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thp: pte alloc trans splitting

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pte alloc routines must wait for split_huge_page if the pmd is not present
and not null (i.e.  pmd_trans_splitting).  The additional branches are
optimized away at compile time by pmd_trans_splitting if the config option
is off.  However we must pass the vma down in order to know the anon_vma
lock to wait for.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrea Arcangeli
2011-01-13 15:46:43 -08:00
committed by Linus Torvalds
parent 64cc6ae001
commit 8ac1f8320a
11 changed files with 35 additions and 23 deletions
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19
mm/memory.c
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@@ -394,9 +394,11 @@ void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *vma,
}
}
int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address)
int __pte_alloc(struct mm_struct *mm, struct vm_area_struct *vma,
pmd_t *pmd, unsigned long address)
{
pgtable_t new = pte_alloc_one(mm, address);
int wait_split_huge_page;
if (!new)
return -ENOMEM;
@@ -416,14 +418,18 @@ int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address)
smp_wmb(); /* Could be smp_wmb__xxx(before|after)_spin_lock */
spin_lock(&mm->page_table_lock);
if (!pmd_present(*pmd)) { /* Has another populated it ? */
wait_split_huge_page = 0;
if (likely(pmd_none(*pmd))) { /* Has another populated it ? */
mm->nr_ptes++;
pmd_populate(mm, pmd, new);
new = NULL;
}
} else if (unlikely(pmd_trans_splitting(*pmd)))
wait_split_huge_page = 1;
spin_unlock(&mm->page_table_lock);
if (new)
pte_free(mm, new);
if (wait_split_huge_page)
wait_split_huge_page(vma->anon_vma, pmd);
return 0;
}
@@ -436,10 +442,11 @@ int __pte_alloc_kernel(pmd_t *pmd, unsigned long address)
smp_wmb(); /* See comment in __pte_alloc */
spin_lock(&init_mm.page_table_lock);
if (!pmd_present(*pmd)) { /* Has another populated it ? */
if (likely(pmd_none(*pmd))) { /* Has another populated it ? */
pmd_populate_kernel(&init_mm, pmd, new);
new = NULL;
}
} else
VM_BUG_ON(pmd_trans_splitting(*pmd));
spin_unlock(&init_mm.page_table_lock);
if (new)
pte_free_kernel(&init_mm, new);
@@ -3253,7 +3260,7 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
pmd = pmd_alloc(mm, pud, address);
if (!pmd)
return VM_FAULT_OOM;
pte = pte_alloc_map(mm, pmd, address);
pte = pte_alloc_map(mm, vma, pmd, address);
if (!pte)
return VM_FAULT_OOM;