3 files changed, 35 insertions, 5 deletions

diff --git a/tools/xenpaging/policy.h b/tools/xenpaging/policy.h
index 18a92569ca..458ed27ce5 100644
--- a/tools/xenpaging/policy.h
+++ b/tools/xenpaging/policy.h
@@ -32,6 +32,8 @@ int policy_init(xenpaging_t *paging);
 int policy_choose_victim(xenpaging_t *paging, xenpaging_victim_t *victim);
 void policy_notify_paged_out(unsigned long gfn);
 void policy_notify_paged_in(unsigned long gfn);
+void policy_notify_paged_in_nomru(unsigned long gfn);
+void policy_notify_dropped(unsigned long gfn);
 
 #endif // __XEN_PAGING_POLICY_H__
 
diff --git a/tools/xenpaging/policy_default.c b/tools/xenpaging/policy_default.c
index 0285d0dd8a..e555ed4e59 100644
--- a/tools/xenpaging/policy_default.c
+++ b/tools/xenpaging/policy_default.c
@@ -57,7 +57,7 @@ int policy_init(xenpaging_t *paging)
     if ( paging->policy_mru_size > 0 )
         mru_size = paging->policy_mru_size;
     else
-        mru_size = DEFAULT_MRU_SIZE;
+        mru_size = paging->policy_mru_size = DEFAULT_MRU_SIZE;
 
     mru = malloc(sizeof(*mru) * mru_size);
     if ( mru == NULL )
@@ -120,17 +120,38 @@ void policy_notify_paged_out(unsigned long gfn)
     clear_bit(gfn, unconsumed);
 }
 
-void policy_notify_paged_in(unsigned long gfn)
+static void policy_handle_paged_in(unsigned long gfn, int do_mru)
 {
     unsigned long old_gfn = mru[i_mru & (mru_size - 1)];
 
     if ( old_gfn != INVALID_MFN )
         clear_bit(old_gfn, bitmap);
     
-    mru[i_mru & (mru_size - 1)] = gfn;
+    if (do_mru) {
+        mru[i_mru & (mru_size - 1)] = gfn;
+    } else {
+        clear_bit(gfn, bitmap);
+        mru[i_mru & (mru_size - 1)] = INVALID_MFN;
+    }
+
     i_mru++;
 }
 
+void policy_notify_paged_in(unsigned long gfn)
+{
+    policy_handle_paged_in(gfn, 1);
+}
+
+void policy_notify_paged_in_nomru(unsigned long gfn)
+{
+    policy_handle_paged_in(gfn, 0);
+}
+
+void policy_notify_dropped(unsigned long gfn)
+{
+    clear_bit(gfn, bitmap);
+}
+
 
 /*
  * Local variables:
diff --git a/tools/xenpaging/xenpaging.c b/tools/xenpaging/xenpaging.c
index f6cd05f700..8f9f52d1e0 100644
--- a/tools/xenpaging/xenpaging.c
+++ b/tools/xenpaging/xenpaging.c
@@ -615,7 +615,14 @@ static int xenpaging_resume_page(xenpaging_t *paging, mem_event_response_t *rsp,
     /* Notify policy of page being paged in */
     if ( notify_policy )
     {
-        policy_notify_paged_in(rsp->gfn);
+        /*
+         * Do not add gfn to mru list if the target is lower than mru size.
+         * This allows page-out of these gfns if the target grows again.
+         */
+        if (paging->num_paged_out > paging->policy_mru_size)
+            policy_notify_paged_in(rsp->gfn);
+        else
+            policy_notify_paged_in_nomru(rsp->gfn);
 
        /* Record number of resumed pages */
        paging->num_paged_out--;
@@ -869,7 +876,7 @@ int main(int argc, char *argv[])
                 {
                     DPRINTF("drop_page ^ gfn %"PRIx64" pageslot %d\n", req.gfn, i);
                     /* Notify policy of page being dropped */
-                    policy_notify_paged_in(req.gfn);
+                    policy_notify_dropped(req.gfn);
                 }
                 else
                 {