diff options
| -rw-r--r-- | migration/migration.c | 13 | ||||
| -rw-r--r-- | migration/ram.c | 25 | ||||
| -rw-r--r-- | monitor/hmp-cmds.c | 8 | ||||
| -rw-r--r-- | qapi/migration.json | 48 |
4 files changed, 89 insertions, 5 deletions
diff --git a/migration/migration.c b/migration/migration.c index 79f16f6625..f5dbffc442 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -785,6 +785,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) params->cpu_throttle_initial = s->parameters.cpu_throttle_initial; params->has_cpu_throttle_increment = true; params->cpu_throttle_increment = s->parameters.cpu_throttle_increment; + params->has_cpu_throttle_tailslow = true; + params->cpu_throttle_tailslow = s->parameters.cpu_throttle_tailslow; params->has_tls_creds = true; params->tls_creds = g_strdup(s->parameters.tls_creds); params->has_tls_hostname = true; @@ -1327,6 +1329,10 @@ static void migrate_params_test_apply(MigrateSetParameters *params, dest->cpu_throttle_increment = params->cpu_throttle_increment; } + if (params->has_cpu_throttle_tailslow) { + dest->cpu_throttle_tailslow = params->cpu_throttle_tailslow; + } + if (params->has_tls_creds) { assert(params->tls_creds->type == QTYPE_QSTRING); dest->tls_creds = g_strdup(params->tls_creds->u.s); @@ -1415,6 +1421,10 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) s->parameters.cpu_throttle_increment = params->cpu_throttle_increment; } + if (params->has_cpu_throttle_tailslow) { + s->parameters.cpu_throttle_tailslow = params->cpu_throttle_tailslow; + } + if (params->has_tls_creds) { g_free(s->parameters.tls_creds); assert(params->tls_creds->type == QTYPE_QSTRING); @@ -3597,6 +3607,8 @@ static Property migration_properties[] = { DEFINE_PROP_UINT8("x-cpu-throttle-increment", MigrationState, parameters.cpu_throttle_increment, DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT), + DEFINE_PROP_BOOL("x-cpu-throttle-tailslow", MigrationState, + parameters.cpu_throttle_tailslow, false), DEFINE_PROP_SIZE("x-max-bandwidth", MigrationState, parameters.max_bandwidth, MAX_THROTTLE), DEFINE_PROP_UINT64("x-downtime-limit", MigrationState, @@ -3703,6 +3715,7 @@ static void migration_instance_init(Object *obj) params->has_throttle_trigger_threshold = true; params->has_cpu_throttle_initial = true; params->has_cpu_throttle_increment = true; + params->has_cpu_throttle_tailslow = true; params->has_max_bandwidth = true; params->has_downtime_limit = true; params->has_x_checkpoint_delay = true; diff --git a/migration/ram.c b/migration/ram.c index 53166fc279..52fc032b83 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -616,20 +616,34 @@ static size_t save_page_header(RAMState *rs, QEMUFile *f, RAMBlock *block, * able to complete migration. Some workloads dirty memory way too * fast and will not effectively converge, even with auto-converge. */ -static void mig_throttle_guest_down(void) +static void mig_throttle_guest_down(uint64_t bytes_dirty_period, + uint64_t bytes_dirty_threshold) { MigrationState *s = migrate_get_current(); uint64_t pct_initial = s->parameters.cpu_throttle_initial; - uint64_t pct_icrement = s->parameters.cpu_throttle_increment; + uint64_t pct_increment = s->parameters.cpu_throttle_increment; + bool pct_tailslow = s->parameters.cpu_throttle_tailslow; int pct_max = s->parameters.max_cpu_throttle; + uint64_t throttle_now = cpu_throttle_get_percentage(); + uint64_t cpu_now, cpu_ideal, throttle_inc; + /* We have not started throttling yet. Let's start it. */ if (!cpu_throttle_active()) { cpu_throttle_set(pct_initial); } else { /* Throttling already on, just increase the rate */ - cpu_throttle_set(MIN(cpu_throttle_get_percentage() + pct_icrement, - pct_max)); + if (!pct_tailslow) { + throttle_inc = pct_increment; + } else { + /* Compute the ideal CPU percentage used by Guest, which may + * make the dirty rate match the dirty rate threshold. */ + cpu_now = 100 - throttle_now; + cpu_ideal = cpu_now * (bytes_dirty_threshold * 1.0 / + bytes_dirty_period); + throttle_inc = MIN(cpu_now - cpu_ideal, pct_increment); + } + cpu_throttle_set(MIN(throttle_now + throttle_inc, pct_max)); } } @@ -919,7 +933,8 @@ static void migration_trigger_throttle(RAMState *rs) (++rs->dirty_rate_high_cnt >= 2)) { trace_migration_throttle(); rs->dirty_rate_high_cnt = 0; - mig_throttle_guest_down(); + mig_throttle_guest_down(bytes_dirty_period, + bytes_dirty_threshold); } } } diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c index 1552dee489..ade1f85e0c 100644 --- a/monitor/hmp-cmds.c +++ b/monitor/hmp-cmds.c @@ -420,6 +420,10 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict) monitor_printf(mon, "%s: %u\n", MigrationParameter_str(MIGRATION_PARAMETER_CPU_THROTTLE_INCREMENT), params->cpu_throttle_increment); + assert(params->has_cpu_throttle_tailslow); + monitor_printf(mon, "%s: %s\n", + MigrationParameter_str(MIGRATION_PARAMETER_CPU_THROTTLE_TAILSLOW), + params->cpu_throttle_tailslow ? "on" : "off"); assert(params->has_max_cpu_throttle); monitor_printf(mon, "%s: %u\n", MigrationParameter_str(MIGRATION_PARAMETER_MAX_CPU_THROTTLE), @@ -1275,6 +1279,10 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict) p->has_cpu_throttle_increment = true; visit_type_int(v, param, &p->cpu_throttle_increment, &err); break; + case MIGRATION_PARAMETER_CPU_THROTTLE_TAILSLOW: + p->has_cpu_throttle_tailslow = true; + visit_type_bool(v, param, &p->cpu_throttle_tailslow, &err); + break; case MIGRATION_PARAMETER_MAX_CPU_THROTTLE: p->has_max_cpu_throttle = true; visit_type_int(v, param, &p->max_cpu_throttle, &err); diff --git a/qapi/migration.json b/qapi/migration.json index eca2981d0a..ee6c5a0cae 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -552,6 +552,21 @@ # auto-converge detects that migration is not making # progress. The default value is 10. (Since 2.7) # +# @cpu-throttle-tailslow: Make CPU throttling slower at tail stage +# At the tail stage of throttling, the Guest is very +# sensitive to CPU percentage while the @cpu-throttle +# -increment is excessive usually at tail stage. +# If this parameter is true, we will compute the ideal +# CPU percentage used by the Guest, which may exactly make +# the dirty rate match the dirty rate threshold. Then we +# will choose a smaller throttle increment between the +# one specified by @cpu-throttle-increment and the one +# generated by ideal CPU percentage. +# Therefore, it is compatible to traditional throttling, +# meanwhile the throttle increment won't be excessive +# at tail stage. +# The default value is false. (Since 5.1) +# # @tls-creds: ID of the 'tls-creds' object that provides credentials for # establishing a TLS connection over the migration data channel. # On the outgoing side of the migration, the credentials must @@ -631,6 +646,7 @@ 'compress-level', 'compress-threads', 'decompress-threads', 'compress-wait-thread', 'throttle-trigger-threshold', 'cpu-throttle-initial', 'cpu-throttle-increment', + 'cpu-throttle-tailslow', 'tls-creds', 'tls-hostname', 'tls-authz', 'max-bandwidth', 'downtime-limit', 'x-checkpoint-delay', 'block-incremental', 'multifd-channels', @@ -676,6 +692,21 @@ # auto-converge detects that migration is not making # progress. The default value is 10. (Since 2.7) # +# @cpu-throttle-tailslow: Make CPU throttling slower at tail stage +# At the tail stage of throttling, the Guest is very +# sensitive to CPU percentage while the @cpu-throttle +# -increment is excessive usually at tail stage. +# If this parameter is true, we will compute the ideal +# CPU percentage used by the Guest, which may exactly make +# the dirty rate match the dirty rate threshold. Then we +# will choose a smaller throttle increment between the +# one specified by @cpu-throttle-increment and the one +# generated by ideal CPU percentage. +# Therefore, it is compatible to traditional throttling, +# meanwhile the throttle increment won't be excessive +# at tail stage. +# The default value is false. (Since 5.1) +# # @tls-creds: ID of the 'tls-creds' object that provides credentials # for establishing a TLS connection over the migration data # channel. On the outgoing side of the migration, the credentials @@ -763,6 +794,7 @@ '*throttle-trigger-threshold': 'int', '*cpu-throttle-initial': 'int', '*cpu-throttle-increment': 'int', + '*cpu-throttle-tailslow': 'bool', '*tls-creds': 'StrOrNull', '*tls-hostname': 'StrOrNull', '*tls-authz': 'StrOrNull', @@ -834,6 +866,21 @@ # auto-converge detects that migration is not making # progress. (Since 2.7) # +# @cpu-throttle-tailslow: Make CPU throttling slower at tail stage +# At the tail stage of throttling, the Guest is very +# sensitive to CPU percentage while the @cpu-throttle +# -increment is excessive usually at tail stage. +# If this parameter is true, we will compute the ideal +# CPU percentage used by the Guest, which may exactly make +# the dirty rate match the dirty rate threshold. Then we +# will choose a smaller throttle increment between the +# one specified by @cpu-throttle-increment and the one +# generated by ideal CPU percentage. +# Therefore, it is compatible to traditional throttling, +# meanwhile the throttle increment won't be excessive +# at tail stage. +# The default value is false. (Since 5.1) +# # @tls-creds: ID of the 'tls-creds' object that provides credentials # for establishing a TLS connection over the migration data # channel. On the outgoing side of the migration, the credentials @@ -921,6 +968,7 @@ '*throttle-trigger-threshold': 'uint8', '*cpu-throttle-initial': 'uint8', '*cpu-throttle-increment': 'uint8', + '*cpu-throttle-tailslow': 'bool', '*tls-creds': 'str', '*tls-hostname': 'str', '*tls-authz': 'str', |