Re: [PATCH v2 05/12] mm: thp: add core routines for thp/pmd migration

[Naoya Horiguchi]

On Tue, Nov 08, 2016 at 11:05:52AM +0800, kbuild test robot wrote:
> Hi Naoya,
> 
> [auto build test ERROR on mmotm/master]
> [also build test ERROR on v4.9-rc4 next-20161028]
> [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/Naoya-Horiguchi/mm-x86-move-_PAGE_SWP_SOFT_DIRTY-from-bit-7-to-bit-6/20161108-080615
> base:   git://git.cmpxchg.org/linux-mmotm.git master
> config: arm-at91_dt_defconfig (attached as .config)
> compiler: arm-linux-gnueabi-gcc (Debian 6.1.1-9) 6.1.1 20160705
> reproduce:
>         wget https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross -O ~/bin/make.cross
>         chmod +x ~/bin/make.cross
>         # save the attached .config to linux build tree
>         make.cross ARCH=arm 
> 
> All errors (new ones prefixed by >>):
> 
>    In file included from fs/proc/task_mmu.c:14:0:
>    include/linux/swapops.h: In function 'swp_entry_to_pmd':
> >> include/linux/swapops.h:216:14: error: empty scalar initializer
>      pmd_t pmd = {};
>                  ^
>    include/linux/swapops.h:216:14: note: (near initialization for 'pmd')
> 
> vim +216 include/linux/swapops.h
> 
>    210	{
>    211		return swp_entry(0, 0);
>    212	}
>    213	
>    214	static inline pmd_t swp_entry_to_pmd(swp_entry_t entry)
>    215	{
>  > 216		pmd_t pmd = {};
>    217	
>    218		return pmd;
>    219	}

Here is an alternative:

diff --git a/include/linux/swapops.h b/include/linux/swapops.h
index db8a858cc6ff..748c9233b3a5 100644
--- a/include/linux/swapops.h
+++ b/include/linux/swapops.h
@@ -215,9 +215,7 @@ static inline swp_entry_t pmd_to_swp_entry(pmd_t pmd)
 
 static inline pmd_t swp_entry_to_pmd(swp_entry_t entry)
 {
-	pmd_t pmd = {};
-
-	return pmd;
+	return (pmd_t) { 0 };
 }
 
 static inline int is_pmd_migration_entry(pmd_t pmd)

Thanks,
Naoya Horiguchi

> 
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
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