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From: "Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>
To: qemu-devel@nongnu.org, quintela@redhat.com, peterx@redhat.com,
	thuth@redhat.com, lvivier@redhat.com
Cc: philmd@redhat.com
Subject: [PATCH] tests/migration: Add some slack to auto converge
Date: Mon, 10 Feb 2020 19:57:31 +0000	[thread overview]
Message-ID: <20200210195731.177595-1-dgilbert@redhat.com> (raw)

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

There's an assert in autoconverge that checks that we quit the
iteration when we go below the expected threshold.  Philippe
saw a case where this assert fired with the measured value
slightly over the threshold. (about 3k out of a few million).

I can think of two reasons:
  a) Rounding errors
  b) That after we make the decision to quit iteration we do one
    more sync and that sees a few more dirty pages.

So add 1% slack to the assertion, that should cover a and
most cases of b, probably all we'll see for the test.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 tests/qtest/migration-test.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tests/qtest/migration-test.c b/tests/qtest/migration-test.c
index cf27ebbc9d..a78ac0c7da 100644
--- a/tests/qtest/migration-test.c
+++ b/tests/qtest/migration-test.c
@@ -1237,7 +1237,8 @@ static void test_migrate_auto_converge(void)
     g_assert_cmpint(percentage, <=, max_pct);
 
     remaining = read_ram_property_int(from, "remaining");
-    g_assert_cmpint(remaining, <, expected_threshold);
+    g_assert_cmpint(remaining, <,
+                    (expected_threshold + expected_threshold / 100));
 
     migrate_continue(from, "pre-switchover");
 
-- 
2.24.1



             reply	other threads:[~2020-02-10 19:59 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-10 19:57 Dr. David Alan Gilbert (git) [this message]
2020-02-10 23:05 ` [PATCH] tests/migration: Add some slack to auto converge Peter Xu
2020-02-11  8:34 ` Juan Quintela

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