Re: [PATCH] mm/page_vma_mapped: guard check_pmd() with CONFIG_TRANSPARENT_HUGEPAGE

[Wei Yang]

On Wed, Jun 24, 2026 at 01:14:57PM -0700, Andrew Morton wrote:
>On Wed, 24 Jun 2026 08:23:59 +0000 Wei Yang <richard.weiyang@xxxxxxxxx> wrote:
>
>> The kernel test robot reported a build failure on the parisc architecture
>> when expanding HPAGE_PMD_NR in check_pmd().
>> 
>>    mm/page_vma_mapped.c:142:13: note: in expansion of macro 'HPAGE_PMD_NR'
>>      if ((pfn + HPAGE_PMD_NR - 1) < pvmw->pfn)
>>                 ^~~~~~~~~~~~
>> 
>> The config [1] in report link shows neither TRANSPARENT_HUGEPAGE nor
>> HUGETLB_PAGE is defined. Then trigger the BUILD_BUG.
>> 
>> Fix it by define check_pmd() under CONFIG_TRANSPARENT_HUGEPAGE.
>
>hm,
>
>#ifdef CONFIG_PGTABLE_HAS_HUGE_LEAVES
>#define HPAGE_PMD_SHIFT PMD_SHIFT
>#define HPAGE_PUD_SHIFT PUD_SHIFT
>#else
>#define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; })
>#define HPAGE_PUD_SHIFT ({ BUILD_BUG(); 0; })
>#endif
>
>> +#ifdef CONFIG_TRANSPARENT_HUGEPAGE
>>  /* Returns true if the two ranges overlap.  Careful to not overflow. */
>>  static bool check_pmd(unsigned long pfn, struct page_vma_mapped_walk *pvmw)
>>  {
>> @@ -145,6 +146,12 @@ static bool check_pmd(unsigned long pfn, struct page_vma_mapped_walk *pvmw)
>>  		return false;
>>  	return true;
>>  }
>> +#else
>> +static bool check_pmd(unsigned long pfn, struct page_vma_mapped_walk *pvmw)
>> +{
>> +	return false;
>> +}
>> +#endif
>
>I'll leave it to others to decide if this is the most appropriate fix.
>
>Sashiko had an off-topic complaint about the surrounding code:
>	https://lore.kernel.org/oe-kbuild-all/202606240042.ffPsEXVc-lkp@xxxxxxxxx/

I see this robot reply, but not see the Sashiko comment.

How can I view Sashiko's commnet?

-- 
Wei Yang
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