The patch titled
page migration cleanup: move fallback handling into special function
has been added to the -mm tree. Its filename is
page-migration-cleanup-move-fallback-handling-into-special-function.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>
Move the fallback code into a new fallback function and make the function
behave like any other migration function. This requires retaking the lock if
pageout() drops it.
Signed-off-by: Christoph Lameter <clameter@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxx>
---
mm/migrate.c | 90 +++++++++++++++++++++----------------------------
1 files changed, 39 insertions(+), 51 deletions(-)
diff -puN mm/migrate.c~page-migration-cleanup-move-fallback-handling-into-special-function mm/migrate.c
--- devel/mm/migrate.c~page-migration-cleanup-move-fallback-handling-into-special-function 2006-04-29 00:20:50.000000000 -0700
+++ devel-akpm/mm/migrate.c 2006-04-29 00:20:50.000000000 -0700
@@ -349,6 +349,42 @@ int buffer_migrate_page(struct address_s
}
EXPORT_SYMBOL(buffer_migrate_page);
+static int fallback_migrate_page(struct address_space *mapping,
+ struct page *newpage, struct page *page)
+{
+ /*
+ * Default handling if a filesystem does not provide
+ * a migration function. We can only migrate clean
+ * pages so try to write out any dirty pages first.
+ */
+ if (PageDirty(page)) {
+ switch (pageout(page, mapping)) {
+ case PAGE_KEEP:
+ case PAGE_ACTIVATE:
+ return -EAGAIN;
+
+ case PAGE_SUCCESS:
+ /* Relock since we lost the lock */
+ lock_page(page);
+ /* Must retry since page state may have changed */
+ return -EAGAIN;
+
+ case PAGE_CLEAN:
+ ; /* try to migrate the page below */
+ }
+ }
+
+ /*
+ * Buffers are managed in a filesystem specific way.
+ * We must have no buffers or drop them.
+ */
+ if (page_has_buffers(page) &&
+ !try_to_release_page(page, GFP_KERNEL))
+ return -EAGAIN;
+
+ return migrate_page(mapping, newpage, page);
+}
+
/*
* migrate_pages
*
@@ -478,7 +514,7 @@ redo:
if (!mapping)
goto unlock_both;
- if (mapping->a_ops->migratepage) {
+ if (mapping->a_ops->migratepage)
/*
* Most pages have a mapping and most filesystems
* should provide a migration function. Anonymous
@@ -488,56 +524,8 @@ redo:
*/
rc = mapping->a_ops->migratepage(mapping,
newpage, page);
- goto unlock_both;
- }
-
- /*
- * Default handling if a filesystem does not provide
- * a migration function. We can only migrate clean
- * pages so try to write out any dirty pages first.
- */
- if (PageDirty(page)) {
- switch (pageout(page, mapping)) {
- case PAGE_KEEP:
- case PAGE_ACTIVATE:
- goto unlock_both;
-
- case PAGE_SUCCESS:
- unlock_page(newpage);
- goto next;
-
- case PAGE_CLEAN:
- ; /* try to migrate the page below */
- }
- }
-
- /*
- * Buffers are managed in a filesystem specific way.
- * We must have no buffers or drop them.
- */
- if (!page_has_buffers(page) ||
- try_to_release_page(page, GFP_KERNEL)) {
- rc = migrate_page(mapping, newpage, page);
- goto unlock_both;
- }
-
- /*
- * On early passes with mapped pages simply
- * retry. There may be a lock held for some
- * buffers that may go away. Later
- * swap them out.
- */
- if (pass > 4) {
- /*
- * Persistently unable to drop buffers..... As a
- * measure of last resort we fall back to
- * swap_page().
- */
- unlock_page(newpage);
- newpage = NULL;
- rc = swap_page(page);
- goto next;
- }
+ else
+ rc = fallback_migrate_page(mapping, newpage, page);
unlock_both:
unlock_page(newpage);
_
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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