[Qemu-devel] [PATCH 05/13] migration: Create x-multifd-threads parameter

[Juan Quintela <quintela@redhat.com>]

Indicates the number of threads that we would create.  By default we
create 2 threads.

Signed-off-by: Juan Quintela <quintela@redhat.com>
---
 hmp.c                         |  8 ++++++++
 include/migration/migration.h |  2 ++
 migration/migration.c         | 30 +++++++++++++++++++++++++++++-
 qapi-schema.json              | 19 ++++++++++++++++---
 4 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/hmp.c b/hmp.c
index d510236..2a40f1f 100644
--- a/hmp.c
+++ b/hmp.c
@@ -286,6 +286,9 @@ void hmp_info_migrate_parameters(Monitor *mon, const QDict *qdict)
         monitor_printf(mon, " %s: %" PRId64,
             MigrationParameter_lookup[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT],
             params->x_cpu_throttle_increment);
+        monitor_printf(mon, " %s: %" PRId64,
+            MigrationParameter_lookup[MIGRATION_PARAMETER_X_MULTIFD_THREADS],
+            params->x_multifd_threads);
         monitor_printf(mon, "\n");
     }

@@ -1242,6 +1245,7 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
     bool has_decompress_threads = false;
     bool has_x_cpu_throttle_initial = false;
     bool has_x_cpu_throttle_increment = false;
+    bool has_x_multifd_threads = false;
     int i;

     for (i = 0; i < MIGRATION_PARAMETER__MAX; i++) {
@@ -1262,12 +1266,16 @@ void hmp_migrate_set_parameter(Monitor *mon, const QDict *qdict)
             case MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT:
                 has_x_cpu_throttle_increment = true;
                 break;
+            case MIGRATION_PARAMETER_X_MULTIFD_THREADS:
+                has_x_multifd_threads = true;
+                break;
             }
             qmp_migrate_set_parameters(has_compress_level, value,
                                        has_compress_threads, value,
                                        has_decompress_threads, value,
                                        has_x_cpu_throttle_initial, value,
                                        has_x_cpu_throttle_increment, value,
+                                       has_x_multifd_threads, value,
                                        &err);
             break;
         }
diff --git a/include/migration/migration.h b/include/migration/migration.h
index a626b7d..19d535d 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -219,6 +219,8 @@ bool migration_in_postcopy(MigrationState *);
 bool migration_in_postcopy_after_devices(MigrationState *);
 MigrationState *migrate_get_current(void);

+int migrate_multifd_threads(void);
+
 void migrate_compress_threads_create(void);
 void migrate_compress_threads_join(void);
 void migrate_decompress_threads_create(void);
diff --git a/migration/migration.c b/migration/migration.c
index 92e6dc4..29e43ff 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -56,6 +56,8 @@
 /* Migration XBZRLE default cache size */
 #define DEFAULT_MIGRATE_CACHE_SIZE (64 * 1024 * 1024)

+#define DEFAULT_MIGRATE_MULTIFD_THREADS 2
+
 static NotifierList migration_state_notifiers =
     NOTIFIER_LIST_INITIALIZER(migration_state_notifiers);

@@ -91,6 +93,8 @@ MigrationState *migrate_get_current(void)
                 DEFAULT_MIGRATE_X_CPU_THROTTLE_INITIAL,
         .parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT] =
                 DEFAULT_MIGRATE_X_CPU_THROTTLE_INCREMENT,
+        .parameters[MIGRATION_PARAMETER_X_MULTIFD_THREADS] =
+                DEFAULT_MIGRATE_MULTIFD_THREADS,
     };

     if (!once) {
@@ -521,6 +525,8 @@ MigrationParameters *qmp_query_migrate_parameters(Error **errp)
             s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INITIAL];
     params->x_cpu_throttle_increment =
             s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT];
+    params->x_multifd_threads =
+            s->parameters[MIGRATION_PARAMETER_X_MULTIFD_THREADS];

     return params;
 }
@@ -717,7 +723,10 @@ void qmp_migrate_set_parameters(bool has_compress_level,
                                 bool has_x_cpu_throttle_initial,
                                 int64_t x_cpu_throttle_initial,
                                 bool has_x_cpu_throttle_increment,
-                                int64_t x_cpu_throttle_increment, Error **errp)
+                                int64_t x_cpu_throttle_increment,
+                                bool has_multifd_threads,
+                                int64_t multifd_threads,
+                                Error **errp)
 {
     MigrationState *s = migrate_get_current();

@@ -753,6 +762,13 @@ void qmp_migrate_set_parameters(bool has_compress_level,
                    "an integer in the range of 1 to 99");
     }

+    if (has_multifd_threads &&
+            (multifd_threads < 1 || multifd_threads > 255)) {
+        error_setg(errp, QERR_INVALID_PARAMETER_VALUE,
+                   "multifd_threads",
+                   "is invalid, it should be in the range of 1 to 255");
+        return;
+    }
     if (has_compress_level) {
         s->parameters[MIGRATION_PARAMETER_COMPRESS_LEVEL] = compress_level;
     }
@@ -772,6 +788,9 @@ void qmp_migrate_set_parameters(bool has_compress_level,
         s->parameters[MIGRATION_PARAMETER_X_CPU_THROTTLE_INCREMENT] =
                                                     x_cpu_throttle_increment;
     }
+    if (has_multifd_threads) {
+        s->parameters[MIGRATION_PARAMETER_X_MULTIFD_THREADS] = multifd_threads;
+    }
 }

 void qmp_migrate_start_postcopy(Error **errp)
@@ -1196,6 +1215,15 @@ bool migrate_multifd(void)
     return s->enabled_capabilities[MIGRATION_CAPABILITY_X_MULTIFD];
 }

+int migrate_multifd_threads(void)
+{
+    MigrationState *s;
+
+    s = migrate_get_current();
+
+    return s->parameters[MIGRATION_PARAMETER_X_MULTIFD_THREADS];
+}
+
 int migrate_use_xbzrle(void)
 {
     MigrationState *s;
diff --git a/qapi-schema.json b/qapi-schema.json
index 9fdf902..6ff9ac6 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -613,11 +613,16 @@
 # @x-cpu-throttle-increment: throttle percentage increase each time
 #                            auto-converge detects that migration is not making
 #                            progress. The default value is 10. (Since 2.5)
+#
+# @x-multifd-threads: Number of threads used to migrate data in parallel
+#                     The default value is 1 (since 2.6)
+#
 # Since: 2.4
 ##
 { 'enum': 'MigrationParameter',
   'data': ['compress-level', 'compress-threads', 'decompress-threads',
-           'x-cpu-throttle-initial', 'x-cpu-throttle-increment'] }
+           'x-cpu-throttle-initial', 'x-cpu-throttle-increment',
+           'x-multifd-threads'] }

 #
 # @migrate-set-parameters
@@ -637,6 +642,10 @@
 # @x-cpu-throttle-increment: throttle percentage increase each time
 #                            auto-converge detects that migration is not making
 #                            progress. The default value is 10. (Since 2.5)
+#
+# @x-multifd-threads: Number of threads used to migrate data in parallel
+#                     The default value is 1 (since 2.6)
+#
 # Since: 2.4
 ##
 { 'command': 'migrate-set-parameters',
@@ -644,7 +653,8 @@
             '*compress-threads': 'int',
             '*decompress-threads': 'int',
             '*x-cpu-throttle-initial': 'int',
-            '*x-cpu-throttle-increment': 'int'} }
+            '*x-cpu-throttle-increment': 'int',
+            '*x-multifd-threads': 'int'} }

 #
 # @MigrationParameters
@@ -663,6 +673,8 @@
 #                            auto-converge detects that migration is not making
 #                            progress. The default value is 10. (Since 2.5)
 #
+# @x-multifd-threads: Number of threads used to migrate data in parallel
+#                     The default value is 1 (since 2.6)
 # Since: 2.4
 ##
 { 'struct': 'MigrationParameters',
@@ -670,7 +682,8 @@
             'compress-threads': 'int',
             'decompress-threads': 'int',
             'x-cpu-throttle-initial': 'int',
-            'x-cpu-throttle-increment': 'int'} }
+            'x-cpu-throttle-increment': 'int',
+            'x-multifd-threads': 'int'} }
 ##
 # @query-migrate-parameters
 #
-- 
2.5.5