[PATCH v4 6/6] tests/migration: Add case for periodic ramblock dirty sync

[yong.huang@smartx.com]

From: Hyman Huang <yong.huang@smartx.com>

Signed-off-by: Hyman Huang <yong.huang@smartx.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
---
 tests/qtest/migration-test.c | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index 95e45b5029..e6a2803e71 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -2791,6 +2791,8 @@ static void test_migrate_auto_converge(void)
      * so we need to decrease a bandwidth.
      */
     const int64_t init_pct = 5, inc_pct = 25, max_pct = 95;
+    uint64_t prev_dirty_sync_cnt, dirty_sync_cnt;
+    int max_try_count, hit = 0;
 
     if (test_migrate_start(&from, &to, uri, &args)) {
         return;
@@ -2827,6 +2829,36 @@ static void test_migrate_auto_converge(void)
     } while (true);
     /* The first percentage of throttling should be at least init_pct */
     g_assert_cmpint(percentage, >=, init_pct);
+
+    /*
+     * End the loop when the dirty sync count greater than 1.
+     */
+    while ((dirty_sync_cnt = get_migration_pass(from)) < 2) {
+        usleep(1000 * 1000);
+    }
+
+    prev_dirty_sync_cnt = dirty_sync_cnt;
+
+    /*
+     * The RAMBlock dirty sync count must changes in 5 seconds, here we set
+     * the timeout to 10 seconds to ensure it changes.
+     *
+     * Note that migrate_ensure_non_converge set the max-bandwidth to 3MB/s,
+     * while the qtest mem is >= 100MB, one iteration takes at least 33s (100/3)
+     * to complete; this ensures that the RAMBlock dirty sync occurs.
+     */
+    max_try_count = 10;
+    while (--max_try_count) {
+        dirty_sync_cnt = get_migration_pass(from);
+        if (dirty_sync_cnt != prev_dirty_sync_cnt) {
+            hit = 1;
+            break;
+        }
+        prev_dirty_sync_cnt = dirty_sync_cnt;
+        sleep(1);
+    }
+    g_assert_cmpint(hit, ==, 1);
+
     /* Now, when we tested that throttling works, let it converge */
     migrate_ensure_converge(from);
 
-- 
2.27.0