On 25 May 2017, at 18:43, Andrew Morton wrote:

> On Thu, 25 May 2017 13:19:54 -0400 "Zi Yan" <zi.yan@cs.rutgers.edu> wrote:
>
>> On 25 May 2017, at 13:06, kbuild test robot wrote:
>>
>>> Hi Zi,
>>>
>>> [auto build test WARNING on mmotm/master]
>>> [also build test WARNING on v4.12-rc2 next-20170525]
>>> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
>>>
>>> url:    https://github.com/0day-ci/linux/commits/Zi-Yan/mm-page-migration-enhancement-for-thp/20170526-003749
>>> base:   git://git.cmpxchg.org/linux-mmotm.git master
>>> config: i386-randconfig-x016-201721 (attached as .config)
>>> compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
>>> reproduce:
>>>         # save the attached .config to linux build tree
>>>         make ARCH=i386
>>>
>>> All warnings (new ones prefixed by >>):
>>>
>>>    In file included from fs/proc/task_mmu.c:15:0:
>>>    include/linux/swapops.h: In function 'swp_entry_to_pmd':
>>>>> include/linux/swapops.h:222:16: warning: missing braces around initializer [-Wmissing-braces]
>>>      return (pmd_t){{ 0 }};
>>>                    ^
>>
>> The braces are added to eliminate the warning from "m68k-linux-gcc (GCC) 4.9.0",
>> which has the bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119.
>
> I think we'd prefer to have a warning on m68k than on i386!  Is there
> something smarter we can do here?

I will remove the braces in the next version.

The bug is present in gcc 4.8 and 4.9 and m68k has newer gcc to use,
so kbuild test robot needs to upgrade its m68k gcc (maybe it has done it).

—
Best Regards,
Yan Zi