The patch titled
Subject: mm: introduce ctor/dtor at PGD level
has been added to the -mm mm-unstable branch. Its filename is
mm-introduce-ctor-dtor-at-pgd-level.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-introduce-ctor-dtor-at-pgd-level.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Kevin Brodsky <kevin.brodsky@xxxxxxx>
Subject: mm: introduce ctor/dtor at PGD level
Date: Fri, 3 Jan 2025 18:44:15 +0000
Following on from the introduction of P4D-level ctor/dtor, let's finish
the job and introduce ctor/dtor at PGD level. The incurred improvement in
page accounting is minimal - the main motivation is to create a single,
generic place where construction/destruction hooks can be added for all
page table pages.
This patch should cover all architectures and all configurations where
PGDs are one or more regular pages. This excludes any configuration where
PGDs are allocated from a kmem_cache object.
Link: https://lkml.kernel.org/r/20250103184415.2744423-7-kevin.brodsky@xxxxxxx
Signed-off-by: Kevin Brodsky <kevin.brodsky@xxxxxxx>
Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Cc: Mike Rapoport (Microsoft) <rppt@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Cc: Ryan Roberts <ryan.roberts@xxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
arch/m68k/include/asm/mcf_pgalloc.h | 3 ++-
arch/m68k/mm/motorola.c | 6 ++++--
arch/s390/include/asm/pgalloc.h | 9 ++++++++-
include/asm-generic/pgalloc.h | 3 ++-
include/linux/mm.h | 5 +++++
5 files changed, 21 insertions(+), 5 deletions(-)
--- a/arch/m68k/include/asm/mcf_pgalloc.h~mm-introduce-ctor-dtor-at-pgd-level
+++ a/arch/m68k/include/asm/mcf_pgalloc.h
@@ -73,7 +73,7 @@ static inline void pte_free(struct mm_st
static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
- pagetable_free(virt_to_ptdesc(pgd));
+ pagetable_dtor_free(virt_to_ptdesc(pgd));
}
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
@@ -84,6 +84,7 @@ static inline pgd_t *pgd_alloc(struct mm
if (!ptdesc)
return NULL;
+ pagetable_pgd_ctor(ptdesc);
new_pgd = ptdesc_address(ptdesc);
memcpy(new_pgd, swapper_pg_dir, PTRS_PER_PGD * sizeof(pgd_t));
--- a/arch/m68k/mm/motorola.c~mm-introduce-ctor-dtor-at-pgd-level
+++ a/arch/m68k/mm/motorola.c
@@ -169,6 +169,9 @@ void *get_pointer_table(int type)
case TABLE_PMD:
pagetable_pmd_ctor(virt_to_ptdesc(page));
break;
+ case TABLE_PGD:
+ pagetable_pgd_ctor(virt_to_ptdesc(page));
+ break;
}
mmu_page_ctor(page);
@@ -207,8 +210,7 @@ int free_pointer_table(void *table, int
/* all tables in page are free, free page */
list_del(dp);
mmu_page_dtor((void *)page);
- if (type == TABLE_PTE || type == TABLE_PMD)
- pagetable_dtor(virt_to_ptdesc((void *)page));
+ pagetable_dtor(virt_to_ptdesc((void *)page));
free_page (page);
return 1;
} else if (ptable_list[type].next != dp) {
--- a/arch/s390/include/asm/pgalloc.h~mm-introduce-ctor-dtor-at-pgd-level
+++ a/arch/s390/include/asm/pgalloc.h
@@ -130,11 +130,18 @@ static inline void pud_populate(struct m
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
- return (pgd_t *) crst_table_alloc(mm);
+ unsigned long *table = crst_table_alloc(mm);
+
+ if (!table)
+ return NULL;
+ pagetable_pgd_ctor(virt_to_ptdesc(table));
+
+ return (pgd_t *) table;
}
static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
{
+ pagetable_dtor(virt_to_ptdesc(pgd));
crst_table_free(mm, (unsigned long *) pgd);
}
--- a/include/asm-generic/pgalloc.h~mm-introduce-ctor-dtor-at-pgd-level
+++ a/include/asm-generic/pgalloc.h
@@ -271,6 +271,7 @@ static inline pgd_t *__pgd_alloc_noprof(
if (!ptdesc)
return NULL;
+ pagetable_pgd_ctor(ptdesc);
return ptdesc_address(ptdesc);
}
#define __pgd_alloc(...) alloc_hooks(__pgd_alloc_noprof(__VA_ARGS__))
@@ -280,7 +281,7 @@ static inline void __pgd_free(struct mm_
struct ptdesc *ptdesc = virt_to_ptdesc(pgd);
BUG_ON((unsigned long)pgd & (PAGE_SIZE-1));
- pagetable_free(ptdesc);
+ pagetable_dtor_free(ptdesc);
}
#ifndef __HAVE_ARCH_PGD_FREE
--- a/include/linux/mm.h~mm-introduce-ctor-dtor-at-pgd-level
+++ a/include/linux/mm.h
@@ -3243,6 +3243,11 @@ static inline void pagetable_p4d_ctor(st
__pagetable_ctor(ptdesc);
}
+static inline void pagetable_pgd_ctor(struct ptdesc *ptdesc)
+{
+ __pagetable_ctor(ptdesc);
+}
+
extern void __init pagecache_init(void);
extern void free_initmem(void);
_
Patches currently in -mm which might be from kevin.brodsky@xxxxxxx are
selftests-mm-fix-condition-in-uffd_move_test_common.patch
selftests-mm-fix-wmaybe-uninitialized-warnings.patch
selftests-mm-fix-strncpy-length.patch
selftests-mm-fix-warray-bounds-warnings-in-pkey_sighandler_tests.patch
selftests-mm-fix-warray-bounds-warnings-in-pkey_sighandler_tests-fix.patch
selftests-mm-build-with-o2.patch
selftests-mm-remove-unused-pkey-helpers.patch
selftests-mm-define-types-using-typedef-in-pkey-helpersh.patch
selftests-mm-ensure-pkey-h-define-inline-functions-only.patch
selftests-mm-remove-empty-pkey-helper-definition.patch
selftests-mm-ensure-non-global-pkey-symbols-are-marked-static.patch
selftests-mm-use-sys_pkey-helpers-consistently.patch
selftests-mm-use-sys_pkey-helpers-consistently-fix.patch
selftests-mm-rename-pkey-register-macro.patch
selftests-mm-skip-pkey_sighandler_tests-if-support-is-missing.patch
selftests-mm-remove-x-permission-from-sigaltstack-mapping.patch
riscv-mm-skip-pgtable-level-check-in-pudp4d_alloc_one.patch
asm-generic-pgalloc-provide-generic-p4d_alloc_onefree.patch
mm-move-common-part-of-pagetable__ctor-to-helper.patch
parisc-mm-ensure-pagetable_pmd_tor-are-called.patch
m68k-mm-add-calls-to-pagetable_pmd_tor.patch
arm-mm-rename-pgd-helpers.patch
asm-generic-pgalloc-provide-generic-__pgd_allocfree.patch
mm-introduce-ctor-dtor-at-pgd-level.patch
