# HG changeset patch
# User kfraser@xxxxxxxxxxxxxxxxxxxxx
# Node ID affbab70fca28b6ab6bb483bc149543c21aa2617
# Parent 6d83c86ebfe913b23bdd1e59278e0b4f605047dd
[XEN] Move mark_dirty() from alloc_page_type() to get_page_type(),
for symmetry with put_page_type(). Limit calls to mark_dirty() in
put_page_type() so that they happen only for page-table pages.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
xen/arch/x86/mm.c | 38 +++++++++++++++-----------------------
1 files changed, 15 insertions(+), 23 deletions(-)
diff -r 6d83c86ebfe9 -r affbab70fca2 xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c Wed Sep 20 18:33:26 2006 +0100
+++ b/xen/arch/x86/mm.c Wed Sep 20 18:41:44 2006 +0100
@@ -1490,26 +1490,19 @@ static int mod_l4_entry(l4_pgentry_t *pl
int alloc_page_type(struct page_info *page, unsigned long type)
{
- int rc;
-
switch ( type & PGT_type_mask )
{
case PGT_l1_page_table:
- rc = alloc_l1_table(page);
- break;
+ return alloc_l1_table(page);
case PGT_l2_page_table:
- rc = alloc_l2_table(page, type);
- break;
+ return alloc_l2_table(page, type);
case PGT_l3_page_table:
- rc = alloc_l3_table(page);
- break;
+ return alloc_l3_table(page);
case PGT_l4_page_table:
- rc = alloc_l4_table(page);
- break;
+ return alloc_l4_table(page);
case PGT_gdt_page:
case PGT_ldt_page:
- rc = alloc_segdesc_page(page);
- break;
+ return alloc_segdesc_page(page);
default:
printk("Bad type in alloc_page_type %lx t=%" PRtype_info " c=%x\n",
type, page->u.inuse.type_info,
@@ -1517,15 +1510,7 @@ int alloc_page_type(struct page_info *pa
BUG();
}
- /*
- * A page is dirtied when its type count becomes non-zero.
- * It is safe to mark dirty here because any PTE modifications in
- * alloc_l?_table have now happened. The caller has already set the type
- * and incremented the reference count.
- */
- mark_dirty(page_get_owner(page), page_to_mfn(page));
-
- return rc;
+ return 0;
}
@@ -1625,11 +1610,11 @@ void put_page_type(struct page_info *pag
while ( unlikely((y = cmpxchg(&page->u.inuse.type_info, x, nx)) != x) );
/*
- * A page is dirtied when its type count becomes zero.
+ * A page table is dirtied when its type count becomes zero.
* We cannot set the dirty flag earlier than this because we must wait
* until the type count has been zeroed by the CMPXCHG above.
*/
- if ( unlikely((nx & PGT_count_mask) == 0) )
+ if ( unlikely((nx & (PGT_validated|PGT_count_mask)) == 0) )
mark_dirty(page_get_owner(page), page_to_mfn(page));
}
@@ -1716,6 +1701,13 @@ int get_page_type(struct page_info *page
/* Noone else is updating simultaneously. */
__set_bit(_PGT_validated, &page->u.inuse.type_info);
+
+ /*
+ * A page table is dirtied when its type count becomes non-zero. It is
+ * safe to mark dirty here because any PTE modifications in
+ * alloc_page_type() have now happened.
+ */
+ mark_dirty(page_get_owner(page), page_to_mfn(page));
}
return 1;
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