Re: [Qemu-devel] [PATCH 4/4] qemu-iotests: Add 080 for IO throttling

["Benoît Canet" <benoit.canet@irqsave.net>]

Le Wednesday 29 Jan 2014 à 16:40:43 (+0800), Fam Zheng a écrit :
> This case utilizes qemu-io command "aio_{read,write} -a -q" to verify
> the effectiveness of IO throttling options.
> 
> The "-a" option will cause qemu-io requests to be accounted.
> 
> It's implemented by driving the vm timer from qtest protocol, so the
> throttling timers are signaled with determinied 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     | 164 +++++++++++++++++++++++++++++++++++++++++++++
>  tests/qemu-iotests/080.out |   5 ++
>  tests/qemu-iotests/group   |   1 +
>  3 files changed, 170 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..222bb37
> --- /dev/null
> +++ b/tests/qemu-iotests/080
> @@ -0,0 +1,164 @@
> +#!/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):
> +    image_len = 80 * 1024 * 1024 # MB
> +
> +    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, "bps=1024,bps_max=1")
> +        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=10, **limits):
> +        def check_limit(limit, num):
> +            # IO throttling algorithm is discrete, allow 10% error so the test
> +            # is more deterministic
> +            return limit == 0 or num < seconds * limit * 1.1
> +
> +        nsec_per_sec = 1000000000
> +
> +        limits['bps_max'] = 1
> +        limits['iops_max'] = 1
> +
> +        # Enqueue many requests to throttling queue
> +        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_cmd("clock_step %d" % ns)
> +
> +        # Append many requests into the throttle queue
> +        # They drain bps_max and iops_max
> +        # The rest requests won't get executed until qtest clock is driven
> +        for i in range(1000):
> +            self.vm.hmp_qemu_io("drive0", "aio_read -a -q 0 512")
> +            self.vm.hmp_qemu_io("drive0", "aio_write -a -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_cmd("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')
> +
> +        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)
> +        assert check_limit(limits['bps_rd'], rd_bytes)
> +        assert check_limit(limits['bps'], wr_bytes)
> +        assert check_limit(limits['bps_wr'], wr_bytes)
> +        assert check_limit(limits['iops'], rd_iops)
> +        assert check_limit(limits['iops_rd'], rd_iops)
> +        assert check_limit(limits['iops'], wr_iops)
> +        assert check_limit(limits['iops_wr'], wr_iops)
> +
> +    def test_bps(self):
> +        self.do_test_throttle(**{
> +            'device': 'drive0',
> +            'bps': 1000,
> +            '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': 1000,
> +            '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': 1000,
> +            '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
> -- 
> 1.8.5.3
> 
> 

I like the way it's done.
Reviewed-by: Benoit Canet <benoit@irqsave.net>