commit 2152f5ca782e51a4d05a1f7d9bfa83286323cbc9
author Juan Quintela <quintela@redhat.com> Tue Oct 08 13:52:02 2013 +0200
committer Juan Quintela <quintela@redhat.com> Mon Jan 13 14:04:54 2014 +0100
tree 7b55bc1cebe4b8703865020081b1e6582d896209
parent 7a5b558c9d061814f34d9b95d70d17ef75037937

memory: only resize dirty bitmap when memory size increases

Signed-off-by: Juan Quintela <quintela@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Orit Wasserman <owasserm@redhat.com>

exec.c

diff --git a/exec.c b/exec.c
index 82aca4a..db369dc 100644
--- a/exec.c
+++ b/exec.c
@@ -1211,6 +1211,9 @@
                                    MemoryRegion *mr)
 {
     RAMBlock *block, *new_block;
+    ram_addr_t old_ram_size, new_ram_size;
+
+    old_ram_size = last_ram_offset() >> TARGET_PAGE_BITS;
 
     size = TARGET_PAGE_ALIGN(size);
     new_block = g_malloc0(sizeof(*new_block));
@@ -1271,10 +1274,13 @@
     ram_list.version++;
     qemu_mutex_unlock_ramlist();
 
-    ram_list.phys_dirty = g_realloc(ram_list.phys_dirty,
-                                       last_ram_offset() >> TARGET_PAGE_BITS);
-    memset(ram_list.phys_dirty + (new_block->offset >> TARGET_PAGE_BITS),
+    new_ram_size = last_ram_offset() >> TARGET_PAGE_BITS;
+
+    if (new_ram_size > old_ram_size) {
+        ram_list.phys_dirty = g_realloc(ram_list.phys_dirty, new_ram_size);
+        memset(ram_list.phys_dirty + (new_block->offset >> TARGET_PAGE_BITS),
            0, size >> TARGET_PAGE_BITS);
+    }
     cpu_physical_memory_set_dirty_range(new_block->offset, size);
 
     qemu_ram_setup_dump(new_block->host, size);