diff options
Diffstat (limited to 'migration/migration.c')
| -rw-r--r-- | migration/migration.c | 73 |
1 files changed, 66 insertions, 7 deletions
diff --git a/migration/migration.c b/migration/migration.c index 1e99ec9b7e..e1eaa97df4 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -82,6 +82,11 @@ #define DEFAULT_MIGRATE_MULTIFD_CHANNELS 2 #define DEFAULT_MIGRATE_MULTIFD_PAGE_COUNT 16 +/* Background transfer rate for postcopy, 0 means unlimited, note + * that page requests can still exceed this limit. + */ +#define DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH 0 + static NotifierList migration_state_notifiers = NOTIFIER_LIST_INITIALIZER(migration_state_notifiers); @@ -659,6 +664,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) params->x_multifd_page_count = s->parameters.x_multifd_page_count; params->has_xbzrle_cache_size = true; params->xbzrle_cache_size = s->parameters.xbzrle_cache_size; + params->has_max_postcopy_bandwidth = true; + params->max_postcopy_bandwidth = s->parameters.max_postcopy_bandwidth; return params; } @@ -1066,6 +1073,9 @@ static void migrate_params_test_apply(MigrateSetParameters *params, if (params->has_xbzrle_cache_size) { dest->xbzrle_cache_size = params->xbzrle_cache_size; } + if (params->has_max_postcopy_bandwidth) { + dest->max_postcopy_bandwidth = params->max_postcopy_bandwidth; + } } static void migrate_params_apply(MigrateSetParameters *params, Error **errp) @@ -1138,6 +1148,9 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) s->parameters.xbzrle_cache_size = params->xbzrle_cache_size; xbzrle_cache_resize(params->xbzrle_cache_size, errp); } + if (params->has_max_postcopy_bandwidth) { + s->parameters.max_postcopy_bandwidth = params->max_postcopy_bandwidth; + } } void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp) @@ -1887,6 +1900,16 @@ int64_t migrate_xbzrle_cache_size(void) return s->parameters.xbzrle_cache_size; } +static int64_t migrate_max_postcopy_bandwidth(void) +{ + MigrationState *s; + + s = migrate_get_current(); + + return s->parameters.max_postcopy_bandwidth; +} + + bool migrate_use_block(void) { MigrationState *s; @@ -2226,6 +2249,7 @@ static int postcopy_start(MigrationState *ms) QIOChannelBuffer *bioc; QEMUFile *fb; int64_t time_at_stop = qemu_clock_get_ms(QEMU_CLOCK_REALTIME); + int64_t bandwidth = migrate_max_postcopy_bandwidth(); bool restart_block = false; int cur_state = MIGRATION_STATUS_ACTIVE; if (!migrate_pause_before_switchover()) { @@ -2280,7 +2304,12 @@ static int postcopy_start(MigrationState *ms) * will notice we're in POSTCOPY_ACTIVE and not actually * wrap their state up here */ - qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX); + /* 0 max-postcopy-bandwidth means unlimited */ + if (!bandwidth) { + qemu_file_set_rate_limit(ms->to_dst_file, INT64_MAX); + } else { + qemu_file_set_rate_limit(ms->to_dst_file, bandwidth / XFER_LIMIT_RATIO); + } if (migrate_postcopy_ram()) { /* Ping just for debugging, helps line traces up */ qemu_savevm_send_ping(ms->to_dst_file, 2); @@ -2717,8 +2746,7 @@ static void migration_update_counters(MigrationState *s, * recalculate. 10000 is a small enough number for our purposes */ if (ram_counters.dirty_pages_rate && transferred > 10000) { - s->expected_downtime = ram_counters.dirty_pages_rate * - qemu_target_page_size() / bandwidth; + s->expected_downtime = ram_counters.remaining / bandwidth; } qemu_file_reset_rate_limit(s->to_dst_file); @@ -2823,6 +2851,16 @@ static void migration_iteration_finish(MigrationState *s) qemu_mutex_unlock_iothread(); } +void migration_make_urgent_request(void) +{ + qemu_sem_post(&migrate_get_current()->rate_limit_sem); +} + +void migration_consume_urgent_request(void) +{ + qemu_sem_wait(&migrate_get_current()->rate_limit_sem); +} + /* * Master migration thread on the source VM. * It drives the migration and pumps the data down the outgoing channel. @@ -2832,6 +2870,7 @@ static void *migration_thread(void *opaque) MigrationState *s = opaque; int64_t setup_start = qemu_clock_get_ms(QEMU_CLOCK_HOST); MigThrError thr_error; + bool urgent = false; rcu_register_thread(); @@ -2872,7 +2911,7 @@ static void *migration_thread(void *opaque) s->state == MIGRATION_STATUS_POSTCOPY_ACTIVE) { int64_t current_time; - if (!qemu_file_rate_limit(s->to_dst_file)) { + if (urgent || !qemu_file_rate_limit(s->to_dst_file)) { MigIterateState iter_state = migration_iteration_run(s); if (iter_state == MIG_ITERATE_SKIP) { continue; @@ -2903,10 +2942,24 @@ static void *migration_thread(void *opaque) migration_update_counters(s, current_time); + urgent = false; if (qemu_file_rate_limit(s->to_dst_file)) { - /* usleep expects microseconds */ - g_usleep((s->iteration_start_time + BUFFER_DELAY - - current_time) * 1000); + /* Wait for a delay to do rate limiting OR + * something urgent to post the semaphore. + */ + int ms = s->iteration_start_time + BUFFER_DELAY - current_time; + trace_migration_thread_ratelimit_pre(ms); + if (qemu_sem_timedwait(&s->rate_limit_sem, ms) == 0) { + /* We were worken by one or more urgent things but + * the timedwait will have consumed one of them. + * The service routine for the urgent wake will dec + * the semaphore itself for each item it consumes, + * so add this one we just eat back. + */ + qemu_sem_post(&s->rate_limit_sem); + urgent = true; + } + trace_migration_thread_ratelimit_post(urgent); } } @@ -3042,6 +3095,9 @@ static Property migration_properties[] = { DEFINE_PROP_SIZE("xbzrle-cache-size", MigrationState, parameters.xbzrle_cache_size, DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE), + DEFINE_PROP_SIZE("max-postcopy-bandwidth", MigrationState, + parameters.max_postcopy_bandwidth, + DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH), /* Migration capabilities */ DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE), @@ -3077,6 +3133,7 @@ static void migration_instance_finalize(Object *obj) qemu_mutex_destroy(&ms->qemu_file_lock); g_free(params->tls_hostname); g_free(params->tls_creds); + qemu_sem_destroy(&ms->rate_limit_sem); qemu_sem_destroy(&ms->pause_sem); qemu_sem_destroy(&ms->postcopy_pause_sem); qemu_sem_destroy(&ms->postcopy_pause_rp_sem); @@ -3110,10 +3167,12 @@ static void migration_instance_init(Object *obj) params->has_x_multifd_channels = true; params->has_x_multifd_page_count = true; params->has_xbzrle_cache_size = true; + params->has_max_postcopy_bandwidth = true; qemu_sem_init(&ms->postcopy_pause_sem, 0); qemu_sem_init(&ms->postcopy_pause_rp_sem, 0); qemu_sem_init(&ms->rp_state.rp_sem, 0); + qemu_sem_init(&ms->rate_limit_sem, 0); qemu_mutex_init(&ms->qemu_file_lock); } |