[Qemu-devel] [PULL 5/8] Postcopy: Add stats on page requests

[Amit Shah <amit.shah@redhat.com>]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

On the source, add a count of page requests received from the
destination.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Message-Id: <1465555776-23286-4-git-send-email-dgilbert@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>
---
 hmp.c                         | 4 ++++
 include/migration/migration.h | 2 ++
 migration/migration.c         | 2 ++
 migration/ram.c               | 1 +
 qapi-schema.json              | 6 +++++-
 5 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/hmp.c b/hmp.c
index a4b1d3d..4b8e987 100644
--- a/hmp.c
+++ b/hmp.c
@@ -217,6 +217,10 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
             monitor_printf(mon, "dirty pages rate: %" PRIu64 " pages\n",
                            info->ram->dirty_pages_rate);
         }
+        if (info->ram->postcopy_requests) {
+            monitor_printf(mon, "postcopy request count: %" PRIu64 "\n",
+                           info->ram->postcopy_requests);
+        }
     }
 
     if (info->has_disk) {
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 8aa9860..3c96623 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -160,6 +160,8 @@ struct MigrationState
     int64_t xbzrle_cache_size;
     int64_t setup_time;
     int64_t dirty_sync_count;
+    /* Count of requests incoming from destination */
+    int64_t postcopy_requests;
 
     /* Flag set once the migration has been asked to enter postcopy */
     bool start_postcopy;
diff --git a/migration/migration.c b/migration/migration.c
index 5251cf5..213580d 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -614,6 +614,7 @@ static void populate_ram_info(MigrationInfo *info, MigrationState *s)
     info->ram->normal_bytes = norm_mig_bytes_transferred();
     info->ram->mbps = s->mbps;
     info->ram->dirty_sync_count = s->dirty_sync_count;
+    info->ram->postcopy_requests = s->postcopy_requests;
 
     if (s->state != MIGRATION_STATUS_COMPLETED) {
         info->ram->remaining = ram_bytes_remaining();
@@ -991,6 +992,7 @@ MigrationState *migrate_init(const MigrationParams *params)
     s->dirty_sync_count = 0;
     s->start_postcopy = false;
     s->postcopy_after_devices = false;
+    s->postcopy_requests = 0;
     s->migration_thread_running = false;
     s->last_req_rb = NULL;
     error_free(s->error);
diff --git a/migration/ram.c b/migration/ram.c
index 5f929d6..42fb8ac 100644
--- a/migration/ram.c
+++ b/migration/ram.c
@@ -1169,6 +1169,7 @@ int ram_save_queue_pages(MigrationState *ms, const char *rbname,
 {
     RAMBlock *ramblock;
 
+    ms->postcopy_requests++;
     rcu_read_lock();
     if (!rbname) {
         /* Reuse last RAMBlock */
diff --git a/qapi-schema.json b/qapi-schema.json
index 5c7b87c..ab2c577 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -382,13 +382,17 @@
 #
 # @dirty-sync-count: number of times that dirty ram was synchronized (since 2.1)
 #
+# @postcopy-requests: The number of page requests received from the destination
+#        (since 2.7)
+#
 # Since: 0.14.0
 ##
 { 'struct': 'MigrationStats',
   'data': {'transferred': 'int', 'remaining': 'int', 'total': 'int' ,
            'duplicate': 'int', 'skipped': 'int', 'normal': 'int',
            'normal-bytes': 'int', 'dirty-pages-rate' : 'int',
-           'mbps' : 'number', 'dirty-sync-count' : 'int' } }
+           'mbps' : 'number', 'dirty-sync-count' : 'int',
+           'postcopy-requests' : 'int' } }
 
 ##
 # @XBZRLECacheStats
-- 
2.7.4