+ mm-kconfig-make-flatmem-depend-on-numa.patch added to mm-new branch

Andrew Morton <[email protected]> Tue, 04 Aug 2026 10:53:52 -0700
Newsgroups org.kernel.vger.mm-commits
Message-ID <[email protected]>
The patch titled
     Subject: mm/Kconfig: make FLATMEM depend on !NUMA
has been added to the -mm mm-new branch.  Its filename is
     mm-kconfig-make-flatmem-depend-on-numa.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-kconfig-make-flatmem-depend-on-numa.patch

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

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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------------------------------------------------------
From: Sang-Heon Jeon <[email protected]>
Subject: mm/Kconfig: make FLATMEM depend on !NUMA
Date: Wed, 5 Aug 2026 00:11:41 +0900

Patch series "mm/page_ext: remove pgdat_page_ext_init()", v2.

pgdat_page_ext_init() has no effect on FLATMEM. The pgdat is always
the zero-initialized contig_page_data, because no architecture
supports FLATMEM + NUMA.

That constraint is only implicit in the arch Kconfig files. So patch 1
makes it explicit in mm/Kconfig, and patch 2 removes pgdat_page_ext_init().

No functional change.


This patch (of 2):

FLATMEM + NUMA is not supported by any architecture and fails to build. 
The constraint is only implicit in the arch Kconfig files.

So make it explicit in mm/Kconfig.

No functional change.

Link: https://lore.kernel.org/[email protected]
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Sang-Heon Jeon <[email protected]>
Suggested-by: Zi Yan <[email protected]>
Acked-by: Zi Yan <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Liam R. Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Mike Rapoport <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---

 mm/Kconfig |    2 ++
 1 file changed, 2 insertions(+)

--- a/mm/Kconfig~mm-kconfig-make-flatmem-depend-on-numa
+++ a/mm/Kconfig
@@ -390,6 +390,7 @@ choice
 
 config FLATMEM_MANUAL
 	bool "Flat Memory"
+	depends on !NUMA
 	depends on !ARCH_SPARSEMEM_ENABLE || ARCH_FLATMEM_ENABLE
 	help
 	  This option is best suited for non-NUMA systems with
@@ -424,6 +425,7 @@ config SPARSEMEM
 
 config FLATMEM
 	def_bool y
+	depends on !NUMA
 	depends on !SPARSEMEM || FLATMEM_MANUAL
 
 #
_

Patches currently in -mm which might be from [email protected] are

mm-early_ioremap-clarify-early_ioremap_reset-semantics.patch
riscv-remove-unused-__late_set_fixmap-and-__late_clear_fixmap.patch
arm64-remove-early_ioremap_reset-call-and-__late_-macros.patch
mm-sparse-correct-init-section-annotations.patch
mm-kconfig-make-flatmem-depend-on-numa.patch
mm-page_ext-remove-pgdat_page_ext_init.patch