[PATCH RFC v2 2/5] mm: add __always_inline for page_contains_unaccepted

[Chen Linxuan <chenlinxuan@uniontech.com>]

From: Winston Wen <wentao@uniontech.com>

On x86_64 with gcc version 13.3.0, I compile mm/page_alloc.c with:

  make defconfig
  make KCFLAGS="-fno-inline-small-functions -fno-inline-functions-called-once" \
    mm/page_alloc.o

Then I get a compile error:

    CALL    scripts/checksyscalls.sh
    DESCEND objtool
    INSTALL libsubcmd_headers
    CC      mm/page_alloc.o
  In file included from <command-line>:
  mm/page_alloc.c: In function '__free_unaccepted.isra':
  ././include/linux/compiler_types.h:557:45: error: call to '__compiletime_assert_1013' declared with attribute error: BUILD_BUG failed
    557 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
        |                                             ^
  ././include/linux/compiler_types.h:538:25: note: in definition of macro '__compiletime_assert'
    538 |                         prefix ## suffix();                             \
        |                         ^~~~~~
  ././include/linux/compiler_types.h:557:9: note: in expansion of macro '_compiletime_assert'
    557 |         _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
        |         ^~~~~~~~~~~~~~~~~~~
  ./include/linux/build_bug.h:39:37: note: in expansion of macro 'compiletime_assert'
     39 | #define BUILD_BUG_ON_MSG(cond, msg) compiletime_assert(!(cond), msg)
        |                                     ^~~~~~~~~~~~~~~~~~
  ./include/linux/build_bug.h:59:21: note: in expansion of macro 'BUILD_BUG_ON_MSG'
     59 | #define BUILD_BUG() BUILD_BUG_ON_MSG(1, "BUILD_BUG failed")
        |                     ^~~~~~~~~~~~~~~~
  mm/page_alloc.c:7301:9: note: in expansion of macro 'BUILD_BUG'
   7301 |         BUILD_BUG();
        |         ^~~~~~~~~

Marking page_contains_unaccepted with __always_inline and let dead code
elimination remove reference to __free_unaccepted() here.

Co-developed-by: Chen Linxuan <chenlinxuan@uniontech.com>
Signed-off-by: Chen Linxuan <chenlinxuan@uniontech.com>
Signed-off-by: Winston Wen <wentao@uniontech.com>
---
 mm/page_alloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index fd6b865cb1abfbd3d2ebd67cdaa5f86d92a62e14..7c0934c818ddc719c2dcb813599708f47d56352c 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7286,7 +7286,7 @@ static bool __free_unaccepted(struct page *page)
 
 #else
 
-static bool page_contains_unaccepted(struct page *page, unsigned int order)
+static __always_inline bool page_contains_unaccepted(struct page *page, unsigned int order)
 {
 	return false;
 }

-- 
2.48.1