[PATCH 31/39] autonuma: make khugepaged pte_numa aware

From: Andrea Arcangeli
Date: Mon Mar 26 2012 - 15:09:17 EST


If any of the ptes that khugepaged is collapsing was a pte_numa, the
resulting trans huge pmd will be a pmd_numa too.

Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
---
mm/huge_memory.c | 13 +++++++++++--
1 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index b1c047b..d388517 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1790,12 +1790,13 @@ out:
return isolated;
}

-static void __collapse_huge_page_copy(pte_t *pte, struct page *page,
+static bool __collapse_huge_page_copy(pte_t *pte, struct page *page,
struct vm_area_struct *vma,
unsigned long address,
spinlock_t *ptl)
{
pte_t *_pte;
+ bool mknuma = false;
for (_pte = pte; _pte < pte+HPAGE_PMD_NR; _pte++) {
pte_t pteval = *_pte;
struct page *src_page;
@@ -1823,11 +1824,15 @@ static void __collapse_huge_page_copy(pte_t *pte, struct page *page,
page_remove_rmap(src_page);
spin_unlock(ptl);
free_page_and_swap_cache(src_page);
+
+ mknuma |= pte_numa(pteval);
}

address += PAGE_SIZE;
page++;
}
+
+ return mknuma;
}

static void collapse_huge_page(struct mm_struct *mm,
@@ -1845,6 +1850,7 @@ static void collapse_huge_page(struct mm_struct *mm,
spinlock_t *ptl;
int isolated;
unsigned long hstart, hend;
+ bool mknuma = false;

VM_BUG_ON(address & ~HPAGE_PMD_MASK);
#ifndef CONFIG_NUMA
@@ -1963,7 +1969,8 @@ static void collapse_huge_page(struct mm_struct *mm,
*/
anon_vma_unlock(vma->anon_vma);

- __collapse_huge_page_copy(pte, new_page, vma, address, ptl);
+ mknuma = pmd_numa(_pmd);
+ mknuma |= __collapse_huge_page_copy(pte, new_page, vma, address, ptl);
pte_unmap(pte);
__SetPageUptodate(new_page);
pgtable = pmd_pgtable(_pmd);
@@ -1973,6 +1980,8 @@ static void collapse_huge_page(struct mm_struct *mm,
_pmd = mk_pmd(new_page, vma->vm_page_prot);
_pmd = maybe_pmd_mkwrite(pmd_mkdirty(_pmd), vma);
_pmd = pmd_mkhuge(_pmd);
+ if (mknuma)
+ _pmd = pmd_mknuma(_pmd);

/*
* spin_lock() below is not the equivalent of smp_wmb(), so
--
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