[PATCH] zone_reclaim: do not unmap file backed pages

zone_reclaim should leave that to the real swapper.  We are only interested
in evicting unmapped pages.

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, 6 insertions, 0 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 61ca0097c834..8277f93148b5 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -477,6 +477,12 @@ static int shrink_list(struct list_head *page_list, struct scan_control *sc)
                  * processes. Try to unmap it here.
                  */
                 if (page_mapped(page) && mapping) {
+                        /*
+                         * No unmapping if we do not swap
+                         */
+                        if (!sc->may_swap)
+                                goto keep_locked;
+
                         switch (try_to_unmap(page)) {
                         case SWAP_FAIL:
                                 goto activate_locked;