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mm: cleanup *pte_alloc* interfaces

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There are few things about *pte_alloc*() helpers worth cleaning up:

 - 'vma' argument is unused, let's drop it;

 - most __pte_alloc() callers do speculative check for pmd_none(),
   before taking ptl: let's introduce pte_alloc() macro which does
   the check.

   The only direct user of __pte_alloc left is userfaultfd, which has
   different expectation about atomicity wrt pmd.

 - pte_alloc_map() and pte_alloc_map_lock() are redefined using
   pte_alloc().

[sudeep.holla@arm.com: fix build for arm64 hugetlbpage]
[sfr@canb.auug.org.au: fix arch/arm/mm/mmu.c some more]
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Kirill A. Shutemov
2016-03-17 14:19:11 -07:00
committed by Linus Torvalds
parent 5057dcd0f1
commit 3ed3a4f0dd
16 changed files with 27 additions and 32 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
mm/memory.c
View File

@@ -562,8 +562,7 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma,
}
}
int __pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
pmd_t *pmd, unsigned long address)
int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address)
{
spinlock_t *ptl;
pgtable_t new = pte_alloc_one(mm, address);
@@ -3419,12 +3418,11 @@ static int __handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
}
/*
* Use __pte_alloc instead of pte_alloc_map, because we can't
* Use pte_alloc() instead of pte_alloc_map, because we can't
* run pte_offset_map on the pmd, if an huge pmd could
* materialize from under us from a different thread.
*/
if (unlikely(pmd_none(*pmd)) &&
unlikely(__pte_alloc(mm, vma, pmd, address)))
if (unlikely(pte_alloc(mm, pmd, address)))
return VM_FAULT_OOM;
/*
* If a huge pmd materialized under us just retry later. Use

3
mm/mremap.c
View File

@@ -213,8 +213,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
continue;
VM_BUG_ON(pmd_trans_huge(*old_pmd));
}
if (pmd_none(*new_pmd) && __pte_alloc(new_vma->vm_mm, new_vma,
new_pmd, new_addr))
if (pte_alloc(new_vma->vm_mm, new_pmd, new_addr))
break;
next = (new_addr + PMD_SIZE) & PMD_MASK;
if (extent > next - new_addr)

3
mm/userfaultfd.c
View File

@@ -230,8 +230,7 @@ retry:
break;
}
if (unlikely(pmd_none(dst_pmdval)) &&
unlikely(__pte_alloc(dst_mm, dst_vma, dst_pmd,
dst_addr))) {
unlikely(__pte_alloc(dst_mm, dst_pmd, dst_addr))) {
err = -ENOMEM;
break;
}