xref: /openbmc/qemu/tests/qemu-iotests/093 (revision 585ec727)
1#!/usr/bin/env python
2#
3# Tests for IO throttling
4#
5# Copyright (C) 2015 Red Hat, Inc.
6# Copyright (C) 2015 Igalia, S.L.
7#
8# This program is free software; you can redistribute it and/or modify
9# it under the terms of the GNU General Public License as published by
10# the Free Software Foundation; either version 2 of the License, or
11# (at your option) any later version.
12#
13# This program is distributed in the hope that it will be useful,
14# but WITHOUT ANY WARRANTY; without even the implied warranty of
15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16# GNU General Public License for more details.
17#
18# You should have received a copy of the GNU General Public License
19# along with this program.  If not, see <http://www.gnu.org/licenses/>.
20#
21
22import iotests
23
24class ThrottleTestCase(iotests.QMPTestCase):
25    test_img = "null-aio://"
26    max_drives = 3
27
28    def blockstats(self, device):
29        result = self.vm.qmp("query-blockstats")
30        for r in result['return']:
31            if r['device'] == device:
32                stat = r['stats']
33                return stat['rd_bytes'], stat['rd_operations'], stat['wr_bytes'], stat['wr_operations']
34        raise Exception("Device not found for blockstats: %s" % device)
35
36    def setUp(self):
37        self.vm = iotests.VM()
38        for i in range(0, self.max_drives):
39            self.vm.add_drive(self.test_img)
40        self.vm.launch()
41
42    def tearDown(self):
43        self.vm.shutdown()
44
45    def do_test_throttle(self, ndrives, seconds, params):
46        def check_limit(limit, num):
47            # IO throttling algorithm is discrete, allow 10% error so the test
48            # is more robust
49            return limit == 0 or \
50                   (num < seconds * limit * 1.1 / ndrives
51                   and num > seconds * limit * 0.9 / ndrives)
52
53        nsec_per_sec = 1000000000
54
55        params['group'] = 'test'
56
57        # Set the I/O throttling parameters to all drives
58        for i in range(0, ndrives):
59            params['device'] = 'drive%d' % i
60            result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params)
61            self.assert_qmp(result, 'return', {})
62
63        # Set vm clock to a known value
64        ns = seconds * nsec_per_sec
65        self.vm.qtest("clock_step %d" % ns)
66
67        # Submit enough requests. They will drain bps_max and iops_max, but the
68        # rest requests won't get executed until we advance the virtual clock
69        # with qtest interface
70        rq_size = 512
71        rd_nr = max(params['bps'] / rq_size / 2,
72                    params['bps_rd'] / rq_size,
73                    params['iops'] / 2,
74                    params['iops_rd'])
75        rd_nr *= seconds * 2
76        rd_nr /= ndrives
77        wr_nr = max(params['bps'] / rq_size / 2,
78                    params['bps_wr'] / rq_size,
79                    params['iops'] / 2,
80                    params['iops_wr'])
81        wr_nr *= seconds * 2
82        wr_nr /= ndrives
83
84        # Send I/O requests to all drives
85        for i in range(rd_nr):
86            for drive in range(0, ndrives):
87                self.vm.hmp_qemu_io("drive%d" % drive, "aio_read %d %d" %
88                                    (i * rq_size, rq_size))
89
90        for i in range(wr_nr):
91            for drive in range(0, ndrives):
92                self.vm.hmp_qemu_io("drive%d" % drive, "aio_write %d %d" %
93                                    (i * rq_size, rq_size))
94
95        # We'll store the I/O stats for each drive in these arrays
96        start_rd_bytes = [0] * ndrives
97        start_rd_iops  = [0] * ndrives
98        start_wr_bytes = [0] * ndrives
99        start_wr_iops  = [0] * ndrives
100        end_rd_bytes   = [0] * ndrives
101        end_rd_iops    = [0] * ndrives
102        end_wr_bytes   = [0] * ndrives
103        end_wr_iops    = [0] * ndrives
104
105        # Read the stats before advancing the clock
106        for i in range(0, ndrives):
107            start_rd_bytes[i], start_rd_iops[i], start_wr_bytes[i], \
108                start_wr_iops[i] = self.blockstats('drive%d' % i)
109
110        self.vm.qtest("clock_step %d" % ns)
111
112        # Read the stats after advancing the clock
113        for i in range(0, ndrives):
114            end_rd_bytes[i], end_rd_iops[i], end_wr_bytes[i], \
115                end_wr_iops[i] = self.blockstats('drive%d' % i)
116
117        # Check that the I/O is within the limits and evenly distributed
118        for i in range(0, ndrives):
119            rd_bytes = end_rd_bytes[i] - start_rd_bytes[i]
120            rd_iops = end_rd_iops[i] - start_rd_iops[i]
121            wr_bytes = end_wr_bytes[i] - start_wr_bytes[i]
122            wr_iops = end_wr_iops[i] - start_wr_iops[i]
123
124            self.assertTrue(check_limit(params['bps'], rd_bytes + wr_bytes))
125            self.assertTrue(check_limit(params['bps_rd'], rd_bytes))
126            self.assertTrue(check_limit(params['bps_wr'], wr_bytes))
127            self.assertTrue(check_limit(params['iops'], rd_iops + wr_iops))
128            self.assertTrue(check_limit(params['iops_rd'], rd_iops))
129            self.assertTrue(check_limit(params['iops_wr'], wr_iops))
130
131    def test_all(self):
132        params = {"bps": 4096,
133                  "bps_rd": 4096,
134                  "bps_wr": 4096,
135                  "iops": 10,
136                  "iops_rd": 10,
137                  "iops_wr": 10,
138                 }
139        # Repeat the test with different numbers of drives
140        for ndrives in range(1, self.max_drives + 1):
141            # Pick each out of all possible params and test
142            for tk in params:
143                limits = dict([(k, 0) for k in params])
144                limits[tk] = params[tk] * ndrives
145                self.do_test_throttle(ndrives, 5, limits)
146
147class ThrottleTestCoroutine(ThrottleTestCase):
148    test_img = "null-co://"
149
150if __name__ == '__main__':
151    iotests.main(supported_fmts=["raw"])
152