The patch titled
page migration cleanup: drop nr_refs in remove_references()
has been added to the -mm tree. Its filename is
page-migration-cleanup-drop-nr_refs-in-remove_references.patch
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
From: Christoph Lameter <clameter@xxxxxxx>
Drop nr_refs parameter from migrate_page_remove_references()
The nr_refs parameter is not really useful since the number of remaining
references is always
1 for anonymous pages without a mapping
2 for pages with a mapping
3 for pages with a mapping and PagePrivate set.
Remove the early check for the number of references since we are checking
page_mapcount() earlier. Ultimately only the refcount matters after the
tree_lock has been obtained.
Signed-off-by: Christoph Lameter <clameter@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/migrate.c | 21 +++++++++++----------
1 files changed, 11 insertions(+), 10 deletions(-)
diff -puN mm/migrate.c~page-migration-cleanup-drop-nr_refs-in-remove_references mm/migrate.c
--- devel/mm/migrate.c~page-migration-cleanup-drop-nr_refs-in-remove_references 2006-04-29 00:20:43.000000000 -0700
+++ devel-akpm/mm/migrate.c 2006-04-29 00:20:43.000000000 -0700
@@ -168,19 +168,19 @@ retry:
/*
* Remove references for a page and establish the new page with the correct
* basic settings to be able to stop accesses to the page.
+ *
+ * The number of remaining references must be:
+ * 1 for anonymous pages without a mapping
+ * 2 for pages with a mapping
+ * 3 for pages with a mapping and PagePrivate set.
*/
static int migrate_page_remove_references(struct page *newpage,
- struct page *page, int nr_refs)
+ struct page *page)
{
struct address_space *mapping = page_mapping(page);
struct page **radix_pointer;
- /*
- * Avoid doing any of the following work if the page count
- * indicates that the page is in use or truncate has removed
- * the page.
- */
- if (!mapping || page_mapcount(page) + nr_refs != page_count(page))
+ if (!mapping)
return -EAGAIN;
/*
@@ -218,7 +218,8 @@ static int migrate_page_remove_reference
&mapping->page_tree,
page_index(page));
- if (!page_mapping(page) || page_count(page) != nr_refs ||
+ if (!page_mapping(page) ||
+ page_count(page) != 2 + !!PagePrivate(page) ||
*radix_pointer != page) {
write_unlock_irq(&mapping->tree_lock);
return -EAGAIN;
@@ -309,7 +310,7 @@ int migrate_page(struct page *newpage, s
BUG_ON(PageWriteback(page)); /* Writeback must be complete */
- rc = migrate_page_remove_references(newpage, page, 2);
+ rc = migrate_page_remove_references(newpage, page);
if (rc)
return rc;
@@ -348,7 +349,7 @@ int buffer_migrate_page(struct page *new
head = page_buffers(page);
- rc = migrate_page_remove_references(newpage, page, 3);
+ rc = migrate_page_remove_references(newpage, page);
if (rc)
return rc;
_
Patches currently in -mm which might be from clameter@xxxxxxx are
origin.patch
page-migration-fix-fallback-behavior-for-dirty-pages.patch
page-migration-make-do_swap_page-redo-the-fault.patch
slab-extract-cache_free_alien-from-__cache_free.patch
migration-remove-unnecessary-pageswapcache-checks.patch
page-migration-cleanup-rename-ignrefs-to-migration.patch
page-migration-cleanup-group-functions.patch
page-migration-cleanup-remove-useless-definitions.patch
page-migration-cleanup-drop-nr_refs-in-remove_references.patch
page-migration-cleanup-extract-try_to_unmap-from-migration-functions.patch
page-migration-cleanup-pass-mapping-to-migration-functions.patch
page-migration-cleanup-move-fallback-handling-into-special-function.patch
swapless-pm-add-r-w-migration-entries.patch
swapless-page-migration-rip-out-swap-based-logic.patch
swapless-page-migration-modify-core-logic.patch
more-page-migration-do-not-inc-dec-rss-counters.patch
more-page-migration-use-migration-entries-for-file-pages.patch
-
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