Add a helper to be able to return an estimate of switchover bw, called migration_get_switchover_bw(). Use it to sligitly simplify the current code.
This will be used in new codes later to remove expected_downtime. Signed-off-by: Peter Xu <[email protected]> --- migration/migration.h | 1 + migration/migration.c | 43 ++++++++++++++++++++++--------------------- 2 files changed, 23 insertions(+), 21 deletions(-) diff --git a/migration/migration.h b/migration/migration.h index b6888daced..bf3ee6cc07 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -586,6 +586,7 @@ 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 ad8a824585..56d605ede9 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -984,6 +984,21 @@ void migrate_send_rp_resume_ack(MigrationIncomingState *mis, uint32_t value) migrate_send_rp_message(mis, MIG_RP_MSG_RESUME_ACK, sizeof(buf), &buf); } +/* + * Returns the estimated switchover bandwidth (unit: bytes / seconds) + */ +static double migration_get_switchover_bw(MigrationState *s) +{ + uint64_t switchover_bw = migrate_avail_switchover_bandwidth(); + + if (switchover_bw) { + /* If user specified, prioritize this value and don't estimate */ + return (double)switchover_bw; + } + + return s->mbps / 8 * 1000 * 1000; +} + bool migration_is_running(void) { MigrationState *s = current_migration; @@ -3126,37 +3141,22 @@ static void migration_update_counters(MigrationState *s, { uint64_t transferred, transferred_pages, time_spent; uint64_t current_bytes; /* bytes transferred since the beginning */ - uint64_t switchover_bw; - /* Expected bandwidth when switching over to destination QEMU */ - double expected_bw_per_ms; - double bandwidth; + double switchover_bw; if (current_time < s->iteration_start_time + BUFFER_DELAY) { return; } - switchover_bw = migrate_avail_switchover_bandwidth(); current_bytes = migration_transferred_bytes(); transferred = current_bytes - s->iteration_initial_bytes; time_spent = current_time - s->iteration_start_time; - bandwidth = (double)transferred / time_spent; - - if (switchover_bw) { - /* - * If the user specified a switchover bandwidth, let's trust the - * user so that can be more accurate than what we estimated. - */ - expected_bw_per_ms = (double)switchover_bw / 1000; - } else { - /* If the user doesn't specify bandwidth, we use the estimated */ - expected_bw_per_ms = bandwidth; - } - - s->threshold_size = expected_bw_per_ms * migrate_downtime_limit(); - s->mbps = (((double) transferred * 8.0) / ((double) time_spent / 1000.0)) / 1000.0 / 1000.0; + /* NOTE: only update this after bandwidth (s->mbps) updated */ + switchover_bw = migration_get_switchover_bw(s) / 1000; + s->threshold_size = switchover_bw * migrate_downtime_limit(); + transferred_pages = ram_get_total_transferred_pages() - s->iteration_initial_pages; s->pages_per_second = (double) transferred_pages / @@ -3178,7 +3178,8 @@ static void migration_update_counters(MigrationState *s, trace_migrate_transferred(transferred, time_spent, /* Both in unit bytes/ms */ - bandwidth, switchover_bw / 1000, + (uint64_t)s->mbps, + (uint64_t)switchover_bw, s->threshold_size); } -- 2.50.1
