diff mbox series

[RESEND,v3,04/10] qapi/migration: Introduce x-vcpu-dirty-limit-period parameter

Message ID d10a1ef4c7cc99beb6050af1a4374dbecb9db5f1.1670087275.git.huangy81@chinatelecom.cn
State New
Headers show
Series migration: introduce dirtylimit capability | expand

Commit Message

Hyman Huang Dec. 3, 2022, 5:09 p.m. UTC 
From: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>

Introduce "x-vcpu-dirty-limit-period" migration experimental
parameter, which is in the range of 1 to 1000ms and used to
make dirtyrate calculation period configurable.

Currently with the "x-vcpu-dirty-limit-period" varies, the
total time of live migration changes, test results show the
optimal value of "x-vcpu-dirty-limit-period" ranges from
500ms to 1000 ms. "x-vcpu-dirty-limit-period" should be made
stable once it proves best value can not be determined with
developer's experiments.

Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
---
 migration/migration.c | 26 ++++++++++++++++++++++++++
 monitor/hmp-cmds.c    |  8 ++++++++
 qapi/migration.json   | 34 +++++++++++++++++++++++++++-------
 3 files changed, 61 insertions(+), 7 deletions(-)

Comments

Markus Armbruster Jan. 11, 2023, 1:55 p.m. UTC | #1 
huangy81@chinatelecom.cn writes:

> From: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>
>
> Introduce "x-vcpu-dirty-limit-period" migration experimental
> parameter, which is in the range of 1 to 1000ms and used to
> make dirtyrate calculation period configurable.
>
> Currently with the "x-vcpu-dirty-limit-period" varies, the
> total time of live migration changes, test results show the
> optimal value of "x-vcpu-dirty-limit-period" ranges from
> 500ms to 1000 ms. "x-vcpu-dirty-limit-period" should be made
> stable once it proves best value can not be determined with
> developer's experiments.

I'm not a native speaker, but let me try to polish your prose anyway:

  The value of "x-vcpu-dirty-limit-period" affects how long live migration
  takes.  In my testing, the optimal value of "x-vcpu-dirty-limit-period"
  ranges from 500ms to 1000 ms.  If we can find a single value that is
  good enough for all use cases that matter, "x-vcpu-dirty-limit-period"
  can go away.  Else, "x-vcpu-dirty-limit-period" should be made stable.

Does this capture your intent?

> Signed-off-by: Hyman Huang(黄勇) <huangy81@chinatelecom.cn>

[...]

> diff --git a/qapi/migration.json b/qapi/migration.json
> index 88ecf86..c428bcd 100644
> --- a/qapi/migration.json
> +++ b/qapi/migration.json
> @@ -776,8 +776,13 @@
>  #                        block device name if there is one, and to their node name
>  #                        otherwise. (Since 5.2)
>  #
> +# @x-vcpu-dirty-limit-period: Periodic time (in milliseconds) of dirty limit during
> +#                             live migration. Should be in the range 1 to 1000ms,
> +#                             defaults to 1000ms. (Since 7.3)

8.0, not 7.3, unless we change our versioning habits.  More of the same
below and later in this series; I'm not flagging it again.

> +#
>  # Features:
> -# @unstable: Member @x-checkpoint-delay is experimental.
> +# @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period
> +#            are experimental.
>  #
>  # Since: 2.4
>  ##

[...]
diff mbox series

Patch

diff --git a/migration/migration.c b/migration/migration.c
index f485eea..1439d61 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -116,6 +116,8 @@ 
 #define DEFAULT_MIGRATE_ANNOUNCE_ROUNDS    5
 #define DEFAULT_MIGRATE_ANNOUNCE_STEP    100
 
+#define DEFAULT_MIGRATE_VCPU_DIRTY_LIMIT_PERIOD     1000    /* microsecond */
+
 static NotifierList migration_state_notifiers =
     NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);
 
@@ -963,6 +965,9 @@  MigrationParameters *qmp_query_migrate_parameters(Error **errp)
                        s->parameters.block_bitmap_mapping);
     }
 
+    params->has_x_vcpu_dirty_limit_period = true;
+    params->x_vcpu_dirty_limit_period = s->parameters.x_vcpu_dirty_limit_period;
+
     return params;
 }
 
@@ -1582,6 +1587,15 @@  static bool migrate_params_check(MigrationParameters *params, Error **errp)
     }
 #endif
 
+    if (params->has_x_vcpu_dirty_limit_period &&
+        (params->x_vcpu_dirty_limit_period < 1 ||
+         params->x_vcpu_dirty_limit_period > 1000)) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
+                   "x-vcpu-dirty-limit-period",
+                   "a value between 1 and 1000");
+        return false;
+    }
+
     return true;
 }
 
@@ -1681,6 +1695,10 @@  static void migrate_params_test_apply(MigrateSetParameters *params,
         dest->has_block_bitmap_mapping = true;
         dest->block_bitmap_mapping = params->block_bitmap_mapping;
     }
+
+    if (params->has_x_vcpu_dirty_limit_period) {
+        dest->x_vcpu_dirty_limit_period = params->x_vcpu_dirty_limit_period;
+    }
 }
 
 static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
@@ -1803,6 +1821,10 @@  static void migrate_params_apply(MigrateSetParameters *params, Error **errp)
             QAPI_CLONE(BitmapMigrationNodeAliasList,
                        params->block_bitmap_mapping);
     }
+    if (params->has_x_vcpu_dirty_limit_period) {
+        s->parameters.x_vcpu_dirty_limit_period =
+            params->x_vcpu_dirty_limit_period;
+    }
 }
 
 void qmp_migrate_set_parameters(MigrateSetParameters *params, Error **errp)
@@ -4404,6 +4426,9 @@  static Property migration_properties[] = {
     DEFINE_PROP_STRING("tls-creds", MigrationState, parameters.tls_creds),
     DEFINE_PROP_STRING("tls-hostname", MigrationState, parameters.tls_hostname),
     DEFINE_PROP_STRING("tls-authz", MigrationState, parameters.tls_authz),
+    DEFINE_PROP_UINT64("x-vcpu-dirty-limit-period", MigrationState,
+                       parameters.x_vcpu_dirty_limit_period,
+                       DEFAULT_MIGRATE_VCPU_DIRTY_LIMIT_PERIOD),
 
     /* Migration capabilities */
     DEFINE_PROP_MIG_CAP("x-xbzrle", MIGRATION_CAPABILITY_XBZRLE),
@@ -4495,6 +4520,7 @@  static void migration_instance_init(Object *obj)
     params->has_tls_creds = true;
     params->has_tls_hostname = true;
     params->has_tls_authz = true;
+    params->has_x_vcpu_dirty_limit_period = true;
 
     qemu_sem_init(&ms->postcopy_pause_sem, 0);
     qemu_sem_init(&ms->postcopy_pause_rp_sem, 0);
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 01b789a..a3170ca 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -513,6 +513,10 @@  void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
                 }
             }
         }
+
+        monitor_printf(mon, "%s: %" PRIu64 " ms\n",
+        MigrationParameter_str(MIGRATION_PARAMETER_X_VCPU_DIRTY_LIMIT_PERIOD),
+        params->x_vcpu_dirty_limit_period);
     }
 
     qapi_free_MigrationParameters(params);
@@ -1332,6 +1336,10 @@  void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
         error_setg(&err, "The block-bitmap-mapping parameter can only be set "
                    "through QMP");
         break;
+    case MIGRATION_PARAMETER_X_VCPU_DIRTY_LIMIT_PERIOD:
+        p->has_x_vcpu_dirty_limit_period = true;
+        visit_type_size(v, param, &p->x_vcpu_dirty_limit_period, &err);
+        break;
     default:
         assert(0);
     }
diff --git a/qapi/migration.json b/qapi/migration.json
index 88ecf86..c428bcd 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -776,8 +776,13 @@ 
 #                        block device name if there is one, and to their node name
 #                        otherwise. (Since 5.2)
 #
+# @x-vcpu-dirty-limit-period: Periodic time (in milliseconds) of dirty limit during
+#                             live migration. Should be in the range 1 to 1000ms,
+#                             defaults to 1000ms. (Since 7.3)
+#
 # Features:
-# @unstable: Member @x-checkpoint-delay is experimental.
+# @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period
+#            are experimental.
 #
 # Since: 2.4
 ##
@@ -795,8 +800,9 @@ 
            'multifd-channels',
            'xbzrle-cache-size', 'max-postcopy-bandwidth',
            'max-cpu-throttle', 'multifd-compression',
-           'multifd-zlib-level' ,'multifd-zstd-level',
-           'block-bitmap-mapping' ] }
+           'multifd-zlib-level', 'multifd-zstd-level',
+           'block-bitmap-mapping',
+           { 'name': 'x-vcpu-dirty-limit-period', 'features': ['unstable'] } ] }
 
 ##
 # @MigrateSetParameters:
@@ -941,8 +947,13 @@ 
 #                        block device name if there is one, and to their node name
 #                        otherwise. (Since 5.2)
 #
+# @x-vcpu-dirty-limit-period: Periodic time (in milliseconds) of dirty limit during
+#                             live migration. Should be in the range 1 to 1000ms,
+#                             defaults to 1000ms. (Since 7.3)
+#
 # Features:
-# @unstable: Member @x-checkpoint-delay is experimental.
+# @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period
+#            are experimental.
 #
 # Since: 2.4
 ##
@@ -976,7 +987,9 @@ 
             '*multifd-compression': 'MultiFDCompression',
             '*multifd-zlib-level': 'uint8',
             '*multifd-zstd-level': 'uint8',
-            '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } }
+            '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ],
+            '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
+                                            'features': [ 'unstable' ] } } }
 
 ##
 # @migrate-set-parameters:
@@ -1141,8 +1154,13 @@ 
 #                        block device name if there is one, and to their node name
 #                        otherwise. (Since 5.2)
 #
+# @x-vcpu-dirty-limit-period: Periodic time (in milliseconds) of dirty limit during
+#                             live migration. Should be in the range 1 to 1000ms,
+#                             defaults to 1000ms. (Since 7.3)
+#
 # Features:
-# @unstable: Member @x-checkpoint-delay is experimental.
+# @unstable: Members @x-checkpoint-delay and @x-vcpu-dirty-limit-period
+#            are experimental.
 #
 # Since: 2.4
 ##
@@ -1174,7 +1192,9 @@ 
             '*multifd-compression': 'MultiFDCompression',
             '*multifd-zlib-level': 'uint8',
             '*multifd-zstd-level': 'uint8',
-            '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ] } }
+            '*block-bitmap-mapping': [ 'BitmapMigrationNodeAlias' ],
+            '*x-vcpu-dirty-limit-period': { 'type': 'uint64',
+                                            'features': [ 'unstable' ] } } }
 
 ##
 # @query-migrate-parameters: