From 7e555c6c58f095c9286814c3f9cd06196feba8a1 Mon Sep 17 00:00:00 2001 From: Dr. David Alan Gilbert Date: Wed, 13 Jun 2018 11:26:40 +0100 Subject: migration/postcopy: Add max-postcopy-bandwidth parameter Limit the background transfer bandwidth during the postcopy phase to the value set on this new parameter. The default, 0, corresponds to the existing behaviour which is unlimited bandwidth. Signed-off-by: Dr. David Alan Gilbert Message-Id: <20180613102642.23995-2-dgilbert@redhat.com> Reviewed-by: Peter Xu Signed-off-by: Dr. David Alan Gilbert --- migration/migration.c | 35 ++++++++++++++++++++++++++++++++++- 1 file changed, 34 insertions(+), 1 deletion(-) (limited to 'migration') diff --git a/migration/migration.c b/migration/migration.c index 1e99ec9b7e..3a50d4c35c 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); @@ -3042,6 +3071,9 @@ 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), @@ -3110,6 +3142,7 @@ 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); -- cgit v1.2.3-55-g7522