From: Max Reitz <mreitz@redhat.com>
To: qemu-block@nongnu.org
Cc: Kevin Wolf <kwolf@redhat.com>,
Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>,
qemu-devel@nongnu.org, Max Reitz <mreitz@redhat.com>
Subject: [PATCH 6/7] iotests/129: Limit mirror job's buffer size
Date: Wed, 13 Jan 2021 15:06:15 +0100 [thread overview]
Message-ID: <20210113140616.150283-7-mreitz@redhat.com> (raw)
In-Reply-To: <20210113140616.150283-1-mreitz@redhat.com>
Issuing 'stop' on the VM drains all nodes. If the mirror job has many
large requests in flight, this may lead to significant I/O that looks a
bit like the job is being drained.
We can limit the I/O in flight by limiting the buffer size, so mirror
will make very little progress during the 'stop' drain.
(We do not need to do anything about commit, which has a buffer size of
512 kB by default; or backup, which goes cluster by cluster. Once we
have asynchronous requests for backup, that will change, but then we can
fine-tune the backup job to only perform a single request on a very
small chunk, too.)
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
tests/qemu-iotests/129 | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tests/qemu-iotests/129 b/tests/qemu-iotests/129
index e6753c90ef..c3ad584ba2 100755
--- a/tests/qemu-iotests/129
+++ b/tests/qemu-iotests/129
@@ -69,7 +69,7 @@ class TestStopWithBlockJob(iotests.QMPTestCase):
def test_drive_mirror(self):
self.do_test_stop("drive-mirror", device="drive0",
target=self.target_img, format=iotests.imgfmt,
- sync="full")
+ sync="full", buf_size=65536)
def test_drive_backup(self):
self.do_test_stop("drive-backup", device="drive0",
--
2.29.2
next prev parent reply other threads:[~2021-01-13 14:19 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-13 14:06 [PATCH 0/7] iotests/129: Fix it Max Reitz
2021-01-13 14:06 ` [PATCH 1/7] iotests: Move try_remove to iotests.py Max Reitz
2021-01-13 14:25 ` Eric Blake
2021-01-13 14:06 ` [PATCH 2/7] iotests/129: Remove test images in tearDown() Max Reitz
2021-01-13 14:34 ` Vladimir Sementsov-Ogievskiy
2021-01-13 14:43 ` Eric Blake
2021-01-13 14:06 ` [PATCH 3/7] iotests/129: Do not check @busy Max Reitz
2021-01-13 14:48 ` Eric Blake
2021-01-13 15:01 ` Vladimir Sementsov-Ogievskiy
2021-01-13 14:06 ` [PATCH 4/7] iotests/129: Use throttle node Max Reitz
2021-01-13 14:10 ` Max Reitz
2021-01-13 14:53 ` Eric Blake
2021-01-13 15:07 ` Vladimir Sementsov-Ogievskiy
2021-01-13 15:15 ` Max Reitz
2021-01-13 16:46 ` Vladimir Sementsov-Ogievskiy
2021-01-13 17:02 ` Max Reitz
2021-01-13 17:05 ` Vladimir Sementsov-Ogievskiy
2021-01-13 14:06 ` [PATCH 5/7] iotests/129: Actually test a commit job Max Reitz
2021-01-13 15:58 ` Eric Blake
2021-01-13 16:52 ` Vladimir Sementsov-Ogievskiy
2021-01-13 14:06 ` Max Reitz [this message]
2021-01-13 16:03 ` [PATCH 6/7] iotests/129: Limit mirror job's buffer size Eric Blake
2021-01-13 17:02 ` Vladimir Sementsov-Ogievskiy
2021-01-13 14:06 ` [PATCH 7/7] iotests/129: Clean up pylint and mypy complaints Max Reitz
2021-01-13 16:04 ` Eric Blake
2021-01-13 14:31 ` [PATCH 0/7] iotests/129: Fix it Vladimir Sementsov-Ogievskiy
2021-01-13 15:19 ` Max Reitz
2021-01-13 15:29 ` Vladimir Sementsov-Ogievskiy
2021-01-13 14:38 ` Kevin Wolf
2021-01-13 14:59 ` Vladimir Sementsov-Ogievskiy
2021-01-13 15:26 ` Max Reitz
2021-01-13 15:43 ` Kevin Wolf
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