This value does not need to be calculated as frequent. Only calculate it on demand when query-migrate happened. With that we can remove the variable in MigrationState.
This paves way for fixing this value to include all modules (not only RAM but others too). Reviewed-by: Juraj Marcin <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Peter Xu <[email protected]> --- migration/migration.h | 2 +- migration/migration.c | 25 ++++++++++++------------- 2 files changed, 13 insertions(+), 14 deletions(-) diff --git a/migration/migration.h b/migration/migration.h index 9081e6a612..a5e064a1ac 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -359,7 +359,6 @@ struct MigrationState { /* Timestamp when VM is down (ms) to migrate the last stuff */ int64_t downtime_start; int64_t downtime; - int64_t expected_downtime; bool capabilities[MIGRATION_CAPABILITY__MAX]; int64_t setup_time; @@ -585,6 +584,7 @@ void migration_cancel(void); void migration_populate_vfio_info(MigrationInfo *info); void migration_reset_vfio_bytes_transferred(void); void postcopy_temp_page_reset(PostcopyTmpPage *tmp_page); +int64_t migration_downtime_calc_expected(MigrationState *s); /* * Migration thread waiting for return path thread. Return non-zero if an diff --git a/migration/migration.c b/migration/migration.c index 4e19fe3409..d740d9df85 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -1041,6 +1041,17 @@ static bool migrate_show_downtime(MigrationState *s) return (s->state == MIGRATION_STATUS_COMPLETED) || migration_in_postcopy(); } +/* Return expected downtime (unit: milliseconds) */ +int64_t migration_downtime_calc_expected(MigrationState *s) +{ + if (mig_stats.dirty_sync_count <= 1) { + return migrate_downtime_limit(); + } + + return mig_stats.dirty_bytes_last_sync / + migration_get_switchover_bw(s) * 1000; +} + static void populate_time_info(MigrationInfo *info, MigrationState *s) { info->has_status = true; @@ -1061,7 +1072,7 @@ static void populate_time_info(MigrationInfo *info, MigrationState *s) info->downtime = s->downtime; } else { info->has_expected_downtime = true; - info->expected_downtime = s->expected_downtime; + info->expected_downtime = migration_downtime_calc_expected(s); } } @@ -1649,7 +1660,6 @@ int migrate_init(MigrationState *s, Error **errp) s->mbps = 0.0; s->pages_per_second = 0.0; s->downtime = 0; - s->expected_downtime = 0; s->setup_time = 0; s->start_postcopy = false; s->migration_thread_running = false; @@ -3166,15 +3176,6 @@ static void migration_update_counters(MigrationState *s, s->pages_per_second = (double) transferred_pages / (((double) time_spent / 1000.0)); - /* - * if we haven't sent anything, we don't want to - * recalculate. 10000 is a small enough number for our purposes - */ - if (mig_stats.dirty_pages_rate && transferred > 10000) { - s->expected_downtime = - mig_stats.dirty_bytes_last_sync / switchover_bw_per_ms; - } - migration_rate_reset(); update_iteration_initial_status(s); @@ -3841,8 +3842,6 @@ void migration_start_outgoing(MigrationState *s) bool resume = (s->state == MIGRATION_STATUS_POSTCOPY_RECOVER_SETUP); int ret; - s->expected_downtime = migrate_downtime_limit(); - if (resume) { /* This is a resumed migration */ rate_limit = migrate_max_postcopy_bandwidth(); -- 2.53.0
