From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
The original DAX code assumed that pgtable_t was a pointer, which isn't
true on all architectures. Restructure the code to not rely on that
assumption.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
[further fixes from Matthew integrated into this patch]
Signed-off-by: Matthew Wilcox <willy@xxxxxxxxxxxxxxx>
---
mm/huge_memory.c | 71 +++++++++++++++++++++++++-------------------------------
1 file changed, 31 insertions(+), 40 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 326d17e..b51bed1 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1426,50 +1426,41 @@ out:
int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
pmd_t *pmd, unsigned long addr)
{
+ pmd_t orig_pmd;
spinlock_t *ptl;
- int ret = 0;
- if (__pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
- pgtable_t pgtable;
- pmd_t orig_pmd;
- /*
- * For architectures like ppc64 we look at deposited pgtable
- * when calling pmdp_huge_get_and_clear. So do the
- * pgtable_trans_huge_withdraw after finishing pmdp related
- * operations.
- */
- orig_pmd = pmdp_huge_get_and_clear_full(tlb->mm, addr, pmd,
- tlb->fullmm);
- tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
- if (vma_is_dax(vma)) {
- if (is_huge_zero_pmd(orig_pmd)) {
- pgtable = NULL;
- } else {
- spin_unlock(ptl);
- return 1;
- }
- } else {
- pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd);
- }
- if (is_huge_zero_pmd(orig_pmd)) {
- atomic_long_dec(&tlb->mm->nr_ptes);
- spin_unlock(ptl);
+ if (__pmd_trans_huge_lock(pmd, vma, &ptl) != 1)
+ return 0;
+ /*
+ * For architectures like ppc64 we look at deposited pgtable
+ * when calling pmdp_huge_get_and_clear. So do the
+ * pgtable_trans_huge_withdraw after finishing pmdp related
+ * operations.
+ */
+ orig_pmd = pmdp_huge_get_and_clear_full(tlb->mm, addr, pmd,
+ tlb->fullmm);
+ tlb_remove_pmd_tlb_entry(tlb, pmd, addr);
+ if (vma_is_dax(vma)) {
+ spin_unlock(ptl);
+ if (is_huge_zero_pmd(orig_pmd))
put_huge_zero_page();
- } else {
- struct page *page = pmd_page(orig_pmd);
- page_remove_rmap(page);
- VM_BUG_ON_PAGE(page_mapcount(page) < 0, page);
- add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
- VM_BUG_ON_PAGE(!PageHead(page), page);
- atomic_long_dec(&tlb->mm->nr_ptes);
- spin_unlock(ptl);
- tlb_remove_page(tlb, page);
- }
- if (pgtable)
- pte_free(tlb->mm, pgtable);
- ret = 1;
+ } else if (is_huge_zero_pmd(orig_pmd)) {
+ pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd));
+ atomic_long_dec(&tlb->mm->nr_ptes);
+ spin_unlock(ptl);
+ put_huge_zero_page();
+ } else {
+ struct page *page = pmd_page(orig_pmd);
+ page_remove_rmap(page);
+ VM_BUG_ON_PAGE(page_mapcount(page) < 0, page);
+ add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
+ VM_BUG_ON_PAGE(!PageHead(page), page);
+ pte_free(tlb->mm, pgtable_trans_huge_withdraw(tlb->mm, pmd));
+ atomic_long_dec(&tlb->mm->nr_ptes);
+ spin_unlock(ptl);
+ tlb_remove_page(tlb, page);
}
- return ret;
+ return 1;
}
int move_huge_pmd(struct vm_area_struct *vma, struct vm_area_struct *new_vma,
--
2.1.4
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