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;
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);
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);
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,
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;
* 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));
}
}
(++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);
}
}
}
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),
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);
# 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
'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',
# 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
'*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',
# 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
'*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',
projects / mirror_qemu.git / commitdiff