The patch titled Subject: Revert "mm: fix MAX_FOLIO_ORDER on powerpc configs with hugetlb" has been added to the -mm mm-hotfixes-unstable branch. Its filename is revert-mm-fix-max_folio_order-on-powerpc-configs-with-hugetlb.patch

This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...

This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------ From: Shuah Khan skhan@linuxfoundation.org Subject: Revert "mm: fix MAX_FOLIO_ORDER on powerpc configs with hugetlb" Date: Wed, 3 Dec 2025 19:33:56 -0700

This reverts commit 39231e8d6ba7f794b566fd91ebd88c0834a23b98.

Enabling HAVE_GIGANTIC_FOLIOS broke kernel build and git clone on two systems. git fetch-pack fails when cloning large repos and make hangs or errors out of Makefile.build with Error: 139. These failures are random with git clone failing after fetching 1% of the objects, and make hangs while compiling random files.

Below is is one of the git clone failures:

git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git linux_6.19 Cloning into 'linux_6.19'... remote: Enumerating objects: 11173575, done. remote: Counting objects: 100% (785/785), done. remote: Compressing objects: 100% (373/373), done. remote: Total 11173575 (delta 534), reused 505 (delta 411), pack-reused 11172790 (from 1) Receiving objects: 100% (11173575/11173575), 3.00 GiB | 7.08 MiB/s, done. Resolving deltas: 100% (9195212/9195212), done. fatal: did not receive expected object 0002003e951b5057c16de5a39140abcbf6e44e50 fatal: fetch-pack: invalid index-pack output

(akpm: reverting this probably just hides a bug, but let's do that for now while the bug is being worked on).

Link: https://lkml.kernel.org/r/20251204023358.54107-1-skhan@linuxfoundation.org Fixes: 39231e8d6ba7 ("mm: fix MAX_FOLIO_ORDER on powerpc configs with hugetlb") Signed-off-by: Shuah Khan skhan@linuxfoundation.org Cc: Christophe Leroy christophe.leroy@csgroup.eu Cc: Liam Howlett liam.howlett@oracle.com Cc: Lorenzo Stoakes lorenzo.stoakes@oracle.com Cc: Madhavan Srinivasan maddy@linux.ibm.com Cc: Masahiro Yamada masahiroy@kernel.org Cc: Michael Ellerman mpe@ellerman.id.au Cc: Michal Hocko mhocko@suse.com Cc: Mike Rapoport rppt@kernel.org Cc: Nicholas Piggin npiggin@gmail.com Cc: Suren Baghdasaryan surenb@google.com Cc: Vlastimil Babka vbabka@suse.cz Cc: Linus Torvalds torvalds@linuxfoundation.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

arch/powerpc/Kconfig | 1 - arch/powerpc/platforms/Kconfig.cputype | 1 + include/linux/mm.h | 13 +++---------- mm/Kconfig | 7 ------- 4 files changed, 4 insertions(+), 18 deletions(-)

--- a/arch/powerpc/Kconfig~revert-mm-fix-max_folio_order-on-powerpc-configs-with-hugetlb +++ a/arch/powerpc/Kconfig @@ -137,7 +137,6 @@ config PPC select ARCH_HAS_DMA_OPS if PPC64 select ARCH_HAS_FORTIFY_SOURCE select ARCH_HAS_GCOV_PROFILE_ALL - select ARCH_HAS_GIGANTIC_PAGE if ARCH_SUPPORTS_HUGETLBFS select ARCH_HAS_KCOV select ARCH_HAS_KERNEL_FPU_SUPPORT if PPC64 && PPC_FPU select ARCH_HAS_MEMBARRIER_CALLBACKS --- a/arch/powerpc/platforms/Kconfig.cputype~revert-mm-fix-max_folio_order-on-powerpc-configs-with-hugetlb +++ a/arch/powerpc/platforms/Kconfig.cputype @@ -423,6 +423,7 @@ config PPC_64S_HASH_MMU config PPC_RADIX_MMU bool "Radix MMU Support" depends on PPC_BOOK3S_64 + select ARCH_HAS_GIGANTIC_PAGE default y help Enable support for the Power ISA 3.0 Radix style MMU. Currently this --- a/include/linux/mm.h~revert-mm-fix-max_folio_order-on-powerpc-configs-with-hugetlb +++ a/include/linux/mm.h @@ -2074,7 +2074,7 @@ static inline unsigned long folio_nr_pag return folio_large_nr_pages(folio); }

-#if !defined(CONFIG_HAVE_GIGANTIC_FOLIOS) +#if !defined(CONFIG_ARCH_HAS_GIGANTIC_PAGE) /* * We don't expect any folios that exceed buddy sizes (and consequently * memory sections). @@ -2087,17 +2087,10 @@ static inline unsigned long folio_nr_pag * pages are guaranteed to be contiguous. */ #define MAX_FOLIO_ORDER PFN_SECTION_SHIFT -#elif defined(CONFIG_HUGETLB_PAGE) -/* - * There is no real limit on the folio size. We limit them to the maximum we - * currently expect (see CONFIG_HAVE_GIGANTIC_FOLIOS): with hugetlb, we expect - * no folios larger than 16 GiB on 64bit and 1 GiB on 32bit. - */ -#define MAX_FOLIO_ORDER get_order(IS_ENABLED(CONFIG_64BIT) ? SZ_16G : SZ_1G) #else /* - * Without hugetlb, gigantic folios that are bigger than a single PUD are - * currently impossible. + * There is no real limit on the folio size. We limit them to the maximum we + * currently expect (e.g., hugetlb, dax). */ #define MAX_FOLIO_ORDER PUD_ORDER #endif --- a/mm/Kconfig~revert-mm-fix-max_folio_order-on-powerpc-configs-with-hugetlb +++ a/mm/Kconfig @@ -908,13 +908,6 @@ config PAGE_MAPCOUNT config PGTABLE_HAS_HUGE_LEAVES def_bool TRANSPARENT_HUGEPAGE || HUGETLB_PAGE

-# -# We can end up creating gigantic folio. -# -config HAVE_GIGANTIC_FOLIOS - def_bool (HUGETLB_PAGE && ARCH_HAS_GIGANTIC_PAGE) || \ - (ZONE_DEVICE && HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD) - # TODO: Allow to be enabled without THP config ARCH_SUPPORTS_HUGE_PFNMAP def_bool n _

Patches currently in -mm which might be from skhan@linuxfoundation.org are

revert-mm-fix-max_folio_order-on-powerpc-configs-with-hugetlb.patch