The patch titled
Subject: mm: migrate: one less atomic operation
has been added to the -mm tree. Its filename is
mm-migrate-one-less-atomic-operation.patch
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------------------------------------------------------
From: Jacobo Giralt <jacobo.giralt@xxxxxxxxx>
Subject: mm: migrate: one less atomic operation
migrate_page_move_mapping() drops a reference from the old page after
unfreezing its counter. Both operations can be merged into a single
atomic operation by directly unfreezing to one less reference.
The same applies to migrate_huge_page_move_mapping().
Signed-off-by: Jacobo Giralt <jacobo.giralt@xxxxxxxxx>
Cc: Mel Gorman <mel@xxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
Cc: Johannes Weiner <jweiner@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/migrate.c | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff -puN mm/migrate.c~mm-migrate-one-less-atomic-operation mm/migrate.c
--- a/mm/migrate.c~mm-migrate-one-less-atomic-operation
+++ a/mm/migrate.c
@@ -269,12 +269,12 @@ static int migrate_page_move_mapping(str
radix_tree_replace_slot(pslot, newpage);
- page_unfreeze_refs(page, expected_count);
/*
- * Drop cache reference from old page.
+ * Drop cache reference from old page by unfreezing
+ * to one less reference.
* We know this isn't the last reference.
*/
- __put_page(page);
+ page_unfreeze_refs(page, expected_count - 1);
/*
* If moved to a different zone then also account
@@ -334,9 +334,7 @@ int migrate_huge_page_move_mapping(struc
radix_tree_replace_slot(pslot, newpage);
- page_unfreeze_refs(page, expected_count);
-
- __put_page(page);
+ page_unfreeze_refs(page, expected_count - 1);
spin_unlock_irq(&mapping->tree_lock);
return 0;
_
Subject: Subject: mm: migrate: one less atomic operation
Patches currently in -mm which might be from jacobo.giralt@xxxxxxxxx are
mm-migrate-one-less-atomic-operation.patch
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