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.w...@intel.com> CC: Dr. David Alan Gilbert <dgilb...@redhat.com> CC: Juan Quintela <quint...@redhat.com> CC: Michael S. Tsirkin <m...@redhat.com> --- migration/ram.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/migration/ram.c b/migration/ram.c index e172798..7b4c9b1 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -51,6 +51,8 @@ #include "qemu/rcu_queue.h" #include "migration/colo.h" #include "migration/block.h" +#include "sysemu/balloon.h" +#include "sysemu/sysemu.h" /***********************************************************/ /* ram save/restore */ @@ -208,6 +210,8 @@ 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 */ @@ -775,7 +779,7 @@ unsigned long migration_bitmap_find_dirty(RAMState *rs, RAMBlock *rb, unsigned long *bitmap = rb->bmap; unsigned long next; - if (rs->ram_bulk_stage && start > 0) { + if (rs->ram_bulk_stage && start > 0 && !rs->free_page_support) { next = start + 1; } else { next = find_next_bit(bitmap, size, start); @@ -833,6 +837,10 @@ 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) { @@ -899,6 +907,10 @@ 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 && runstate_is_running()) { + balloon_free_page_start(); + } } /** @@ -1656,6 +1668,8 @@ static void ram_state_reset(RAMState *rs) rs->last_page = 0; rs->last_version = ram_list.version; rs->ram_bulk_stage = true; + rs->free_page_support = balloon_free_page_support() & + !migration_in_postcopy(); } #define MAX_WAIT 50 /* ms, half buffered_file limit */ @@ -2330,6 +2344,9 @@ static int ram_save_iterate(QEMUFile *f, void *opaque) ret = qemu_file_get_error(f); if (ret < 0) { + if (rs->free_page_support) { + balloon_free_page_stop(); + } return ret; } -- 1.8.3.1