@@ -51,6 +51,7 @@
#include "qemu/rcu_queue.h"
#include "migration/colo.h"
#include "migration/block.h"
+#include "sysemu/balloon.h"
/***********************************************************/
/* ram save/restore */
@@ -213,6 +214,8 @@ struct RAMState {
uint32_t last_version;
/* We are in the first round */
bool ram_bulk_stage;
+ /* The free pages optimization feature is supported */
+ bool free_page_support;
/* How many times we have dirty too many pages */
int dirty_rate_high_cnt;
/* these variables are used for bitmap sync */
@@ -841,6 +844,10 @@ static void migration_bitmap_sync(RAMState *rs)
int64_t end_time;
uint64_t bytes_xfer_now;
+ if (rs->free_page_support) {
+ balloon_free_page_stop();
+ }
+
ram_counters.dirty_sync_count++;
if (!rs->time_last_bitmap_sync) {
@@ -907,6 +914,10 @@ static void migration_bitmap_sync(RAMState *rs)
if (migrate_use_events()) {
qapi_event_send_migration_pass(ram_counters.dirty_sync_count, NULL);
}
+
+ if (rs->free_page_support) {
+ balloon_free_page_start();
+ }
}
/**
@@ -1663,7 +1674,17 @@ static void ram_state_reset(RAMState *rs)
rs->last_sent_block = NULL;
rs->last_page = 0;
rs->last_version = ram_list.version;
- rs->ram_bulk_stage = true;
+ rs->free_page_support = balloon_free_page_support() && !migrate_postcopy();
+ if (rs->free_page_support) {
+ /*
+ * When the free page optimization is used, not all the pages are
+ * treated as dirty pages (via migration_bitmap_find_dirty), which need
+ * to be sent. So disable ram_bulk_stage in this case.
+ */
+ rs->ram_bulk_stage = false;
+ } else {
+ rs->ram_bulk_stage = true;
+ }
}
#define MAX_WAIT 50 /* ms, half buffered_file limit */
@@ -2369,6 +2390,9 @@ out:
ret = qemu_file_get_error(f);
if (ret < 0) {
+ if (rs->free_page_support) {
+ balloon_free_page_stop();
+ }
return ret;
}
Start the free page optimization after the migration bitmap is synchronized. This can't be used in the stop© phase since the guest is paused. Make sure the guest reporting has stopped before synchronizing the migration dirty bitmap. Currently, the optimization is added to precopy only. Signed-off-by: Wei Wang <wei.w.wang@intel.com> CC: Dr. David Alan Gilbert <dgilbert@redhat.com> CC: Juan Quintela <quintela@redhat.com> CC: Michael S. Tsirkin <mst@redhat.com> --- migration/ram.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-)