[v3,5/5] qemu-iotests: Add 080 for IO throttling

This case utilizes qemu-io command "aio_{read,write} -q" to verify the
effectiveness of IO throttling options.

It's implemented by driving the vm timer from qtest protocol, so the
throttling timers are signaled with determined time duration. Then we
verify the completed IO requests are within 110% of bps and iops limits.

Signed-off-by: Fam Zheng <famz@redhat.com>
---
 tests/qemu-iotests/080     | 175 +++++++++++++++++++++++++++++++++++++++++++++
 tests/qemu-iotests/080.out |   5 ++
 tests/qemu-iotests/group   |   1 +
 3 files changed, 181 insertions(+)
 create mode 100755 tests/qemu-iotests/080
 create mode 100644 tests/qemu-iotests/080.out

The Tuesday 11 Feb 2014 à 14:41:02 (+0800), Fam Zheng wrote :
> This case utilizes qemu-io command "aio_{read,write} -q" to verify the
> effectiveness of IO throttling options.
> 
> It's implemented by driving the vm timer from qtest protocol, so the
> throttling timers are signaled with determined time duration. Then we
> verify the completed IO requests are within 110% of bps and iops limits.
> 
> Signed-off-by: Fam Zheng <famz@redhat.com>
> ---
>  tests/qemu-iotests/080     | 175 +++++++++++++++++++++++++++++++++++++++++++++
>  tests/qemu-iotests/080.out |   5 ++
>  tests/qemu-iotests/group   |   1 +
>  3 files changed, 181 insertions(+)
>  create mode 100755 tests/qemu-iotests/080
>  create mode 100644 tests/qemu-iotests/080.out
> 
> diff --git a/tests/qemu-iotests/080 b/tests/qemu-iotests/080
> new file mode 100755
> index 0000000..9e2c762
> --- /dev/null
> +++ b/tests/qemu-iotests/080
> @@ -0,0 +1,175 @@
> +#!/usr/bin/env python
> +#
> +# Tests for IO throttling
> +#
> +# Copyright (C) 2014 Red Hat, Inc.
> +#
> +# This program is free software; you can redistribute it and/or modify
> +# it under the terms of the GNU General Public License as published by
> +# the Free Software Foundation; either version 2 of the License, or
> +# (at your option) any later version.
> +#
> +# This program is distributed in the hope that it will be useful,
> +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> +# GNU General Public License for more details.
> +#
> +# You should have received a copy of the GNU General Public License
> +# along with this program.  If not, see <http://www.gnu.org/licenses/>.
> +#
> +
> +import time
> +import os
> +import iotests
> +from iotests import qemu_img
> +
> +test_img = os.path.join(iotests.test_dir, 'test.img')
> +
> +class ThrottleTestCase(iotests.QMPTestCase):
> +
> +    def blockstats(self, device):
> +        result = self.vm.qmp("query-blockstats")
> +        for r in result['return']:
> +            if r['device'] == device:
> +                stat = r['stats']
> +                return stat['rd_bytes'], stat['rd_operations'], stat['wr_bytes'], stat['wr_operations']
> +        raise Exception("Device not found for blockstats: %s" % device)
> +
> +    def setUp(self):
> +        qemu_img('create', '-f', iotests.imgfmt, test_img, "1G")
> +        self.vm = iotests.VM().add_drive(test_img)
> +        self.vm.launch()
> +
> +    def tearDown(self):
> +        self.vm.shutdown()
> +        os.remove(test_img)
> +
> +    def do_test_throttle(self, seconds=20, **limits):
> +        def check_limit(limit, num):
> +            # IO throttling algorithm is discrete, allow 10% error so the test
> +            # is more deterministic
> +            v = limit * seconds
> +            return limit == 0 or v * 0.9 <= num <= v * 1.1
> +
> +        nsec_per_sec = 1000000000
> +
> +        # With current interface we can't set burst to 0, they will be override
> +        # to bps / 10 and iops / 10. Setting to 1 workarounds this and gets to
> +        # a close effect as no burst, which is good enough for us
> +        limits['bps_max'] = 1
> +        limits['iops_max'] = 1
> +
> +        result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **limits)
> +        self.assert_qmp(result, 'return', {})
> +
> +        # Set vm clock to a known value
> +        ns = nsec_per_sec
> +        self.vm.qtest("clock_step %d" % ns)
> +
> +        # Append more than needed requests into the throttle queue, they should
> +        # drain bps_max and iops_max.
> +        # The remaining requests won't get executed until qtest clock is driven
> +        n = max(limits['iops'],
> +                limits['iops_rd'],
> +                limits['iops_wr'],
> +                limits['bps'] / 512,
> +                limits['bps_rd'] / 512,
> +                limits['bps_wr'] / 512) * seconds + 100
> +        for i in range(n):
> +            self.vm.hmp_qemu_io("drive0", "aio_read -q 0 512")
> +            self.vm.hmp_qemu_io("drive0", "aio_write -q 0 512")
> +
> +        start_rd_bytes, start_rd_iops, start_wr_bytes, start_wr_iops = self.blockstats('drive0')
> +
> +        ns += seconds * nsec_per_sec
> +        self.vm.qtest("clock_step %d" % ns)
> +        # wait for a while to let requests take off
> +        time.sleep(1)
> +        end_rd_bytes, end_rd_iops, end_wr_bytes, end_wr_iops = self.blockstats('drive0')
> +
> +        # Read and write requests should be processed
> +        assert end_rd_bytes > 0
> +        assert end_rd_iops > 0
> +        assert end_wr_bytes > 0
> +        assert end_wr_iops > 0
> +
> +        rd_bytes = end_rd_bytes - start_rd_bytes
> +        rd_iops = end_rd_iops - start_rd_iops
> +        wr_bytes = end_wr_bytes - start_wr_bytes
> +        wr_iops = end_wr_iops - start_wr_iops
> +
> +        assert check_limit(limits['bps'], rd_bytes + wr_bytes)
> +        assert check_limit(limits['bps_rd'], rd_bytes)
> +        assert check_limit(limits['bps_wr'], wr_bytes)
> +        assert check_limit(limits['iops'], rd_iops + wr_iops)
> +        assert check_limit(limits['iops_rd'], rd_iops)
> +        assert check_limit(limits['iops_wr'], wr_iops)
> +
> +    def test_bps(self):
> +        self.do_test_throttle(**{
> +            'device': 'drive0',
> +            'bps': 1024,
> +            'bps_rd': 0,
> +            'bps_wr': 0,
> +            'iops': 0,
> +            'iops_rd': 0,
> +            'iops_wr': 0,
> +            })
> +
> +    def test_bps_rd(self):
> +        self.do_test_throttle(**{
> +            'device': 'drive0',
> +            'bps': 0,
> +            'bps_rd': 1024,
> +            'bps_wr': 0,
> +            'iops': 0,
> +            'iops_rd': 0,
> +            'iops_wr': 0,
> +            })
> +
> +    def test_bps_wr(self):
> +        self.do_test_throttle(**{
> +            'device': 'drive0',
> +            'bps': 0,
> +            'bps_rd': 0,
> +            'bps_wr': 1024,
> +            'iops': 0,
> +            'iops_rd': 0,
> +            'iops_wr': 0,
> +            })
> +
> +    def test_iops(self):
> +        self.do_test_throttle(**{
> +            'device': 'drive0',
> +            'bps': 0,
> +            'bps_rd': 0,
> +            'bps_wr': 0,
> +            'iops': 10,
> +            'iops_rd': 0,
> +            'iops_wr': 0,
> +            })
> +
> +    def test_iops_rd(self):
> +        self.do_test_throttle(**{
> +            'device': 'drive0',
> +            'bps': 0,
> +            'bps_rd': 0,
> +            'bps_wr': 0,
> +            'iops': 0,
> +            'iops_rd': 10,
> +            'iops_wr': 0,
> +            })
> +
> +    def test_iops_wr(self):
> +        self.do_test_throttle(**{
> +            'device': 'drive0',
> +            'bps': 0,
> +            'bps_rd': 0,
> +            'bps_wr': 0,
> +            'iops': 0,
> +            'iops_rd': 0,
> +            'iops_wr': 10,
> +            })
> +
> +if __name__ == '__main__':
> +    iotests.main()
> diff --git a/tests/qemu-iotests/080.out b/tests/qemu-iotests/080.out
> new file mode 100644
> index 0000000..3f8a935
> --- /dev/null
> +++ b/tests/qemu-iotests/080.out
> @@ -0,0 +1,5 @@
> +......
> +----------------------------------------------------------------------
> +Ran 6 tests
> +
> +OK
> diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
> index 03c762f..013a7ef 100644
> --- a/tests/qemu-iotests/group
> +++ b/tests/qemu-iotests/group
> @@ -82,3 +82,4 @@
>  073 rw auto
>  074 rw auto
>  077 rw auto
> +080 rw auto
> -- 
> 1.8.5.4
> 
Reviewed-by: Benoit Canet <benoit@irqsave.net>