ram: create trace event for migration sync bitmap

Signed-off-by: Juan Quintela <quintela@redhat.com>

Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch_init.c b/arch_init.c
index 3a5fecc..cec3ead 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -45,6 +45,7 @@
 #include "hw/pcspk.h"
 #include "qemu/page_cache.h"
 #include "qmp-commands.h"
+#include "trace.h"
 
 #ifdef DEBUG_ARCH_INIT
 #define DPRINTF(fmt, ...) \
@@ -358,7 +359,12 @@
 
 static void migration_bitmap_sync(void)
 {
+    uint64_t num_dirty_pages_init = ram_list.dirty_pages;
+
+    trace_migration_bitmap_sync_start();
     memory_global_sync_dirty_bitmap(get_system_memory());
+    trace_migration_bitmap_sync_end(ram_list.dirty_pages
+                                    - num_dirty_pages_init);
 }