2022-03-02 13:48:13

by Muchun Song

Subject: [PATCH v4 6/6] mm: remove range parameter from follow_invalidate_pte()

The only user (DAX) of range parameter of follow_invalidate_pte()
is gone, it safe to remove the range paramter and make it static
to simlify the code.

Signed-off-by: Muchun Song <[email protected]>
---
include/linux/mm.h | 3 ---
mm/memory.c | 23 +++--------------------
2 files changed, 3 insertions(+), 23 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index c9bada4096ac..be7ec4c37ebe 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -1871,9 +1871,6 @@ void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
unsigned long end, unsigned long floor, unsigned long ceiling);
int
copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma);
-int follow_invalidate_pte(struct mm_struct *mm, unsigned long address,
- struct mmu_notifier_range *range, pte_t **ptepp,
- pmd_t **pmdpp, spinlock_t **ptlp);
int follow_pte(struct mm_struct *mm, unsigned long address,
pte_t **ptepp, spinlock_t **ptlp);
int follow_pfn(struct vm_area_struct *vma, unsigned long address,
diff --git a/mm/memory.c b/mm/memory.c
index cc6968dc8e4e..278ab6d62b54 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -4964,9 +4964,8 @@ int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
}
#endif /* __PAGETABLE_PMD_FOLDED */

-int follow_invalidate_pte(struct mm_struct *mm, unsigned long address,
- struct mmu_notifier_range *range, pte_t **ptepp,
- pmd_t **pmdpp, spinlock_t **ptlp)
+static int follow_invalidate_pte(struct mm_struct *mm, unsigned long address,
+ pte_t **ptepp, pmd_t **pmdpp, spinlock_t **ptlp)
{
pgd_t *pgd;
p4d_t *p4d;
@@ -4993,31 +4992,17 @@ int follow_invalidate_pte(struct mm_struct *mm, unsigned long address,
if (!pmdpp)
goto out;

- if (range) {
- mmu_notifier_range_init(range, MMU_NOTIFY_CLEAR, 0,
- NULL, mm, address & PMD_MASK,
- (address & PMD_MASK) + PMD_SIZE);
- mmu_notifier_invalidate_range_start(range);
- }
*ptlp = pmd_lock(mm, pmd);
if (pmd_huge(*pmd)) {
*pmdpp = pmd;
return 0;
}
spin_unlock(*ptlp);
- if (range)
- mmu_notifier_invalidate_range_end(range);
}

if (pmd_none(*pmd) || unlikely(pmd_bad(*pmd)))
goto out;

- if (range) {
- mmu_notifier_range_init(range, MMU_NOTIFY_CLEAR, 0, NULL, mm,
- address & PAGE_MASK,
- (address & PAGE_MASK) + PAGE_SIZE);
- mmu_notifier_invalidate_range_start(range);
- }
ptep = pte_offset_map_lock(mm, pmd, address, ptlp);
if (!pte_present(*ptep))
goto unlock;
@@ -5025,8 +5010,6 @@ int follow_invalidate_pte(struct mm_struct *mm, unsigned long address,
return 0;
unlock:
pte_unmap_unlock(ptep, *ptlp);
- if (range)
- mmu_notifier_invalidate_range_end(range);
out:
return -EINVAL;
}
@@ -5055,7 +5038,7 @@ int follow_invalidate_pte(struct mm_struct *mm, unsigned long address,
int follow_pte(struct mm_struct *mm, unsigned long address,
pte_t **ptepp, spinlock_t **ptlp)
{
- return follow_invalidate_pte(mm, address, NULL, ptepp, NULL, ptlp);
+ return follow_invalidate_pte(mm, address, ptepp, NULL, ptlp);
}
EXPORT_SYMBOL_GPL(follow_pte);

--
2.11.0

2022-03-10 03:03:01

by Dan Williams

Subject: Re: [PATCH v4 6/6] mm: remove range parameter from follow_invalidate_pte()

On Wed, Mar 2, 2022 at 12:30 AM Muchun Song <[email protected]> wrote:
>
> The only user (DAX) of range parameter of follow_invalidate_pte()
> is gone, it safe to remove the range paramter and make it static
> to simlify the code.
>

Looks good, I suspect this savings is still valid if the "just use
page_mkclean_one" directly feedback is workable.

Otherwise you can add:

Reviewed-by: Dan Williams <[email protected]>