Re: include/linux/huge_mm.h:285:undefined reference to `mthp_stats'

[Yujie Liu <yujie.liu@intel.com>]

On Fri, May 24, 2024 at 09:00:45AM +1200, Barry Song wrote:
> > tree:   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
> > head:   c760b3725e52403dc1b28644fb09c47a83cacea6
> > commit: ec33687c674934dfefd782a8ffd58370b080b503 mm: add per-order mTHP anon_fault_alloc and anon_fault_fallback counters
> > date:   2 weeks ago
> > config: s390-randconfig-r005-20230226 (https://download.01.org/0day-ci/archive/20240523/202405231728.tCAogiSI-lkp@intel.com/config)
> > compiler: s390-linux-gcc (GCC) 13.2.0
> > reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240523/202405231728.tCAogiSI-lkp@intel.com/reproduce)
> 
> > If you fix the issue in a separate patch/commit (i.e. not just a new version of
> > the same patch/commit), kindly add following tags
> > | Reported-by: kernel test robot <lkp@intel.com>
> > | Closes: https://lore.kernel.org/oe-kbuild-all/202405231728.tCAogiSI-lkp@intel.com/
> > 
> > All errors (new ones prefixed by >>):
> > 
> >    s390-linux-ld: mm/memory.o: in function `count_mthp_stat':
> >>> include/linux/huge_mm.h:285:(.text+0x191c): undefined reference to `mthp_stats'
> >    s390-linux-ld: mm/huge_memory.o:(.rodata+0x10): undefined reference to `mthp_stats'
> > 
> > 
> > vim +285 include/linux/huge_mm.h
> > 
> >    279	
> >    280	static inline void count_mthp_stat(int order, enum mthp_stat_item item)
> >    281	{
> >    282		if (order <= 0 || order > PMD_ORDER)
> >    283			return;
> >    284	
> >>   285		this_cpu_inc(mthp_stats.stats[order][item]);
> >    286	}
> >    287	
> 
> Thanks, would you please test if the below patch fixes the problem,

The patch below fixes the problem for me. Thanks.

Tested-by: Yujie Liu <yujie.liu@intel.com>

> 
> From: Barry Song <v-songbaohua@oppo.com>
> Date: Fri, 24 May 2024 08:50:48 +1200
> Subject: [PATCH] mm: huge_mm: fix undefined reference to `mthp_stats' for
>  CONFIG_SYSFS=n
> 
> if CONFIG_SYSFS is not enabled in config, we get the below error,
> 
> All errors (new ones prefixed by >>):
> 
>    s390-linux-ld: mm/memory.o: in function `count_mthp_stat':
> >> include/linux/huge_mm.h:285:(.text+0x191c): undefined reference to `mthp_stats'
>    s390-linux-ld: mm/huge_memory.o:(.rodata+0x10): undefined reference to `mthp_stats'
> 
> vim +285 include/linux/huge_mm.h
> 
>    279
>    280  static inline void count_mthp_stat(int order, enum mthp_stat_item item)
>    281  {
>    282          if (order <= 0 || order > PMD_ORDER)
>    283                  return;
>    284
>  > 285          this_cpu_inc(mthp_stats.stats[order][item]);
>    286  }
>    287
> 
> Reported-by: kernel test robot <lkp@intel.com>
> Closes: https://lore.kernel.org/oe-kbuild-all/202405231728.tCAogiSI-lkp@intel.com/
> Signed-off-by: Barry Song <v-songbaohua@oppo.com>
> ---
>  include/linux/huge_mm.h | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
> index c8d3ec116e29..09c5744d9124 100644
> --- a/include/linux/huge_mm.h
> +++ b/include/linux/huge_mm.h
> @@ -278,6 +278,7 @@ struct mthp_stat {
>  	unsigned long stats[ilog2(MAX_PTRS_PER_PTE) + 1][__MTHP_STAT_COUNT];
>  };
>  
> +#ifdef CONFIG_SYSFS
>  DECLARE_PER_CPU(struct mthp_stat, mthp_stats);
>  
>  static inline void count_mthp_stat(int order, enum mthp_stat_item item)
> @@ -287,6 +288,11 @@ static inline void count_mthp_stat(int order, enum mthp_stat_item item)
>  
>  	this_cpu_inc(mthp_stats.stats[order][item]);
>  }
> +#else
> +static inline void count_mthp_stat(int order, enum mthp_stat_item item)
> +{
> +}
> +#endif
>  
>  #define transparent_hugepage_use_zero_page()				\
>  	(transparent_hugepage_flags &					\
> -- 
> 2.34.1
> 
> 
>