From ddf2d98a94c8a98a661a217fb629cfd15f4dcec7 Mon Sep 17 00:00:00 2001 From: Stefan Hajnoczi Date: Tue, 8 May 2018 14:54:35 +0100 Subject: [PATCH] qemu-iotests: reduce chance of races in 185 Commit 8565c3ab537e78f3e69977ec2c609dc9417a806e ("qemu-iotests: fix 185") identified a race condition in a sub-test. Similar issues also affect the other sub-tests. If disk I/O completes quickly, it races with the QMP 'quit' command. This causes spurious test failures because QMP events are emitted in an unpredictable order. This test relies on QEMU internals and there is no QMP API for getting deterministic behavior needed to make this test 100% reliable. At the same time, the test is useful and it would be a shame to remove it. Add sleep 0.5 to reduce the chance of races. This is not a real fix but appears to reduce spurious failures in practice. Cc: Vladimir Sementsov-Ogievskiy Signed-off-by: Stefan Hajnoczi Reviewed-by: Eric Blake Message-id: 20180508135436.30140-2-stefanha@redhat.com Reviewed-by: Jeff Cody Signed-off-by: Jeff Cody --- tests/qemu-iotests/185 | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/tests/qemu-iotests/185 b/tests/qemu-iotests/185 index 298d88d04e..975404c99d 100755 --- a/tests/qemu-iotests/185 +++ b/tests/qemu-iotests/185 @@ -118,6 +118,9 @@ _send_qemu_cmd $h \ 'speed': 65536 } }" \ "return" +# If we don't sleep here 'quit' command races with disk I/O +sleep 0.5 + _send_qemu_cmd $h "{ 'execute': 'quit' }" "return" wait=1 _cleanup_qemu @@ -137,6 +140,9 @@ _send_qemu_cmd $h \ 'speed': 65536 } }" \ "return" +# If we don't sleep here 'quit' command races with disk I/O +sleep 0.5 + _send_qemu_cmd $h "{ 'execute': 'quit' }" "return" wait=1 _cleanup_qemu @@ -183,6 +189,9 @@ _send_qemu_cmd $h \ 'speed': 65536 } }" \ "return" +# If we don't sleep here 'quit' command races with disk I/O +sleep 0.5 + _send_qemu_cmd $h "{ 'execute': 'quit' }" "return" wait=1 _cleanup_qemu @@ -201,6 +210,9 @@ _send_qemu_cmd $h \ 'speed': 65536 } }" \ "return" +# If we don't sleep here 'quit' command races with disk I/O +sleep 0.5 + _send_qemu_cmd $h "{ 'execute': 'quit' }" "return" wait=1 _cleanup_qemu