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

[Christophe Leroy]

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@xxxxxxxxx>
>
> 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/

[...]


> > > 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