[PATCH v2 2.6.38-rc8-tip 1/20] 1: mm: Move replace_page() to mm/memory.c

Srikar Dronamraju
2011-03-14T13:39:58Z

User bkpt will use background page replacement approach to insert/delete
breakpoints. Background page replacement approach is based on
replace_page. Hence replace_page() loses its static attribute.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
---
include/linux/mm.h | 2 ++
mm/ksm.c | 62 ----------------------------------------------------
mm/memory.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 64 insertions(+), 62 deletions(-)

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 679300c..01a0740 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -984,6 +984,8 @@ void account_page_writeback(struct page *page);
int set_page_dirty(struct page *page);
int set_page_dirty_lock(struct page *page);
int clear_page_dirty_for_io(struct page *page);
+int replace_page(struct vm_area_struct *vma, struct page *page,
+ struct page *kpage, pte_t orig_pte);

/* Is the vma a continuation of the stack vma above it? */
static inline int vma_stack_continue(struct vm_area_struct *vma, unsigned long addr)
diff --git a/mm/ksm.c b/mm/ksm.c
index c2b2a94..f46e20d 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -765,68 +765,6 @@ out:
return err;
}

-/**
- * replace_page - replace page in vma by new ksm page
- * @vma: vma that holds the pte pointing to page
- * @page: the page we are replacing by kpage
- * @kpage: the ksm page we replace page by
- * @orig_pte: the original value of the pte
- *
- * Returns 0 on success, -EFAULT on failure.
- */
-static int replace_page(struct vm_area_struct *vma, struct page *page,
- struct page *kpage, pte_t orig_pte)
-{
- struct mm_struct *mm = vma->vm_mm;
- pgd_t *pgd;
- pud_t *pud;
- pmd_t *pmd;
- pte_t *ptep;
- spinlock_t *ptl;
- unsigned long addr;
- int err = -EFAULT;
-
- addr = page_address_in_vma(page, vma);
- if (addr == -EFAULT)
- goto out;
-
- pgd = pgd_offset(mm, addr);
- if (!pgd_present(*pgd))
- goto out;
-
- pud = pud_offset(pgd, addr);
- if (!pud_present(*pud))
- goto out;
-
- pmd = pmd_offset(pud, addr);
- BUG_ON(pmd_trans_huge(*pmd));
- if (!pmd_present(*pmd))
- goto out;
-
- ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
- if (!pte_same(*ptep, orig_pte)) {
- pte_unmap_unlock(ptep, ptl);
- goto out;
- }
-
- get_page(kpage);
- page_add_anon_rmap(kpage, vma, addr);
-
- flush_cache_page(vma, addr, pte_pfn(*ptep));
- ptep_clear_flush(vma, addr, ptep);
- set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot));
-
- page_remove_rmap(page);
- if (!page_mapped(page))
- try_to_free_swap(page);
- put_page(page);
-
- pte_unmap_unlock(ptep, ptl);
- err = 0;
-out:
- return err;
-}
-
static int page_trans_compound_anon_split(struct page *page)
{
int ret = 0;
diff --git a/mm/memory.c b/mm/memory.c
index 5823698..2a3021c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2669,6 +2669,68 @@ void unmap_mapping_range(struct address_space *mapping,
}
EXPORT_SYMBOL(unmap_mapping_range);

+/**
+ * replace_page - replace page in vma by new ksm page
+ * @vma: vma that holds the pte pointing to page
+ * @page: the page we are replacing by kpage
+ * @kpage: the ksm page we replace page by
+ * @orig_pte: the original value of the pte
+ *
+ * Returns 0 on success, -EFAULT on failure.
+ */
+int replace_page(struct vm_area_struct *vma, struct page *page,
+ struct page *kpage, pte_t orig_pte)
+{
+ struct mm_struct *mm = vma->vm_mm;
+ pgd_t *pgd;
+ pud_t *pud;
+ pmd_t *pmd;
+ pte_t *ptep;
+ spinlock_t *ptl;
+ unsigned long addr;
+ int err = -EFAULT;
+
+ addr = page_address_in_vma(page, vma);
+ if (addr == -EFAULT)
+ goto out;
+
+ pgd = pgd_offset(mm, addr);
+ if (!pgd_present(*pgd))
+ goto out;
+
+ pud = pud_offset(pgd, addr);
+ if (!pud_present(*pud))
+ goto out;
+
+ pmd = pmd_offset(pud, addr);
+ BUG_ON(pmd_trans_huge(*pmd));
+ if (!pmd_present(*pmd))
+ goto out;
+
+ ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
+ if (!pte_same(*ptep, orig_pte)) {
+ pte_unmap_unlock(ptep, ptl);
+ goto out;
+ }
+
+ get_page(kpage);
+ page_add_anon_rmap(kpage, vma, addr);
+
+ flush_cache_page(vma, addr, pte_pfn(*ptep));
+ ptep_clear_flush(vma, addr, ptep);
+ set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot));
+
+ page_remove_rmap(page);
+ if (!page_mapped(page))
+ try_to_free_swap(page);
+ put_page(page);
+
+ pte_unmap_unlock(ptep, ptl);
+ err = 0;
+out:
+ return err;
+}
+
int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end)
{
struct address_space *mapping = inode->i_mapping;