[PATCH] Swapless page migration: modify core logic

Use the migration entries for page migration

This modifies the migration code to use the new migration entries.  It now
becomes possible to migrate anonymous pages without having to add a swap
entry.

We add a couple of new functions to replace migration entries with the proper
ptes.

We cannot take the tree_lock for migrating anonymous pages anymore.  However,
we know that we hold the only remaining reference to the page when the page
count reaches 1.

Signed-off-by: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/mm/Kconfig b/mm/Kconfig
index 332f5c29b53a..66e65ab39426 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -138,8 +138,8 @@ config SPLIT_PTLOCK_CPUS
 #
 config MIGRATION
         bool "Page migration"
-        def_bool y if NUMA
-        depends on SWAP && NUMA
+        def_bool y
+        depends on NUMA
         help
           Allows the migration of the physical location of pages of processes
           while the virtual addresses are not changed. This is useful for