Subject: [PATCH 1/9] mm/huge_memory: Use zap_deposited_table() more

From: Oliver O'Halloran <[email-masked]>
Date: Wed, 12 Apr 2017 03:42:25 +1000

Depending flags of the PMD being zapped there may or may not be a
deposited pgtable to be freed. In two of the three cases this is open
coded while the third uses the zap_deposited_table() helper. This patch
converts the others to use the helper to clean things up a bit.

Cc: "Aneesh Kumar K.V" <[email-masked]>
Cc: "Kirill A. Shutemov" <[email-masked]>
Cc: [email-masked]
Signed-off-by: Oliver O'Halloran <[email-masked]>
---
For reference:

void zap_deposited_table(struct mm_struct *mm, pmd_t *pmd)
{
        pgtable_t pgtable;

        pgtable = pgtable_trans_huge_withdraw(mm, pmd);
        pte_free(mm, pgtable);
        atomic_long_dec(&mm->nr_ptes);
}
---
 mm/huge_memory.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b787c4cfda0e..aa01dd47cc65 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1615,8 +1615,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		if (is_huge_zero_pmd(orig_pmd))
 			tlb_remove_page_size(tlb, pmd_page(orig_pmd), HPAGE_PMD_SIZE);
 	} 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);
+		zap_deposited_table(tlb->mm, pmd);
 		spin_unlock(ptl);
 		tlb_remove_page_size(tlb, pmd_page(orig_pmd), HPAGE_PMD_SIZE);
 	} else {
@@ -1625,10 +1624,7 @@ int zap_huge_pmd(struct mmu_gather *tlb, struct vm_area_struct *vma,
 		VM_BUG_ON_PAGE(page_mapcount(page) < 0, page);
 		VM_BUG_ON_PAGE(!PageHead(page), page);
 		if (PageAnon(page)) {
-			pgtable_t pgtable;
-			pgtable = pgtable_trans_huge_withdraw(tlb->mm, pmd);
-			pte_free(tlb->mm, pgtable);
-			atomic_long_dec(&tlb->mm->nr_ptes);
+			zap_deposited_table(tlb->mm, pmd);
 			add_mm_counter(tlb->mm, MM_ANONPAGES, -HPAGE_PMD_NR);
 		} else {
 			if (arch_needs_pgtable_deposit())
-- 
2.9.3