[merged mm-stable] mm-decouple-protnone-helpers-from-config_numa_balancing.patch removed from -mm tree
Andrew Morton <[email protected]> Tue, 04 Aug 2026 19:23:35 -0700
| Newsgroups | org.kernel.vger.mm-commits |
|---|---|
| Message-ID | <[email protected]> |
The quilt patch titled
Subject: mm: decouple protnone helpers from CONFIG_NUMA_BALANCING
has been removed from the -mm tree. Its filename was
mm-decouple-protnone-helpers-from-config_numa_balancing.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: "Kiryl Shutsemau (Meta)" <[email protected]>
Subject: mm: decouple protnone helpers from CONFIG_NUMA_BALANCING
Date: Wed, 8 Jul 2026 12:14:02 +0100
Patch series "userfaultfd: working set tracking for VM guest memory", v10.
This series adds userfaultfd support for tracking the working set of VM
guest memory, so a VMM can identify hot pages and reclaim cold ones to
tiered or remote storage.
This patch (of 15):
pte_protnone() and pmd_protnone() detect present-but-inaccessible page
table entries. This capability is useful beyond NUMA balancing -- for
example, userfaultfd working set tracking uses protnone PTEs to track page
access without unmapping pages.
Introduce CONFIG_ARCH_HAS_PTE_PROTNONE to decouple the protnone PTE
infrastructure from CONFIG_NUMA_BALANCING. The six architectures that
support protnone PTEs (x86_64, arm64, powerpc, s390, riscv, loongarch) now
select this option, and CONFIG_NUMA_BALANCING depends on it.
No functional change -- the same set of architectures continues to have
working protnone support, but the infrastructure is now available
independently of NUMA balancing.
Link: https://lore.kernel.org/[email protected]
Link: https://lore.kernel.org/[email protected]
Signed-off-by: Kiryl Shutsemau (Meta) <[email protected]>
Assisted-by: Claude:claude-opus-4-6
Acked-by: SeongJae Park <[email protected]>
Acked-by: Mike Rapoport (Microsoft) <[email protected]>
Cc: Andrea Arcangeli <[email protected]>
Cc: David Hildenbrand <[email protected]>
Cc: James Houghton <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Liam Howlett <[email protected]>
Cc: Lorenzo Stoakes <[email protected]>
Cc: Paolo Bonzini <[email protected]>
Cc: Peter Xu <[email protected]>
Cc: Sean Christopherson <[email protected]>
Cc: Suren Baghdasaryan <[email protected]>
Cc: Vlastimil Babka <[email protected]>
Cc: Zi Yan <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
---
arch/arm64/Kconfig | 1
arch/arm64/include/asm/pgtable.h | 7 +--
arch/loongarch/Kconfig | 1
arch/loongarch/include/asm/pgtable.h | 4 +-
arch/powerpc/include/asm/book3s/64/pgtable.h | 8 ++--
arch/powerpc/platforms/Kconfig.cputype | 1
arch/riscv/Kconfig | 1
arch/riscv/include/asm/pgtable.h | 7 +--
arch/s390/Kconfig | 1
arch/s390/include/asm/pgtable.h | 4 +-
arch/x86/Kconfig | 1
arch/x86/include/asm/pgtable.h | 8 +---
include/linux/pgtable.h | 32 +++++++++++------
init/Kconfig | 8 ++++
mm/debug_vm_pgtable.c | 4 +-
15 files changed, 52 insertions(+), 36 deletions(-)
--- a/arch/arm64/include/asm/pgtable.h~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/arch/arm64/include/asm/pgtable.h
@@ -553,10 +553,7 @@ static inline pte_t pte_swp_clear_uffd_w
}
#endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */
-#ifdef CONFIG_NUMA_BALANCING
-/*
- * See the comment in include/linux/pgtable.h
- */
+#ifdef CONFIG_ARCH_HAS_PTE_PROTNONE
static inline int pte_protnone(pte_t pte)
{
/*
@@ -575,7 +572,7 @@ static inline int pmd_protnone(pmd_t pmd
{
return pte_protnone(pmd_pte(pmd));
}
-#endif
+#endif /* CONFIG_ARCH_HAS_PTE_PROTNONE */
#define pmd_present(pmd) pte_present(pmd_pte(pmd))
#define pmd_dirty(pmd) pte_dirty(pmd_pte(pmd))
--- a/arch/arm64/Kconfig~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/arch/arm64/Kconfig
@@ -78,6 +78,7 @@ config ARM64
select ARCH_SUPPORTS_CFI
select ARCH_SUPPORTS_ATOMIC_RMW
select ARCH_SUPPORTS_INT128 if CC_HAS_INT128
+ select ARCH_HAS_PTE_PROTNONE
select ARCH_SUPPORTS_NUMA_BALANCING
select ARCH_SUPPORTS_PAGE_TABLE_CHECK
select ARCH_SUPPORTS_PER_VMA_LOCK
--- a/arch/loongarch/include/asm/pgtable.h~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/arch/loongarch/include/asm/pgtable.h
@@ -623,7 +623,7 @@ static inline pmd_t pmdp_huge_get_and_cl
#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
-#ifdef CONFIG_NUMA_BALANCING
+#ifdef CONFIG_ARCH_HAS_PTE_PROTNONE
static inline long pte_protnone(pte_t pte)
{
return (pte_val(pte) & _PAGE_PROTNONE);
@@ -633,7 +633,7 @@ static inline long pmd_protnone(pmd_t pm
{
return (pmd_val(pmd) & _PAGE_PROTNONE);
}
-#endif /* CONFIG_NUMA_BALANCING */
+#endif /* CONFIG_ARCH_HAS_PTE_PROTNONE */
#define pmd_leaf(pmd) ((pmd_val(pmd) & _PAGE_HUGE) != 0)
#define pud_leaf(pud) ((pud_val(pud) & _PAGE_HUGE) != 0)
--- a/arch/loongarch/Kconfig~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/arch/loongarch/Kconfig
@@ -67,6 +67,7 @@ config LOONGARCH
select ARCH_SUPPORTS_LTO_CLANG
select ARCH_SUPPORTS_LTO_CLANG_THIN
select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
+ select ARCH_HAS_PTE_PROTNONE if 64BIT
select ARCH_SUPPORTS_NUMA_BALANCING if NUMA
select ARCH_SUPPORTS_PER_VMA_LOCK
select ARCH_SUPPORTS_RT
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -490,13 +490,13 @@ static inline pte_t pte_clear_soft_dirty
}
#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
-#ifdef CONFIG_NUMA_BALANCING
+#ifdef CONFIG_ARCH_HAS_PTE_PROTNONE
static inline int pte_protnone(pte_t pte)
{
return (pte_raw(pte) & cpu_to_be64(_PAGE_PRESENT | _PAGE_PTE | _PAGE_RWX)) ==
cpu_to_be64(_PAGE_PRESENT | _PAGE_PTE);
}
-#endif /* CONFIG_NUMA_BALANCING */
+#endif /* CONFIG_ARCH_HAS_PTE_PROTNONE */
static inline bool pte_hw_valid(pte_t pte)
{
@@ -1067,12 +1067,12 @@ static inline pte_t *pmdp_ptep(pmd_t *pm
#endif
#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
-#ifdef CONFIG_NUMA_BALANCING
+#ifdef CONFIG_ARCH_HAS_PTE_PROTNONE
static inline int pmd_protnone(pmd_t pmd)
{
return pte_protnone(pmd_pte(pmd));
}
-#endif /* CONFIG_NUMA_BALANCING */
+#endif /* CONFIG_ARCH_HAS_PTE_PROTNONE */
#define pmd_write(pmd) pte_write(pmd_pte(pmd))
--- a/arch/powerpc/platforms/Kconfig.cputype~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/arch/powerpc/platforms/Kconfig.cputype
@@ -87,6 +87,7 @@ config PPC_BOOK3S_64
select ARCH_ENABLE_HUGEPAGE_MIGRATION if HUGETLB_PAGE && MIGRATION
select ARCH_ENABLE_SPLIT_PMD_PTLOCK
select ARCH_SUPPORTS_HUGETLBFS
+ select ARCH_HAS_PTE_PROTNONE
select ARCH_SUPPORTS_NUMA_BALANCING
select HAVE_MOVE_PMD
select HAVE_MOVE_PUD
--- a/arch/riscv/include/asm/pgtable.h~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/arch/riscv/include/asm/pgtable.h
@@ -534,10 +534,7 @@ static inline pte_t pte_swp_clear_soft_d
PAGE_SIZE)
#endif
-#ifdef CONFIG_NUMA_BALANCING
-/*
- * See the comment in include/asm-generic/pgtable.h
- */
+#ifdef CONFIG_ARCH_HAS_PTE_PROTNONE
static inline int pte_protnone(pte_t pte)
{
return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE)) == _PAGE_PROT_NONE;
@@ -547,7 +544,7 @@ static inline int pmd_protnone(pmd_t pmd
{
return pte_protnone(pmd_pte(pmd));
}
-#endif
+#endif /* CONFIG_ARCH_HAS_PTE_PROTNONE */
/* Modify page protection bits */
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
--- a/arch/riscv/Kconfig~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/arch/riscv/Kconfig
@@ -71,6 +71,7 @@ config RISCV
select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS if 64BIT && MMU
select ARCH_SUPPORTS_PAGE_TABLE_CHECK if MMU
select ARCH_SUPPORTS_PER_VMA_LOCK if MMU
+ select ARCH_HAS_PTE_PROTNONE if MMU
select ARCH_SUPPORTS_RT
select ARCH_SUPPORTS_SHADOW_CALL_STACK if HAVE_SHADOW_CALL_STACK
select ARCH_SUPPORTS_SCHED_MC if SMP
--- a/arch/s390/include/asm/pgtable.h~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/arch/s390/include/asm/pgtable.h
@@ -842,7 +842,7 @@ static inline int pte_same(pte_t a, pte_
return pte_val(a) == pte_val(b);
}
-#ifdef CONFIG_NUMA_BALANCING
+#ifdef CONFIG_ARCH_HAS_PTE_PROTNONE
static inline int pte_protnone(pte_t pte)
{
return pte_present(pte) && !(pte_val(pte) & _PAGE_READ);
@@ -853,7 +853,7 @@ static inline int pmd_protnone(pmd_t pmd
/* pmd_leaf(pmd) implies pmd_present(pmd) */
return pmd_leaf(pmd) && !(pmd_val(pmd) & _SEGMENT_ENTRY_READ);
}
-#endif
+#endif /* CONFIG_ARCH_HAS_PTE_PROTNONE */
static inline bool pte_swp_exclusive(pte_t pte)
{
--- a/arch/s390/Kconfig~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/arch/s390/Kconfig
@@ -148,6 +148,7 @@ config S390
select ARCH_SUPPORTS_HUGETLBFS
select ARCH_SUPPORTS_INT128 if CC_HAS_INT128 && CC_IS_CLANG
select ARCH_SUPPORTS_MSEAL_SYSTEM_MAPPINGS
+ select ARCH_HAS_PTE_PROTNONE
select ARCH_SUPPORTS_NUMA_BALANCING
select ARCH_SUPPORTS_PAGE_TABLE_CHECK
select ARCH_SUPPORTS_PER_VMA_LOCK
--- a/arch/x86/include/asm/pgtable.h~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/arch/x86/include/asm/pgtable.h
@@ -985,11 +985,7 @@ static inline int pmd_present(pmd_t pmd)
return pmd_flags(pmd) & (_PAGE_PRESENT | _PAGE_PROTNONE | _PAGE_PSE);
}
-#ifdef CONFIG_NUMA_BALANCING
-/*
- * These work without NUMA balancing but the kernel does not care. See the
- * comment in include/linux/pgtable.h
- */
+#ifdef CONFIG_ARCH_HAS_PTE_PROTNONE
static inline int pte_protnone(pte_t pte)
{
return (pte_flags(pte) & (_PAGE_PROTNONE | _PAGE_PRESENT))
@@ -1001,7 +997,7 @@ static inline int pmd_protnone(pmd_t pmd
return (pmd_flags(pmd) & (_PAGE_PROTNONE | _PAGE_PRESENT))
== _PAGE_PROTNONE;
}
-#endif /* CONFIG_NUMA_BALANCING */
+#endif /* CONFIG_ARCH_HAS_PTE_PROTNONE */
static inline int pmd_none(pmd_t pmd)
{
--- a/arch/x86/Kconfig~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/arch/x86/Kconfig
@@ -124,6 +124,7 @@ config X86
select ARCH_SUPPORTS_DEBUG_PAGEALLOC
select ARCH_SUPPORTS_HUGETLBFS
select ARCH_SUPPORTS_PAGE_TABLE_CHECK if X86_64
+ select ARCH_HAS_PTE_PROTNONE if X86_64
select ARCH_SUPPORTS_NUMA_BALANCING if X86_64
select ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP if NR_CPUS <= 4096
select ARCH_SUPPORTS_CFI if X86_64
--- a/include/linux/pgtable.h~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/include/linux/pgtable.h
@@ -2110,18 +2110,26 @@ static inline int pud_trans_unstable(pud
return 0;
}
-#ifndef CONFIG_NUMA_BALANCING
+#ifndef CONFIG_ARCH_HAS_PTE_PROTNONE
/*
- * In an inaccessible (PROT_NONE) VMA, pte_protnone() may indicate "yes". It is
- * perfectly valid to indicate "no" in that case, which is why our default
- * implementation defaults to "always no".
+ * In an inaccessible (PROT_NONE) VMA, pte_protnone() may indicate "yes". It
+ * is perfectly valid to indicate "no" in that case, which is why our
+ * default implementation defaults to "always no".
*
- * In an accessible VMA, however, pte_protnone() reliably indicates PROT_NONE
- * page protection due to NUMA hinting. NUMA hinting faults only apply in
- * accessible VMAs.
+ * In an accessible VMA, pte_protnone() reliably indicates a present
+ * PROT_NONE page protection. Today the kernel uses such PTEs for two
+ * purposes: NUMA hinting faults, and userfaultfd RWP tracking on
+ * VM_UFFD_RWP VMAs. The two are distinguished by the uffd PTE bit and
+ * the VMA flag; see include/linux/userfaultfd_k.h.
*
- * So, to reliably identify PROT_NONE PTEs that require a NUMA hinting fault,
- * looking at the VMA accessibility is sufficient.
+ * So, to reliably identify PROT_NONE PTEs that require kernel handling,
+ * looking at the VMA accessibility (and the uffd bit on RWP VMAs) is
+ * sufficient.
+ *
+ * Architectures without CONFIG_ARCH_HAS_PTE_PROTNONE get the always-zero
+ * stubs below; PAGE_NONE references that survive to runtime fire the
+ * BUILD_BUG() fallback, since callers should have folded such paths to
+ * dead code via IS_ENABLED(CONFIG_ARCH_HAS_PTE_PROTNONE).
*/
static inline int pte_protnone(pte_t pte)
{
@@ -2132,7 +2140,11 @@ static inline int pmd_protnone(pmd_t pmd
{
return 0;
}
-#endif /* CONFIG_NUMA_BALANCING */
+
+#ifndef PAGE_NONE
+#define PAGE_NONE ({ BUILD_BUG(); (pgprot_t){0}; })
+#endif
+#endif /* CONFIG_ARCH_HAS_PTE_PROTNONE */
#endif /* CONFIG_MMU */
--- a/init/Kconfig~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/init/Kconfig
@@ -948,6 +948,13 @@ config SCHED_PROXY_EXEC
endmenu
#
+# For architectures that support present-but-inaccessible (PROT_NONE) page
+# table entries detectable via pte_protnone() / pmd_protnone():
+#
+config ARCH_HAS_PTE_PROTNONE
+ bool
+
+#
# For architectures that want to enable the support for NUMA-affine scheduler
# balancing logic:
#
@@ -1013,6 +1020,7 @@ config ARCH_WANT_NUMA_VARIABLE_LOCALITY
config NUMA_BALANCING
bool "Memory placement aware NUMA scheduler"
depends on ARCH_SUPPORTS_NUMA_BALANCING
+ depends on ARCH_HAS_PTE_PROTNONE
depends on !ARCH_WANT_NUMA_VARIABLE_LOCALITY
depends on SMP && NUMA_MIGRATION && !PREEMPT_RT
help
--- a/mm/debug_vm_pgtable.c~mm-decouple-protnone-helpers-from-config_numa_balancing
+++ a/mm/debug_vm_pgtable.c
@@ -672,7 +672,7 @@ static void __init pte_protnone_tests(st
{
pte_t pte = pfn_pte(args->fixed_pte_pfn, args->page_prot_none);
- if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
+ if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_PROTNONE))
return;
pr_debug("Validating PTE protnone\n");
@@ -685,7 +685,7 @@ static void __init pmd_protnone_tests(st
{
pmd_t pmd;
- if (!IS_ENABLED(CONFIG_NUMA_BALANCING))
+ if (!IS_ENABLED(CONFIG_ARCH_HAS_PTE_PROTNONE))
return;
if (!has_transparent_hugepage())
_
Patches currently in -mm which might be from [email protected] are
selftests-mm-add-pagemap_scan-test-for-thp-pmd-holes.patch
mm-huge_memory-remove-unused-can_split_folio.patch
mm-huge_memory-fold-split_folio_to_list_to_order-into-split_folio_to_order.patch
mm-fold-userfaultfd_rwp-to-false-without-config_arch_has_pte_protnone.patch