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.

--
Best Regards
Yan Zi