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

[David Rientjes]

On Wed, 12 Apr 2017, Oliver O'Halloran wrote:

> 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" 
> Cc: "Kirill A. Shutemov" 
> Cc: linux...@kvack.org
> Signed-off-by: Oliver O'Halloran 

Acked-by: David Rientjes 

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

[Aneesh Kumar K.V]

Oliver O'Halloran  writes:

> 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" 
> Cc: "Kirill A. Shutemov" 
> Cc: linux...@kvack.org
> Signed-off-by: Oliver O'Halloran 

Reviewed-by: Aneesh Kumar K.V 

> ---
> 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(>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(>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(>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

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

[Oliver O'Halloran]

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" 
Cc: "Kirill A. Shutemov" 
Cc: linux...@kvack.org
Signed-off-by: Oliver O'Halloran 
---
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(>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(>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(>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