The patch titled
Subject: mm: do_zap_pte_range: return any_skipped information to the caller
has been added to the -mm mm-unstable branch. Its filename is
mm-do_zap_pte_range-return-any_skipped-information-to-the-caller.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-do_zap_pte_range-return-any_skipped-information-to-the-caller.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: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Subject: mm: do_zap_pte_range: return any_skipped information to the caller
Date: Wed, 4 Dec 2024 19:09:47 +0800
Let the caller of do_zap_pte_range() know whether we skip zap ptes or
reinstall uffd-wp ptes through any_skipped parameter, so that subsequent
commits can use this information in zap_pte_range() to detect whether the
PTE page can be reclaimed.
Link: https://lkml.kernel.org/r/59f33ec9f74e9f058ed319b0bfadd76b0f7adf9b.1733305182.git.zhengqi.arch@xxxxxxxxxxxxx
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: David Hildenbrand <david@xxxxxxxxxx>
Cc: David Rientjes <rientjes@xxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jann Horn <jannh@xxxxxxxxxx>
Cc: Lorenzo Stoakes <lorenzo.stoakes@xxxxxxxxxx>
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Cc: Muchun Song <muchun.song@xxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Zach O'Keefe <zokeefe@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memory.c | 36 +++++++++++++++++++++---------------
1 file changed, 21 insertions(+), 15 deletions(-)
--- a/mm/memory.c~mm-do_zap_pte_range-return-any_skipped-information-to-the-caller
+++ a/mm/memory.c
@@ -1501,7 +1501,7 @@ static __always_inline void zap_present_
struct vm_area_struct *vma, struct folio *folio,
struct page *page, pte_t *pte, pte_t ptent, unsigned int nr,
unsigned long addr, struct zap_details *details, int *rss,
- bool *force_flush, bool *force_break)
+ bool *force_flush, bool *force_break, bool *any_skipped)
{
struct mm_struct *mm = tlb->mm;
bool delay_rmap = false;
@@ -1527,8 +1527,8 @@ static __always_inline void zap_present_
arch_check_zapped_pte(vma, ptent);
tlb_remove_tlb_entries(tlb, pte, nr, addr);
if (unlikely(userfaultfd_pte_wp(vma, ptent)))
- zap_install_uffd_wp_if_needed(vma, addr, pte, nr, details,
- ptent);
+ *any_skipped = zap_install_uffd_wp_if_needed(vma, addr, pte,
+ nr, details, ptent);
if (!delay_rmap) {
folio_remove_rmap_ptes(folio, page, nr, vma);
@@ -1552,7 +1552,7 @@ static inline int zap_present_ptes(struc
struct vm_area_struct *vma, pte_t *pte, pte_t ptent,
unsigned int max_nr, unsigned long addr,
struct zap_details *details, int *rss, bool *force_flush,
- bool *force_break)
+ bool *force_break, bool *any_skipped)
{
const fpb_t fpb_flags = FPB_IGNORE_DIRTY | FPB_IGNORE_SOFT_DIRTY;
struct mm_struct *mm = tlb->mm;
@@ -1567,15 +1567,17 @@ static inline int zap_present_ptes(struc
arch_check_zapped_pte(vma, ptent);
tlb_remove_tlb_entry(tlb, pte, addr);
if (userfaultfd_pte_wp(vma, ptent))
- zap_install_uffd_wp_if_needed(vma, addr, pte, 1,
- details, ptent);
+ *any_skipped = zap_install_uffd_wp_if_needed(vma, addr,
+ pte, 1, details, ptent);
ksm_might_unmap_zero_page(mm, ptent);
return 1;
}
folio = page_folio(page);
- if (unlikely(!should_zap_folio(details, folio)))
+ if (unlikely(!should_zap_folio(details, folio))) {
+ *any_skipped = true;
return 1;
+ }
/*
* Make sure that the common "small folio" case is as fast as possible
@@ -1587,22 +1589,23 @@ static inline int zap_present_ptes(struc
zap_present_folio_ptes(tlb, vma, folio, page, pte, ptent, nr,
addr, details, rss, force_flush,
- force_break);
+ force_break, any_skipped);
return nr;
}
zap_present_folio_ptes(tlb, vma, folio, page, pte, ptent, 1, addr,
- details, rss, force_flush, force_break);
+ details, rss, force_flush, force_break, any_skipped);
return 1;
}
static inline int zap_nonpresent_ptes(struct mmu_gather *tlb,
struct vm_area_struct *vma, pte_t *pte, pte_t ptent,
unsigned int max_nr, unsigned long addr,
- struct zap_details *details, int *rss)
+ struct zap_details *details, int *rss, bool *any_skipped)
{
swp_entry_t entry;
int nr = 1;
+ *any_skipped = true;
entry = pte_to_swp_entry(ptent);
if (is_device_private_entry(entry) ||
is_device_exclusive_entry(entry)) {
@@ -1660,7 +1663,7 @@ static inline int zap_nonpresent_ptes(st
WARN_ON_ONCE(1);
}
clear_not_present_full_ptes(vma->vm_mm, addr, pte, nr, tlb->fullmm);
- zap_install_uffd_wp_if_needed(vma, addr, pte, nr, details, ptent);
+ *any_skipped = zap_install_uffd_wp_if_needed(vma, addr, pte, nr, details, ptent);
return nr;
}
@@ -1669,7 +1672,8 @@ static inline int do_zap_pte_range(struc
struct vm_area_struct *vma, pte_t *pte,
unsigned long addr, unsigned long end,
struct zap_details *details, int *rss,
- bool *force_flush, bool *force_break)
+ bool *force_flush, bool *force_break,
+ bool *any_skipped)
{
pte_t ptent = ptep_get(pte);
int max_nr = (end - addr) / PAGE_SIZE;
@@ -1691,10 +1695,11 @@ static inline int do_zap_pte_range(struc
if (pte_present(ptent))
nr += zap_present_ptes(tlb, vma, pte, ptent, max_nr, addr,
- details, rss, force_flush, force_break);
+ details, rss, force_flush, force_break,
+ any_skipped);
else
nr += zap_nonpresent_ptes(tlb, vma, pte, ptent, max_nr, addr,
- details, rss);
+ details, rss, any_skipped);
return nr;
}
@@ -1705,6 +1710,7 @@ static unsigned long zap_pte_range(struc
struct zap_details *details)
{
bool force_flush = false, force_break = false;
+ bool any_skipped = false;
struct mm_struct *mm = tlb->mm;
int rss[NR_MM_COUNTERS];
spinlock_t *ptl;
@@ -1725,7 +1731,7 @@ static unsigned long zap_pte_range(struc
break;
nr = do_zap_pte_range(tlb, vma, pte, addr, end, details, rss,
- &force_flush, &force_break);
+ &force_flush, &force_break, &any_skipped);
if (unlikely(force_break)) {
addr += nr * PAGE_SIZE;
break;
_
Patches currently in -mm which might be from zhengqi.arch@xxxxxxxxxxxxx are
mm-pgtable-make-ptep_clear-non-atomic.patch
mm-khugepaged-recheck-pmd-state-in-retract_page_tables.patch
mm-userfaultfd-recheck-dst_pmd-entry-in-move_pages_pte.patch
mm-introduce-zap_nonpresent_ptes.patch
mm-introduce-do_zap_pte_range.patch
mm-skip-over-all-consecutive-none-ptes-in-do_zap_pte_range.patch
mm-zap_install_uffd_wp_if_needed-return-whether-uffd-wp-pte-has-been-re-installed.patch
mm-do_zap_pte_range-return-any_skipped-information-to-the-caller.patch
mm-make-zap_pte_range-handle-full-within-pmd-range.patch
mm-pgtable-reclaim-empty-pte-page-in-madvisemadv_dontneed.patch
x86-mm-free-page-table-pages-by-rcu-instead-of-semi-rcu.patch
x86-select-arch_supports_pt_reclaim-if-x86_64.patch
