Re: [mmotm:master 50/189] include/linux/swapops.h:220:9: error: implicit declaration of function '__pmd'

["Zi Yan" <zi.yan@cs.rutgers.edu>]

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On 1 Aug 2017, at 17:38, Andrew Morton wrote:

> On Tue, 1 Aug 2017 19:57:54 +0800 kbuild test robot <fengguang.wu@intel.com> wrote:
>
>> tree:   git://git.cmpxchg.org/linux-mmotm.git master
>> head:   7961d18ba492e06ad240d37a5502c418b5f0a928
>> commit: 25faf0ef110322719330fcadf4fe541528bacd4d [50/189] mm-thp-enable-thp-migration-in-generic-path-fix
>> config: sparc-defconfig (attached as .config)
>> compiler: sparc-linux-gcc (GCC) 6.2.0
>> reproduce:
>>         wget https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fraw.githubusercontent.com%2F01org%2Flkp-tests%2Fmaster%2Fsbin%2Fmake.cross&data=02%7C01%7Czi.yan%40cs.rutgers.edu%7C30301965f5964988c18f08d4d925b5f4%7Cb92d2b234d35447093ff69aca6632ffe%7C1%7C0%7C636372203371243236&sdata=QEB2C6y9u7ZfV4Ej%2F8M0BLMUi%2FI2XFVHStMPvPeyiFA%3D&reserved=0 -O ~/bin/make.cross
>>         chmod +x ~/bin/make.cross
>>         git checkout 25faf0ef110322719330fcadf4fe541528bacd4d
>>         # save the attached .config to linux build tree
>>         make.cross ARCH=sparc
>>
>> All errors (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:220:9: error: implicit declaration of function '__pmd' [-Werror=implicit-function-declaration]
>>      return __pmd(0);
>>             ^~~~~
>>>> include/linux/swapops.h:220:9: error: incompatible types when returning type 'int' but 'pmd_t {aka struct <anonymous>}' was expected
>>      return __pmd(0);
>>             ^~~~~~~~
>>    cc1: some warnings being treated as errors
>>
>> vim +/__pmd +220 include/linux/swapops.h
>>
>>    217	
>>    218	static inline pmd_t swp_entry_to_pmd(swp_entry_t entry)
>>    219	{
>>> 220		return __pmd(0);
>>    221	}
>>    222	
>>
>
> Seems that sparc32 forgot to implement __pmd()?

Hi Sam,

I saw __pmd() was deleted at commit 6e6e41879: sparc32: fix build with STRICT_MM_TYPECHECKS.
It was commented out at least since 2008, before commit a439fe51a.

Is there any way to bring it back? Since __pmd() can help us work around a GCC zero initializer bug.

Thanks.

—
Best Regards,
Yan Zi

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