From 4cbc9c7ffd95d2702cf7ffb3bfdf3f1f0ffdca07 Mon Sep 17 00:00:00 2001 From: Li Qiang Date: Wed, 1 Aug 2018 06:00:20 -0700 Subject: migrate/cpu-throttle: Add max-cpu-throttle migration parameter Currently, the default maximum CPU throttle for migration is 99(CPU_THROTTLE_PCT_MAX). This is too big and can make a remarkable performance effect for the guest. We see a lot of packets latency exceed 500ms when the CPU_THROTTLE_PCT_MAX reached. This patch set adds a new max-cpu-throttle parameter to limit the CPU throttle. Signed-off-by: Li Qiang Reviewed-by: Juan Quintela Reviewed-by: Dr. David Alan Gilbert Signed-off-by: Juan Quintela --- migration/migration.c | 23 ++++++++++++++++++++++- migration/migration.h | 1 + migration/ram.c | 4 +++- 3 files changed, 26 insertions(+), 2 deletions(-) (limited to 'migration') diff --git a/migration/migration.c b/migration/migration.c index b7d9854..570da6c 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -71,6 +71,7 @@ /* Define default autoconverge cpu throttle migration parameters */ #define DEFAULT_MIGRATE_CPU_THROTTLE_INITIAL 20 #define DEFAULT_MIGRATE_CPU_THROTTLE_INCREMENT 10 +#define DEFAULT_MIGRATE_MAX_CPU_THROTTLE 99 /* Migration XBZRLE default cache size */ #define DEFAULT_MIGRATE_XBZRLE_CACHE_SIZE (64 * 1024 * 1024) @@ -697,6 +698,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp) params->xbzrle_cache_size = s->parameters.xbzrle_cache_size; params->has_max_postcopy_bandwidth = true; params->max_postcopy_bandwidth = s->parameters.max_postcopy_bandwidth; + params->has_max_cpu_throttle = true; + params->max_cpu_throttle = s->parameters.max_cpu_throttle; return params; } @@ -1043,6 +1046,15 @@ static bool migrate_params_check(MigrationParameters *params, Error **errp) return false; } + if (params->has_max_cpu_throttle && + (params->max_cpu_throttle < params->cpu_throttle_initial || + params->max_cpu_throttle > 99)) { + error_setg(errp, QERR_INVALID_PARAMETER_VALUE, + "max_cpu_throttle", + "an integer in the range of cpu_throttle_initial to 99"); + return false; + } + return true; } @@ -1110,6 +1122,9 @@ static void migrate_params_test_apply(MigrateSetParameters *params, if (params->has_max_postcopy_bandwidth) { dest->max_postcopy_bandwidth = params->max_postcopy_bandwidth; } + if (params->has_max_cpu_throttle) { + dest->max_cpu_throttle = params->max_cpu_throttle; + } } static void migrate_params_apply(MigrateSetParameters *params, Error **errp) @@ -1185,6 +1200,9 @@ static void migrate_params_apply(MigrateSetParameters *params, Error **errp) if (params->has_max_postcopy_bandwidth) { s->parameters.max_postcopy_bandwidth = params->max_postcopy_bandwidth; } + if (params->has_max_cpu_throttle) { + s->parameters.max_cpu_throttle = params->max_cpu_throttle; + } } void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp) @@ -1962,7 +1980,6 @@ static int64_t migrate_max_postcopy_bandwidth(void) return s->parameters.max_postcopy_bandwidth; } - bool migrate_use_block(void) { MigrationState *s; @@ -3160,6 +3177,9 @@ static Property migration_properties[] = { DEFINE_PROP_SIZE("max-postcopy-bandwidth", MigrationState, parameters.max_postcopy_bandwidth, DEFAULT_MIGRATE_MAX_POSTCOPY_BANDWIDTH), + DEFINE_PROP_UINT8("max-cpu-throttle", MigrationState, + parameters.max_cpu_throttle, + DEFAULT_MIGRATE_MAX_CPU_THROTTLE), /* Migration capabilities */ DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE), @@ -3230,6 +3250,7 @@ static void migration_instance_init(Object *obj) params->has_x_multifd_page_count = true; params->has_xbzrle_cache_size = true; params->has_max_postcopy_bandwidth = true; + params->has_max_cpu_throttle = true; qemu_sem_init(&ms->postcopy_pause_sem, 0); qemu_sem_init(&ms->postcopy_pause_rp_sem, 0); diff --git a/migration/migration.h b/migration/migration.h index 64a7b33..eb0c04a 100644 --- a/migration/migration.h +++ b/migration/migration.h @@ -266,6 +266,7 @@ bool migrate_colo_enabled(void); bool migrate_use_block(void); bool migrate_use_block_incremental(void); +int migrate_max_cpu_throttle(void); bool migrate_use_return_path(void); bool migrate_use_compression(void); diff --git a/migration/ram.c b/migration/ram.c index fa79d0a..1e5c45a 100644 --- a/migration/ram.c +++ b/migration/ram.c @@ -1391,13 +1391,15 @@ static void mig_throttle_guest_down(void) MigrationState *s = migrate_get_current(); uint64_t pct_initial = s->parameters.cpu_throttle_initial; uint64_t pct_icrement = s->parameters.cpu_throttle_increment; + int pct_max = s->parameters.max_cpu_throttle; /* 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(cpu_throttle_get_percentage() + pct_icrement); + cpu_throttle_set(MIN(cpu_throttle_get_percentage() + pct_icrement, + pct_max)); } } -- cgit v1.1