Re: [linux-next:master 9078/9582] arch/arm64/include/asm/pgtable.h:238:0: warning: "HUGE_MAX_HSTATE" redefined

[Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>]

On Thu, Aug 20, 2015 at 01:01:48AM +0000, Horiguchi Naoya(堀口 直也) wrote:
> On Wed, Aug 19, 2015 at 02:33:05PM -0700, Andrew Morton wrote:
> > On Wed, 19 Aug 2015 21:32:40 +0800 kbuild test robot <fengguang.wu@intel.com> wrote:
> > 
> > > tree:   git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> > > head:   dcaa9a3e88c4082096bfed62d9de2d9b6ad9e3d6
> > > commit: 878b6f5bcef8de64a5c39b685e785166357bf0dc [9078/9582] mm-hugetlb-proc-add-hugetlbpages-field-to-proc-pid-status-fix-3
> > > config: arm64-allmodconfig (attached as .config)
> > > 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
> > >   git checkout 878b6f5bcef8de64a5c39b685e785166357bf0dc
> > >   # save the attached .config to linux build tree
> > >   make.cross ARCH=arm64 
> > > 
> > > All warnings (new ones prefixed by >>):
> > > 
> > >    In file included from include/linux/mm.h:54:0,
> > >                     from arch/arm64/kernel/asm-offsets.c:22:
> > > >> arch/arm64/include/asm/pgtable.h:238:0: warning: "HUGE_MAX_HSTATE" redefined
> > >     #define HUGE_MAX_HSTATE  2
> > >     ^
> > >    In file included from include/linux/sched.h:27:0,
> > >                     from arch/arm64/kernel/asm-offsets.c:21:
> > >    include/linux/mm_types.h:372:0: note: this is the location of the previous definition
> > >     #define HUGE_MAX_HSTATE 1
> > 
> > I've spent far too long trying to come up with a nice fix for this and
> > everything I try leads down a path of horror.  Our include files are a
> > big mess.
> 
> Thanks for digging this. I agree to the direction of splitting header files
> to reduce the complexity of header dependency. But if we need a quick fix
> until your work in another email is merged, the following should work.
> 
> # I'll take a look on your patch.
> 
> Thanks,
> Naoya Horiguchi
> ---
> From: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
> Subject: [PATCH] hugetlb: overwrite HUGE_MAX_HSTATE definition
> 
> This dirty workaround will be removed when the circular dependency of
> header files around mm_types.h and sched.h is fixed.
> 
> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>

sorry, this doesn't work because when we include mm_types.h first,
struct hugetlb_usage has only one counter even if HUGE_MAX_HSTATE is
overwritten afterward.
It might be good to add just a pointer struct hugetlb_usage* in mm_struct,
which doesn't require HUGE_MAX_HSTATE in inclusion of mm_types.h.

Thanks,
Naoya Horiguchi

> ---
>  arch/arm64/include/asm/pgtable.h  | 3 +++
>  arch/powerpc/include/asm/page.h   | 3 +++
>  arch/tile/include/asm/page.h      | 3 +++
>  arch/x86/include/asm/page_types.h | 3 +++
>  4 files changed, 12 insertions(+)
> 
> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
> index 56283f8a675c..01208204dbb3 100644
> --- a/arch/arm64/include/asm/pgtable.h
> +++ b/arch/arm64/include/asm/pgtable.h
> @@ -235,6 +235,9 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
>  /*
>   * Hugetlb definitions.
>   */
> +#if defined(HUGE_MAX_HSTATE) && HUGE_MAX_HSTATE == 1
> +#undef HUGE_MAX_HSTATE
> +#endif
>  #define HUGE_MAX_HSTATE		2
>  #define HPAGE_SHIFT		PMD_SHIFT
>  #define HPAGE_SIZE		(_AC(1, UL) << HPAGE_SHIFT)
> diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h
> index 71294a6e976e..19ee05520353 100644
> --- a/arch/powerpc/include/asm/page.h
> +++ b/arch/powerpc/include/asm/page.h
> @@ -45,6 +45,9 @@ extern unsigned int HPAGE_SHIFT;
>  #define HPAGE_SIZE		((1UL) << HPAGE_SHIFT)
>  #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
>  #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
> +#if defined(HUGE_MAX_HSTATE) && HUGE_MAX_HSTATE == 1
> +#undef HUGE_MAX_HSTATE
> +#endif
>  #define HUGE_MAX_HSTATE		(MMU_PAGE_COUNT-1)
>  #endif
>  
> diff --git a/arch/tile/include/asm/page.h b/arch/tile/include/asm/page.h
> index a213a8d84a95..dac32bd65b99 100644
> --- a/arch/tile/include/asm/page.h
> +++ b/arch/tile/include/asm/page.h
> @@ -136,6 +136,9 @@ static inline __attribute_const__ int get_order(unsigned long size)
>  
>  #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
>  
> +#if defined(HUGE_MAX_HSTATE) && HUGE_MAX_HSTATE == 1
> +#undef HUGE_MAX_HSTATE
> +#endif
>  #define HUGE_MAX_HSTATE		6
>  
>  #ifdef CONFIG_HUGETLB_PAGE
> diff --git a/arch/x86/include/asm/page_types.h b/arch/x86/include/asm/page_types.h
> index c7c712f2648b..747fa3b5ea3f 100644
> --- a/arch/x86/include/asm/page_types.h
> +++ b/arch/x86/include/asm/page_types.h
> @@ -25,6 +25,9 @@
>  #define HPAGE_MASK		(~(HPAGE_SIZE - 1))
>  #define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
>  
> +#if defined(HUGE_MAX_HSTATE) && HUGE_MAX_HSTATE == 1
> +#undef HUGE_MAX_HSTATE
> +#endif
>  #define HUGE_MAX_HSTATE 2
>  
>  #define PAGE_OFFSET		((unsigned long)__PAGE_OFFSET)
> -- 
> 2.4.3