migration_entry_wait() doesn't work for hugepage, because page->ptl
on hugepage is unused for now. So this patch introduces a hugepage
variant of this function.
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
---
include/linux/swapops.h | 8 ++++++++
mm/hugetlb.c | 3 ++-
mm/migrate.c | 33 +++++++++++++++++++++++++++++++++
3 files changed, 43 insertions(+), 1 deletions(-)
diff --git v2.6.38-rc1/include/linux/swapops.h v2.6.38-rc1/include/linux/swapops.h
index cd42e30..a220ef5 100644
--- v2.6.38-rc1/include/linux/swapops.h
+++ v2.6.38-rc1/include/linux/swapops.h
@@ -169,3 +169,11 @@ static inline int non_swap_entry(swp_entry_t entry)
return 0;
}
#endif
+
+#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_MIGRATION)
+extern void migration_hugepage_entry_wait(struct mm_struct *mm, pmd_t *pmd,
+ unsigned long address);
+#else
+static inline void migration_hugepage_entry_wait(struct mm_struct *mm,
+ pmd_t *pmd, unsigned long address) { }
+#endif
diff --git v2.6.38-rc1/mm/hugetlb.c v2.6.38-rc1/mm/hugetlb.c
index 97c7471..d3b856a 100644
--- v2.6.38-rc1/mm/hugetlb.c
+++ v2.6.38-rc1/mm/hugetlb.c
@@ -2618,7 +2618,8 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
if (ptep) {
entry = huge_ptep_get(ptep);
if (unlikely(is_hugetlb_entry_migration(entry))) {
- migration_entry_wait(mm, (pmd_t *)ptep, address);
+ migration_hugepage_entry_wait(mm, (pmd_t *)ptep,
+ address);
return 0;
} else if (unlikely(is_hugetlb_entry_hwpoisoned(entry)))
return VM_FAULT_HWPOISON_LARGE |
diff --git v2.6.38-rc1/mm/migrate.c v2.6.38-rc1/mm/migrate.c
index 46fe8cc..363685f 100644
--- v2.6.38-rc1/mm/migrate.c
+++ v2.6.38-rc1/mm/migrate.c
@@ -220,6 +220,39 @@ out:
pte_unmap_unlock(ptep, ptl);
}
+void migration_hugepage_entry_wait(struct mm_struct *mm, pmd_t *pmd,
+ unsigned long address)
+{
+ pte_t *ptep, pte;
+ spinlock_t *ptl;
+ swp_entry_t entry;
+ struct page *page;
+
+ ptep = (pte_t *)pmd;
+ ptl = &(mm)->page_table_lock;
+ spin_lock(ptl);
+ pte = *ptep;
+ if (!is_swap_pte(pte))
+ goto out;
+
+ entry = pte_to_swp_entry(pte);
+ if (!is_migration_entry(entry))
+ goto out;
+
+ page = migration_entry_to_page(entry);
+
+ if (!get_page_unless_zero(page))
+ goto out;
+ spin_unlock(ptl);
+ pte_unmap(ptep);
+ wait_on_page_locked(page);
+ put_page(page);
+ return;
+out:
+ spin_unlock(ptl);
+ pte_unmap(ptep);
+}
+
/*
* Replace the page in the mapping.
*
--
1.7.3.4
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