[RFC,v2,2/2] migration: Tally pre-copy, downtime and post-copy bytes independently

Commit Message

David Edmondson Dec. 20, 2021, 9:34 a.m. UTC

Provide information on the number of bytes copied in the pre-copy,
downtime and post-copy phases of migration.

Signed-off-by: David Edmondson <[e-mail]>
---
 migration/migration.c |  3 +++
 migration/ram.c       |  7 +++++++
 monitor/hmp-cmds.c    | 12 ++++++++++++
 qapi/migration.json   | 13 ++++++++++++-
 4 files changed, 34 insertions(+), 1 deletion(-)

Comments

Philippe Mathieu-Daudé Dec. 21, 2021, 8:28 a.m. UTC | #1

On 12/20/21 10:34, David Edmondson wrote:
> Provide information on the number of bytes copied in the pre-copy,
> downtime and post-copy phases of migration.
> 
> Signed-off-by: David Edmondson <[e-mail]>
> ---
>  migration/migration.c |  3 +++
>  migration/ram.c       |  7 +++++++
>  monitor/hmp-cmds.c    | 12 ++++++++++++
>  qapi/migration.json   | 13 ++++++++++++-
>  4 files changed, 34 insertions(+), 1 deletion(-)

Reviewed-by: Philippe Mathieu-Daudé <[e-mail]>

Patch

diff --git a/migration/migration.c b/migration/migration.c
index 3de11ae921..3950510be7 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1013,6 +1013,9 @@  static void populate_ram_info(MigrationInfo *info, MigrationState *s)
     info->ram->page_size = page_size;
     info->ram->multifd_bytes = ram_counters.multifd_bytes;
     info->ram->pages_per_second = s->pages_per_second;
+    info->ram->precopy_bytes = ram_counters.precopy_bytes;
+    info->ram->downtime_bytes = ram_counters.downtime_bytes;
+    info->ram->postcopy_bytes = ram_counters.postcopy_bytes;
 
     if (migrate_use_xbzrle()) {
         info->has_xbzrle_cache = true;
diff --git a/migration/ram.c b/migration/ram.c
index bd53e50a7f..389868c988 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -388,6 +388,13 @@  MigrationStats ram_counters;
 
 static void ram_transferred_add(uint64_t bytes)
 {
+    if (runstate_is_running()) {
+        ram_counters.precopy_bytes += bytes;
+    } else if (migration_in_postcopy()) {
+        ram_counters.postcopy_bytes += bytes;
+    } else {
+        ram_counters.downtime_bytes += bytes;
+    }
     ram_counters.transferred += bytes;
 }
 
diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
index 9c91bf93e9..6049772178 100644
--- a/monitor/hmp-cmds.c
+++ b/monitor/hmp-cmds.c
@@ -293,6 +293,18 @@  void hmp_info_migrate(Monitor *mon, const QDict *qdict)
             monitor_printf(mon, "postcopy request count: %" PRIu64 "\n",
                            info->ram->postcopy_requests);
         }
+        if (info->ram->precopy_bytes) {
+            monitor_printf(mon, "precopy ram: %" PRIu64 " kbytes\n",
+                           info->ram->precopy_bytes >> 10);
+        }
+        if (info->ram->downtime_bytes) {
+            monitor_printf(mon, "downtime ram: %" PRIu64 " kbytes\n",
+                           info->ram->downtime_bytes >> 10);
+        }
+        if (info->ram->postcopy_bytes) {
+            monitor_printf(mon, "postcopy ram: %" PRIu64 " kbytes\n",
+                           info->ram->postcopy_bytes >> 10);
+        }
     }
 
     if (info->has_disk) {
diff --git a/qapi/migration.json b/qapi/migration.json
index bbfd48cf0b..5975a0e104 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -46,6 +46,15 @@ 
 # @pages-per-second: the number of memory pages transferred per second
 #                    (Since 4.0)
 #
+# @precopy-bytes: The number of bytes sent in the pre-copy phase
+#                 (since 7.0).
+#
+# @downtime-bytes: The number of bytes sent while the guest is paused
+#                  (since 7.0).
+#
+# @postcopy-bytes: The number of bytes sent during the post-copy phase
+#                  (since 7.0).
+#
 # Since: 0.14
 ##
 { 'struct': 'MigrationStats',
@@ -54,7 +63,9 @@ 
            'normal-bytes': 'int', 'dirty-pages-rate' : 'int',
            'mbps' : 'number', 'dirty-sync-count' : 'int',
            'postcopy-requests' : 'int', 'page-size' : 'int',
-           'multifd-bytes' : 'uint64', 'pages-per-second' : 'uint64' } }
+           'multifd-bytes' : 'uint64', 'pages-per-second' : 'uint64',
+           'precopy-bytes' : 'uint64', 'downtime-bytes' : 'uint64',
+           'postcopy-bytes' : 'uint64' } }
 
 ##
 # @XBZRLECacheStats: