Re: [akpm-mm:mm-unstable 167/506] include/linux/hugetlb.h:1193:9: error: implicit declaration of function 'page_count' is invalid in C99

[Mike Kravetz <mike.kravetz@oracle.com>]

On 01/29/23 13:11, Andrew Morton wrote:
> On Sat, 28 Jan 2023 20:55:08 +0800 kernel test robot <lkp@intel.com> wrote:
> 
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-unstable
> > head:   ede43f2956cc25e387a5e225324104f22e715908
> > commit: 6c096b0425160233d2a8c3ec3f3d82dae5c37678 [167/506] mm: hugetlb: proc: check for hugetlb shared PMD in /proc/PID/smaps
> > config: i386-randconfig-a015 (https://download.01.org/0day-ci/archive/20230128/202301282035.M6wJfQhs-lkp@intel.com/config)
> > compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
> > reproduce (this is a W=1 build):
> >         wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
> >         chmod +x ~/bin/make.cross
> >         # https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git/commit/?id=6c096b0425160233d2a8c3ec3f3d82dae5c37678
> >         git remote add akpm-mm https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git
> >         git fetch --no-tags akpm-mm mm-unstable
> >         git checkout 6c096b0425160233d2a8c3ec3f3d82dae5c37678
> >         # save the config file
> >         mkdir build_dir && cp config build_dir/.config
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 olddefconfig
> >         COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash drivers/infiniband/core/ drivers/net/ethernet/mellanox/mlx5/core/ fs/cifs/
> > 
> > If you fix the issue, kindly add following tag where applicable
> > | Reported-by: kernel test robot <lkp@intel.com>
> > 
> > Note: the akpm-mm/mm-unstable HEAD ede43f2956cc25e387a5e225324104f22e715908 builds fine.
> >       It only hurts bisectability.
> > 
> > All errors (new ones prefixed by >>):
> > 
> >    In file included from drivers/infiniband/core/umem_odp.c:41:
> > >> include/linux/hugetlb.h:1193:9: error: implicit declaration of function 'page_count' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
> >            return page_count(virt_to_page(pte)) > 1;
> >                   ^
> 
> Thanks.
> 
> I hesitate to include mm.h into hugetlb.h, but page_ref.h looks OK.
> 

I was a bit confused because linux/hugetlb.h already includes linux/mm.h
which includes linux/page_ref.h.  Have not yet looked into this more closely.
-- 
Mike Kravetz

> --- a/include/linux/hugetlb.h~mm-hugetlb-proc-check-for-hugetlb-shared-pmd-in-proc-pid-smaps-fix-2
> +++ a/include/linux/hugetlb.h
> @@ -7,6 +7,7 @@
>  #include <linux/fs.h>
>  #include <linux/hugetlb_inline.h>
>  #include <linux/cgroup.h>
> +#include <linux/page_ref.h>
>  #include <linux/list.h>
>  #include <linux/kref.h>
>  #include <linux/pgtable.h>
> _
>