Re: linux-next: build failure after merge of the mm-hotfixes tree

Stephen Rothwell
2025-05-29T00:03:20Z

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Hi all,

On Thu, 29 May 2025 09:59:38 +1000 Stephen Rothwell <sfr@canb.auug.org.au> wrote:

>
> After merging the mm-hotfixes tree, today's linux-next build (powerpc
> ppc64_defconfig) failed like this:
>
> mm/khugepaged.c: In function 'hpage_collapse_scan_file':
> mm/khugepaged.c:2337:21: error: implicit declaration of function 'folio_expected_ref_count' [-Wimplicit-function-declaration]
> 2337 | if (folio_expected_ref_count(folio) + 1 != folio_ref_count(folio)) {
> | ^~~~~~~~~~~~~~~~~~~~~~~~
>
> Caused by commit
>
> 3bdddbba5f02 ("mm/khugepaged: fix race with folio split/free using temporary reference")
>
> I have reverted that commit for today.

folio_expected_ref_count() is not introduced until commit

86ebd50224c0 ("mm: add folio_expected_ref_count() for reference count calculation")

in the mm-stable tree.

--
Cheers,
Stephen Rothwell

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