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Diffstat (limited to 'mm/khugepaged.c')
-rw-r--r--mm/khugepaged.c81
1 files changed, 52 insertions, 29 deletions
diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 15203ea7d007..374a6a5193a7 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -347,7 +347,7 @@ struct attribute_group khugepaged_attr_group = {
#endif /* CONFIG_SYSFS */
int hugepage_madvise(struct vm_area_struct *vma,
- unsigned long *vm_flags, int advice)
+ vm_flags_t *vm_flags, int advice)
{
switch (advice) {
case MADV_HUGEPAGE:
@@ -470,7 +470,7 @@ void __khugepaged_enter(struct mm_struct *mm)
}
void khugepaged_enter_vma(struct vm_area_struct *vma,
- unsigned long vm_flags)
+ vm_flags_t vm_flags)
{
if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags) &&
hugepage_pmd_enabled()) {
@@ -700,12 +700,15 @@ static void __collapse_huge_page_copy_succeeded(pte_t *pte,
spinlock_t *ptl,
struct list_head *compound_pagelist)
{
+ unsigned long end = address + HPAGE_PMD_SIZE;
struct folio *src, *tmp;
- pte_t *_pte;
pte_t pteval;
+ pte_t *_pte;
+ unsigned int nr_ptes;
- for (_pte = pte; _pte < pte + HPAGE_PMD_NR;
- _pte++, address += PAGE_SIZE) {
+ for (_pte = pte; _pte < pte + HPAGE_PMD_NR; _pte += nr_ptes,
+ address += nr_ptes * PAGE_SIZE) {
+ nr_ptes = 1;
pteval = ptep_get(_pte);
if (pte_none(pteval) || is_zero_pfn(pte_pfn(pteval))) {
add_mm_counter(vma->vm_mm, MM_ANONPAGES, 1);
@@ -722,18 +725,26 @@ static void __collapse_huge_page_copy_succeeded(pte_t *pte,
struct page *src_page = pte_page(pteval);
src = page_folio(src_page);
- if (!folio_test_large(src))
+
+ if (folio_test_large(src)) {
+ unsigned int max_nr_ptes = (end - address) >> PAGE_SHIFT;
+
+ nr_ptes = folio_pte_batch(src, _pte, pteval, max_nr_ptes);
+ } else {
release_pte_folio(src);
+ }
+
/*
* ptl mostly unnecessary, but preempt has to
* be disabled to update the per-cpu stats
* inside folio_remove_rmap_pte().
*/
spin_lock(ptl);
- ptep_clear(vma->vm_mm, address, _pte);
- folio_remove_rmap_pte(src, src_page, vma);
+ clear_ptes(vma->vm_mm, address, _pte, nr_ptes);
+ folio_remove_rmap_ptes(src, src_page, nr_ptes, vma);
spin_unlock(ptl);
- free_folio_and_swap_cache(src);
+ free_swap_cache(src);
+ folio_put_refs(src, nr_ptes);
}
}
@@ -941,12 +952,18 @@ static inline int check_pmd_state(pmd_t *pmd)
if (pmd_none(pmde))
return SCAN_PMD_NONE;
+
+ /*
+ * The folio may be under migration when khugepaged is trying to
+ * collapse it. Migration success or failure will eventually end
+ * up with a present PMD mapping a folio again.
+ */
+ if (is_pmd_migration_entry(pmde))
+ return SCAN_PMD_MAPPED;
if (!pmd_present(pmde))
return SCAN_PMD_NULL;
if (pmd_trans_huge(pmde))
return SCAN_PMD_MAPPED;
- if (pmd_devmap(pmde))
- return SCAN_PMD_NULL;
if (pmd_bad(pmde))
return SCAN_PMD_NULL;
return SCAN_SUCCEED;
@@ -1486,15 +1503,17 @@ static int set_huge_pmd(struct vm_area_struct *vma, unsigned long addr,
int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
bool install_pmd)
{
+ int nr_mapped_ptes = 0, result = SCAN_FAIL;
+ unsigned int nr_batch_ptes;
struct mmu_notifier_range range;
bool notified = false;
unsigned long haddr = addr & HPAGE_PMD_MASK;
+ unsigned long end = haddr + HPAGE_PMD_SIZE;
struct vm_area_struct *vma = vma_lookup(mm, haddr);
struct folio *folio;
pte_t *start_pte, *pte;
pmd_t *pmd, pgt_pmd;
spinlock_t *pml = NULL, *ptl;
- int nr_ptes = 0, result = SCAN_FAIL;
int i;
mmap_assert_locked(mm);
@@ -1608,11 +1627,15 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
goto abort;
/* step 2: clear page table and adjust rmap */
- for (i = 0, addr = haddr, pte = start_pte;
- i < HPAGE_PMD_NR; i++, addr += PAGE_SIZE, pte++) {
+ for (i = 0, addr = haddr, pte = start_pte; i < HPAGE_PMD_NR;
+ i += nr_batch_ptes, addr += nr_batch_ptes * PAGE_SIZE,
+ pte += nr_batch_ptes) {
+ unsigned int max_nr_batch_ptes = (end - addr) >> PAGE_SHIFT;
struct page *page;
pte_t ptent = ptep_get(pte);
+ nr_batch_ptes = 1;
+
if (pte_none(ptent))
continue;
/*
@@ -1626,26 +1649,29 @@ int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr,
goto abort;
}
page = vm_normal_page(vma, addr, ptent);
+
if (folio_page(folio, i) != page)
goto abort;
+ nr_batch_ptes = folio_pte_batch(folio, pte, ptent, max_nr_batch_ptes);
+
/*
* Must clear entry, or a racing truncate may re-remove it.
* TLB flush can be left until pmdp_collapse_flush() does it.
* PTE dirty? Shmem page is already dirty; file is read-only.
*/
- ptep_clear(mm, addr, pte);
- folio_remove_rmap_pte(folio, page, vma);
- nr_ptes++;
+ clear_ptes(mm, addr, pte, nr_batch_ptes);
+ folio_remove_rmap_ptes(folio, page, nr_batch_ptes, vma);
+ nr_mapped_ptes += nr_batch_ptes;
}
if (!pml)
spin_unlock(ptl);
/* step 3: set proper refcount and mm_counters. */
- if (nr_ptes) {
- folio_ref_sub(folio, nr_ptes);
- add_mm_counter(mm, mm_counter_file(folio), -nr_ptes);
+ if (nr_mapped_ptes) {
+ folio_ref_sub(folio, nr_mapped_ptes);
+ add_mm_counter(mm, mm_counter_file(folio), -nr_mapped_ptes);
}
/* step 4: remove empty page table */
@@ -1678,10 +1704,10 @@ maybe_install_pmd:
: SCAN_SUCCEED;
goto drop_folio;
abort:
- if (nr_ptes) {
+ if (nr_mapped_ptes) {
flush_tlb_mm(mm);
- folio_ref_sub(folio, nr_ptes);
- add_mm_counter(mm, mm_counter_file(folio), -nr_ptes);
+ folio_ref_sub(folio, nr_mapped_ptes);
+ add_mm_counter(mm, mm_counter_file(folio), -nr_mapped_ptes);
}
unlock:
if (start_pte)
@@ -2729,8 +2755,8 @@ static int madvise_collapse_errno(enum scan_result r)
}
}
-int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
- unsigned long start, unsigned long end)
+int madvise_collapse(struct vm_area_struct *vma, unsigned long start,
+ unsigned long end, bool *lock_dropped)
{
struct collapse_control *cc;
struct mm_struct *mm = vma->vm_mm;
@@ -2741,8 +2767,6 @@ int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
BUG_ON(vma->vm_start > start);
BUG_ON(vma->vm_end < end);
- *prev = vma;
-
if (!thp_vma_allowable_order(vma, vma->vm_flags, 0, PMD_ORDER))
return -EINVAL;
@@ -2790,7 +2814,7 @@ int madvise_collapse(struct vm_area_struct *vma, struct vm_area_struct **prev,
&mmap_locked, cc);
}
if (!mmap_locked)
- *prev = NULL; /* Tell caller we dropped mmap_lock */
+ *lock_dropped = true;
handle_result:
switch (result) {
@@ -2800,7 +2824,6 @@ handle_result:
break;
case SCAN_PTE_MAPPED_HUGEPAGE:
BUG_ON(mmap_locked);
- BUG_ON(*prev);
mmap_read_lock(mm);
result = collapse_pte_mapped_thp(mm, addr, true);
mmap_read_unlock(mm);
generated by cgit (git 2.34.1) at 2025-08-05 22:45:38 +0000