Re: [PATCH v1 39/46] powerpc/8xx: Add a function to early map kernel via huge pages

From: Christophe Leroy <christophe.leroy@c-s.fr>
To: Paul Mackerras <paulus@samba.org>, Michael Ellerman <mpe@ellerman.id.au>
Cc: kbuild test robot <lkp@intel.com>,
	kbuild-all@lists.01.org, linux-kernel@vger.kernel.org,
	linuxppc-dev@lists.ozlabs.org
Subject: Re: [PATCH v1 39/46] powerpc/8xx: Add a function to early map kernel via huge pages
Date: Thu, 2 Apr 2020 12:13:22 +0200	[thread overview]
Message-ID: <2e56a9e4-6176-7a19-81b3-c36d6243e776@c-s.fr> (raw)
In-Reply-To: <22bc0bba-533f-548b-8eec-a3392acc8e3d@c-s.fr>


Le 17/03/2020 à 15:43, Christophe Leroy a écrit :
> 
> 
> Le 17/03/2020 à 02:39, kbuild test robot a écrit :
>> Hi Christophe,
>>
>> Thank you for the patch! Yet something to improve:
>>
>> [auto build test ERROR on next-20200316]
>> [cannot apply to powerpc/next v5.6-rc6 v5.6-rc5 v5.6-rc4 v5.6-rc6]
>> [if your patch is applied to the wrong git tree, please drop us a note 
>> to help
>> improve the system. BTW, we also suggest to use '--base' option to 
>> specify the
>> base tree in git format-patch, please see 
>> https://stackoverflow.com/a/37406982]
>>
>> url:    
>> https://github.com/0day-ci/linux/commits/Christophe-Leroy/Use-hugepages-to-map-kernel-mem-on-8xx/20200317-065610 
>>
>> base:    8548fd2f20ed19b0e8c0585b71fdfde1ae00ae3c
>> config: powerpc-tqm8xx_defconfig (attached as .config)
>> compiler: powerpc-linux-gcc (GCC) 9.2.0
>> reproduce:
>>          wget 
>> https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross 
>> -O ~/bin/make.cross
>>          chmod +x ~/bin/make.cross
>>          # save the attached .config to linux build tree
>>          GCC_VERSION=9.2.0 make.cross ARCH=powerpc
>>
>> If you fix the issue, kindly add following tag
>> Reported-by: kbuild test robot <lkp@intel.com>
>>
>> All errors (new ones prefixed by >>):
>>
>>     In file included from arch/powerpc/mm/fault.c:33:
>>     include/linux/hugetlb.h: In function 'hstate_inode':
>>>> include/linux/hugetlb.h:522:9: error: implicit declaration of 
>>>> function 'HUGETLBFS_SB'; did you mean 'HUGETLBFS_MAGIC'? 
>>>> [-Werror=implicit-function-declaration]
>>       522 |  return HUGETLBFS_SB(i->i_sb)->hstate;
>>           |         ^~~~~~~~~~~~
>>           |         HUGETLBFS_MAGIC
>>>> include/linux/hugetlb.h:522:30: error: invalid type argument of '->' 
>>>> (have 'int')
>>       522 |  return HUGETLBFS_SB(i->i_sb)->hstate;
>>           |                              ^~
>>     cc1: all warnings being treated as errors
> 
> hstate_inode() shouldn't use HUGETLBFS_SB() which CONFIG_HUGETLBFS is 
> not set.
> 
> Proposed fix at https://patchwork.ozlabs.org/patch/1256108/

The fix is going in 5.7 via mm tree it seems, see 
https://patchwork.kernel.org/patch/11470105/

Christophe

> 
> [...]
> 
> 
>>>> include/linux/hugetlb.h:522:30: error: invalid type argument of '->' 
>>>> (have 'int')
>>       522 |  return HUGETLBFS_SB(i->i_sb)->hstate;
>>           |                              ^~
>>     At top level:
>>     arch/powerpc//mm/nohash/8xx.c:73:18: error: 
>> '__early_map_kernel_hugepage' defined but not used 
>> [-Werror=unused-function]
>>        73 | static int __ref __early_map_kernel_hugepage(unsigned long 
>> va, phys_addr_t pa,
>>           |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~
>>     cc1: all warnings being treated as errors
> 
> This patch is a preparation patch. The function is not used yet, that's 
> normal. Ok, it breaks bisectability. Should it be squashed with the 
> first user of the function ?
> 
> Christophe