Rearrange code in mm/huge_memory.c to make future changes somewhat
easier.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 223 +++++++++++++++++++++++++++----------------------------
1 file changed, 111 insertions(+), 112 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 8efe27b86370..52973809777f 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1600,6 +1600,117 @@ unlock:
return NULL;
}
+static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
+ unsigned long haddr, pmd_t *pmd)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ pgtable_t pgtable;
+ pmd_t _pmd;
+ int i;
+
+ pmdp_clear_flush(vma, haddr, pmd);
+ /* leave pmd empty until pte is filled */
+
+ pgtable = pgtable_trans_huge_withdraw(mm, pmd);
+ pmd_populate(mm, &_pmd, pgtable);
+
+ for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
+ pte_t *pte, entry;
+ entry = pfn_pte(my_zero_pfn(haddr), vma->vm_page_prot);
+ entry = pte_mkspecial(entry);
+ pte = pte_offset_map(&_pmd, haddr);
+ VM_BUG_ON(!pte_none(*pte));
+ set_pte_at(mm, haddr, pte, entry);
+ pte_unmap(pte);
+ }
+ smp_wmb(); /* make pte visible before pmd */
+ pmd_populate(mm, pmd, pgtable);
+ put_huge_zero_page();
+}
+
+void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address,
+ pmd_t *pmd)
+{
+ spinlock_t *ptl;
+ struct page *page;
+ struct mm_struct *mm = vma->vm_mm;
+ unsigned long haddr = address & HPAGE_PMD_MASK;
+ unsigned long mmun_start; /* For mmu_notifiers */
+ unsigned long mmun_end; /* For mmu_notifiers */
+
+ BUG_ON(vma->vm_start > haddr || vma->vm_end < haddr + HPAGE_PMD_SIZE);
+
+ mmun_start = haddr;
+ mmun_end = haddr + HPAGE_PMD_SIZE;
+again:
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ ptl = pmd_lock(mm, pmd);
+ if (unlikely(!pmd_trans_huge(*pmd))) {
+ spin_unlock(ptl);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ return;
+ }
+ if (is_huge_zero_pmd(*pmd)) {
+ __split_huge_zero_page_pmd(vma, haddr, pmd);
+ spin_unlock(ptl);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ return;
+ }
+ page = pmd_page(*pmd);
+ VM_BUG_ON_PAGE(!page_count(page), page);
+ get_page(page);
+ spin_unlock(ptl);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+
+ split_huge_page(page);
+
+ put_page(page);
+
+ /*
+ * We don't always have down_write of mmap_sem here: a racing
+ * do_huge_pmd_wp_page() might have copied-on-write to another
+ * huge page before our split_huge_page() got the anon_vma lock.
+ */
+ if (unlikely(pmd_trans_huge(*pmd)))
+ goto again;
+}
+
+void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
+ pmd_t *pmd)
+{
+ struct vm_area_struct *vma;
+
+ vma = find_vma(mm, address);
+ BUG_ON(vma == NULL);
+ split_huge_page_pmd(vma, address, pmd);
+}
+
+static void split_huge_page_address(struct mm_struct *mm,
+ unsigned long address)
+{
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+
+ VM_BUG_ON(!(address & ~HPAGE_PMD_MASK));
+
+ pgd = pgd_offset(mm, address);
+ if (!pgd_present(*pgd))
+ return;
+
+ pud = pud_offset(pgd, address);
+ if (!pud_present(*pud))
+ return;
+
+ pmd = pmd_offset(pud, address);
+ if (!pmd_present(*pmd))
+ return;
+ /*
+ * Caller holds the mmap_sem write mode, so a huge pmd cannot
+ * materialize from under us.
+ */
+ split_huge_page_pmd_mm(mm, address, pmd);
+}
static int __split_huge_page_splitting(struct page *page,
struct vm_area_struct *vma,
unsigned long address)
@@ -2808,118 +2919,6 @@ static int khugepaged(void *none)
return 0;
}
-static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
- unsigned long haddr, pmd_t *pmd)
-{
- struct mm_struct *mm = vma->vm_mm;
- pgtable_t pgtable;
- pmd_t _pmd;
- int i;
-
- pmdp_clear_flush(vma, haddr, pmd);
- /* leave pmd empty until pte is filled */
-
- pgtable = pgtable_trans_huge_withdraw(mm, pmd);
- pmd_populate(mm, &_pmd, pgtable);
-
- for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
- pte_t *pte, entry;
- entry = pfn_pte(my_zero_pfn(haddr), vma->vm_page_prot);
- entry = pte_mkspecial(entry);
- pte = pte_offset_map(&_pmd, haddr);
- VM_BUG_ON(!pte_none(*pte));
- set_pte_at(mm, haddr, pte, entry);
- pte_unmap(pte);
- }
- smp_wmb(); /* make pte visible before pmd */
- pmd_populate(mm, pmd, pgtable);
- put_huge_zero_page();
-}
-
-void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address,
- pmd_t *pmd)
-{
- spinlock_t *ptl;
- struct page *page;
- struct mm_struct *mm = vma->vm_mm;
- unsigned long haddr = address & HPAGE_PMD_MASK;
- unsigned long mmun_start; /* For mmu_notifiers */
- unsigned long mmun_end; /* For mmu_notifiers */
-
- BUG_ON(vma->vm_start > haddr || vma->vm_end < haddr + HPAGE_PMD_SIZE);
-
- mmun_start = haddr;
- mmun_end = haddr + HPAGE_PMD_SIZE;
-again:
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
- ptl = pmd_lock(mm, pmd);
- if (unlikely(!pmd_trans_huge(*pmd))) {
- spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
- return;
- }
- if (is_huge_zero_pmd(*pmd)) {
- __split_huge_zero_page_pmd(vma, haddr, pmd);
- spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
- return;
- }
- page = pmd_page(*pmd);
- VM_BUG_ON_PAGE(!page_count(page), page);
- get_page(page);
- spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
-
- split_huge_page(page);
-
- put_page(page);
-
- /*
- * We don't always have down_write of mmap_sem here: a racing
- * do_huge_pmd_wp_page() might have copied-on-write to another
- * huge page before our split_huge_page() got the anon_vma lock.
- */
- if (unlikely(pmd_trans_huge(*pmd)))
- goto again;
-}
-
-void split_huge_page_pmd_mm(struct mm_struct *mm, unsigned long address,
- pmd_t *pmd)
-{
- struct vm_area_struct *vma;
-
- vma = find_vma(mm, address);
- BUG_ON(vma == NULL);
- split_huge_page_pmd(vma, address, pmd);
-}
-
-static void split_huge_page_address(struct mm_struct *mm,
- unsigned long address)
-{
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
-
- VM_BUG_ON(!(address & ~HPAGE_PMD_MASK));
-
- pgd = pgd_offset(mm, address);
- if (!pgd_present(*pgd))
- return;
-
- pud = pud_offset(pgd, address);
- if (!pud_present(*pud))
- return;
-
- pmd = pmd_offset(pud, address);
- if (!pmd_present(*pmd))
- return;
- /*
- * Caller holds the mmap_sem write mode, so a huge pmd cannot
- * materialize from under us.
- */
- split_huge_page_pmd_mm(mm, address, pmd);
-}
-
void __vma_adjust_trans_huge(struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
--
2.1.1
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