 02602a18c3

1 file changed

+1 -1

									
										include/linux/mmdebug.h
									
		+1
		-1
	
												View File
												
				@@ -4,7 +4,7 @@

				#ifdef CONFIG_DEBUG_VM

				#define VM_BUG_ON(cond) BUG_ON(cond)

				#else

				#define VM_BUG_ON(cond) do { (void)(cond); } while (0)

				#define VM_BUG_ON(cond) BUILD_BUG_ON_INVALID(cond)

				#endif

				#ifdef CONFIG_DEBUG_VIRTUAL