[to-be-updated] mm-hugetlb_vmemmap-remove-hugetlb-specific-vmemmap-optimization-macros.patch removed from -mm tree

[to-be-updated] mm-hugetlb_vmemmap-remove-hugetlb-specific-vmemmap-optimization-macros.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm: hugetlb_vmemmap: remove HugeTLB-specific vmemmap optimization macros
has been removed from the -mm tree.  Its filename was
     mm-hugetlb_vmemmap-remove-hugetlb-specific-vmemmap-optimization-macros.patch

This patch was dropped because an updated version will be issued

------------------------------------------------------
From: Muchun Song <muchun.song@linux.dev>
Subject: mm: hugetlb_vmemmap: remove HugeTLB-specific vmemmap optimization macros
Date: Wed, 04 Nov 2026 10:34:59 +0800

Patch series "mm: Decouple folio-based vmemmap optimization from HugeTLB",
v3.

Hi,

Section-based vmemmap optimization is implemented in sparse-vmemmap.c,
while folio-based optimization currently lives in hugetlb_vmemmap.c.  The
latter is tightly coupled to HugeTLB-specific state even though the
underlying page-table remapping operates on one folio at a time.

To make these interfaces easier to maintain, the folio-based remapping
mechanics first need a boundary that is independent of HugeTLB-specific
state and raw address ranges.  This will allow the mechanics to be moved
into a common vmemmap optimization layer alongside the section-based
interface.

This series establishes that boundary through three folio-oriented
operations, each with a distinct role:

  - vmemmap_optimize_folio() optimizes the vmemmap backing of a folio;
  - vmemmap_restore_folio() restores the vmemmap backing of a folio; and
  - vmemmap_pteify_folio() converts the vmemmap backing of a folio to
    PTE mappings.

Together, these operations encapsulate the address-range calculation and
remapping mechanics for a folio.  HugeTLB wrappers retain policy decisions
such as eligibility, optimized state, batching and TLB flush handling.

Patches 1-8 generalize the underlying vmemmap remapping infrastructure by
removing HugeTLB-specific assumptions and simplifying remap control and
resource handling.  Patches 9-12 then establish folio-oriented operations
for optimization, restoration and PTE conversion.

The implementation remains in hugetlb_vmemmap.c for now.  A follow-up can
move the folio-based operations into the common vmemmap optimization layer
once the interface boundary is in place.


This patch (of 12):

Vmemmap optimization is no longer HugeTLB-specific, so the remaining
HugeTLB-local reserve macros are redundant.

Replace them with the generic definitions to remove duplication and keep
the HugeTLB vmemmap code aligned with the common optimization macros.

Link: https://lore.kernel.org/20261104023510.260766-1-songmuchun@bytedance.com
Link: https://lore.kernel.org/20261104023510.260766-2-songmuchun@bytedance.com
Signed-off-by: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Qi Zheng <qi.zheng@linux.dev>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Tested-by: Andrew Morton <akpm@linux-foundation.org>
  Link: https://lore.kernel.org/20261103224659.2865b9ff27d09994949edd78@linux-foundation.org
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: James Houghton <jthoughton@google.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Huacai Chen <chenhuacai@kernel.org>
---

 include/linux/vmemmap-optimization.h |    4 ++--
 mm/hugetlb.c                         |    4 ++--
 mm/hugetlb_vmemmap.c                 |    6 +++---
 mm/hugetlb_vmemmap.h                 |   10 ++--------
 4 files changed, 9 insertions(+), 15 deletions(-)

--- a/include/linux/vmemmap-optimization.h~mm-hugetlb_vmemmap-remove-hugetlb-specific-vmemmap-optimization-macros
+++ a/include/linux/vmemmap-optimization.h
@@ -27,8 +27,8 @@
 
 /* The number of retained vmemmap pages with HVO enabled. */
 #define VMEMMAP_OPTIMIZATION_PAGES		1
-#define VMEMMAP_OPTIMIZATION_NR_STRUCT_PAGES	\
-	(VMEMMAP_OPTIMIZATION_PAGES * PAGE_SIZE / sizeof(struct page))
+#define VMEMMAP_OPTIMIZATION_SIZE		(VMEMMAP_OPTIMIZATION_PAGES * PAGE_SIZE)
+#define VMEMMAP_OPTIMIZATION_NR_STRUCT_PAGES	(VMEMMAP_OPTIMIZATION_SIZE / sizeof(struct page))
 #define VMEMMAP_OPTIMIZATION_MIN_ORDER		(ilog2(VMEMMAP_OPTIMIZATION_NR_STRUCT_PAGES) + 1)
 
 #ifdef CONFIG_VMEMMAP_OPTIMIZATION
--- a/mm/hugetlb.c~mm-hugetlb_vmemmap-remove-hugetlb-specific-vmemmap-optimization-macros
+++ a/mm/hugetlb.c
@@ -3317,7 +3317,7 @@ static void __init prep_and_add_bootmem_
 			 * be no contention.
 			 */
 			hugetlb_folio_init_tail_vmemmap(folio, h,
-					HUGETLB_VMEMMAP_RESERVE_PAGES,
+					VMEMMAP_OPTIMIZATION_NR_STRUCT_PAGES,
 					pages_per_huge_page(h));
 		}
 		hugetlb_bootmem_init_migratetype(folio, h);
@@ -3357,7 +3357,7 @@ static void __init gather_bootmem_preall
 		WARN_ON(folio_ref_count(folio) != 1);
 
 		hugetlb_folio_init_vmemmap(folio, h,
-					   HUGETLB_VMEMMAP_RESERVE_PAGES);
+					   VMEMMAP_OPTIMIZATION_NR_STRUCT_PAGES);
 		init_new_hugetlb_folio(folio);
 
 		if (vmemmap_optimizable_order(pfn_to_section_compound_order(pfn)))
--- a/mm/hugetlb_vmemmap.c~mm-hugetlb_vmemmap-remove-hugetlb-specific-vmemmap-optimization-macros
+++ a/mm/hugetlb_vmemmap.c
@@ -408,7 +408,7 @@ static int __hugetlb_vmemmap_restore_fol
 	vmemmap_start	= (unsigned long)&folio->page;
 	vmemmap_end	= vmemmap_start + hugetlb_vmemmap_size(h);
 
-	vmemmap_start	+= HUGETLB_VMEMMAP_RESERVE_SIZE;
+	vmemmap_start	+= VMEMMAP_OPTIMIZATION_SIZE;
 
 	/*
 	 * The pages which the vmemmap virtual address range [@vmemmap_start,
@@ -676,8 +676,8 @@ static int __init hugetlb_vmemmap_init(v
 {
 	const struct hstate *h;
 
-	/* HUGETLB_VMEMMAP_RESERVE_SIZE should cover all used struct pages */
-	BUILD_BUG_ON(__NR_USED_SUBPAGE > HUGETLB_VMEMMAP_RESERVE_PAGES);
+	/* VMEMMAP_OPTIMIZATION_NR_STRUCT_PAGES should cover all used struct pages */
+	BUILD_BUG_ON(__NR_USED_SUBPAGE > VMEMMAP_OPTIMIZATION_NR_STRUCT_PAGES);
 
 	for_each_hstate(h) {
 		if (hugetlb_vmemmap_optimizable(h)) {
--- a/mm/hugetlb_vmemmap.h~mm-hugetlb_vmemmap-remove-hugetlb-specific-vmemmap-optimization-macros
+++ a/mm/hugetlb_vmemmap.h
@@ -9,13 +9,7 @@
 #ifndef _LINUX_HUGETLB_VMEMMAP_H
 #define _LINUX_HUGETLB_VMEMMAP_H
 #include <linux/hugetlb.h>
-
-/*
- * Reserve one vmemmap page, all vmemmap addresses are mapped to it. See
- * Documentation/mm/vmemmap_dedup.rst.
- */
-#define HUGETLB_VMEMMAP_RESERVE_SIZE	PAGE_SIZE
-#define HUGETLB_VMEMMAP_RESERVE_PAGES	(HUGETLB_VMEMMAP_RESERVE_SIZE / sizeof(struct page))
+#include <linux/vmemmap-optimization.h>
 
 #ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP
 int hugetlb_vmemmap_restore_folio(const struct hstate *h, struct folio *folio);
@@ -37,7 +31,7 @@ static inline unsigned int hugetlb_vmemm
  */
 static inline unsigned int hugetlb_vmemmap_optimizable_size(const struct hstate *h)
 {
-	int size = hugetlb_vmemmap_size(h) - HUGETLB_VMEMMAP_RESERVE_SIZE;
+	int size = hugetlb_vmemmap_size(h) - VMEMMAP_OPTIMIZATION_SIZE;
 
 	if (!is_power_of_2(sizeof(struct page)))
 		return 0;
_

Patches currently in -mm which might be from muchun.song@linux.dev are

mm-fix-missing-page-table-destructor-in-pagetable_free.patch
riscv-mm-fix-hotplug-page-table-destructor-handling.patch
riscv-mm-fix-missing-destructor-for-hotplug-pud-tables.patch
arm64-mm-fix-destructor-for-unconstructed-hotplug-page-tables.patch
mm-sparse-vmemmap-map-shared-vmemmap-tail-pages-as-read-only.patch
powerpc-mm-map-shared-vmemmap-tail-pages-as-read-only.patch
mm-hugetlb_vmemmap-remove-vmemmap_wrprotect_hvo.patch
mm-hugetlb_vmemmap-remove-hugetlb_vmemmap_optimize_bootmem_folios.patch
mm-generalize-kernel-pte-table-allocation.patch
mm-generalize-pmd-page-table-allocation.patch
mm-generalize-pud-page-table-allocation.patch
mm-remove-pagetable_dtor_free.patch
mm-remove-redundant-pagetable_dtor-calls.patch
mm-hugetlb_vmemmap-unify-vmemmap_splitremap_no_tlb_flush.patch
mm-hugetlb_vmemmap-simplify-vmemmap-head-page-handling.patch
mm-hugetlb_vmemmap-generalize-vmemmap-page-allocation.patch
mm-hugetlb_vmemmap-unify-writable-vmemmap-page-preparation.patch
mm-hugetlb_vmemmap-rename-vmemmap_remap_pte-to-vmemmap_optimize_pte.patch
mm-hugetlb_vmemmap-simplify-shared-tail-page-handling.patch
mm-hugetlb_vmemmap-move-alloc_vmemmap_page_list-next-to-its-free-helper.patch
mm-hugetlb_vmemmap-make-vmemmap-optimization-folio-oriented.patch
mm-hugetlb_vmemmap-make-vmemmap-restoration-folio-oriented.patch
mm-hugetlb_vmemmap-unify-vmemmap-range-restoration.patch
mm-hugetlb_vmemmap-make-vmemmap-pte-conversion-folio-oriented.patch
mm-hugetlb-fix-validation-of-unsupported-hugetlb-orders.patch