1#!/usr/bin/env python 2# 3# Tests for IO throttling 4# 5# Copyright (C) 2015 Red Hat, Inc. 6# Copyright (C) 2015-2016 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 24nsec_per_sec = 1000000000 25 26class ThrottleTestCase(iotests.QMPTestCase): 27 test_img = "null-aio://" 28 max_drives = 3 29 30 def blockstats(self, device): 31 result = self.vm.qmp("query-blockstats") 32 for r in result['return']: 33 if r['device'] == device: 34 stat = r['stats'] 35 return stat['rd_bytes'], stat['rd_operations'], stat['wr_bytes'], stat['wr_operations'] 36 raise Exception("Device not found for blockstats: %s" % device) 37 38 def setUp(self): 39 self.vm = iotests.VM() 40 for i in range(0, self.max_drives): 41 self.vm.add_drive(self.test_img) 42 self.vm.launch() 43 44 def tearDown(self): 45 self.vm.shutdown() 46 47 def configure_throttle(self, ndrives, params): 48 params['group'] = 'test' 49 50 # Set the I/O throttling parameters to all drives 51 for i in range(0, ndrives): 52 params['device'] = 'drive%d' % i 53 result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params) 54 self.assert_qmp(result, 'return', {}) 55 56 def do_test_throttle(self, ndrives, seconds, params): 57 def check_limit(limit, num): 58 # IO throttling algorithm is discrete, allow 10% error so the test 59 # is more robust 60 return limit == 0 or \ 61 (num < seconds * limit * 1.1 / ndrives 62 and num > seconds * limit * 0.9 / ndrives) 63 64 # Set vm clock to a known value 65 ns = seconds * nsec_per_sec 66 self.vm.qtest("clock_step %d" % ns) 67 68 # Submit enough requests so the throttling mechanism kicks 69 # in. The throttled requests won't be executed until we 70 # advance the virtual clock. 71 rq_size = 512 72 rd_nr = max(params['bps'] / rq_size / 2, 73 params['bps_rd'] / rq_size, 74 params['iops'] / 2, 75 params['iops_rd']) 76 rd_nr *= seconds * 2 77 rd_nr /= ndrives 78 wr_nr = max(params['bps'] / rq_size / 2, 79 params['bps_wr'] / rq_size, 80 params['iops'] / 2, 81 params['iops_wr']) 82 wr_nr *= seconds * 2 83 wr_nr /= ndrives 84 85 # Send I/O requests to all drives 86 for i in range(rd_nr): 87 for drive in range(0, ndrives): 88 self.vm.hmp_qemu_io("drive%d" % drive, "aio_read %d %d" % 89 (i * rq_size, rq_size)) 90 91 for i in range(wr_nr): 92 for drive in range(0, ndrives): 93 self.vm.hmp_qemu_io("drive%d" % drive, "aio_write %d %d" % 94 (i * rq_size, rq_size)) 95 96 # We'll store the I/O stats for each drive in these arrays 97 start_rd_bytes = [0] * ndrives 98 start_rd_iops = [0] * ndrives 99 start_wr_bytes = [0] * ndrives 100 start_wr_iops = [0] * ndrives 101 end_rd_bytes = [0] * ndrives 102 end_rd_iops = [0] * ndrives 103 end_wr_bytes = [0] * ndrives 104 end_wr_iops = [0] * ndrives 105 106 # Read the stats before advancing the clock 107 for i in range(0, ndrives): 108 start_rd_bytes[i], start_rd_iops[i], start_wr_bytes[i], \ 109 start_wr_iops[i] = self.blockstats('drive%d' % i) 110 111 self.vm.qtest("clock_step %d" % ns) 112 113 # Read the stats after advancing the clock 114 for i in range(0, ndrives): 115 end_rd_bytes[i], end_rd_iops[i], end_wr_bytes[i], \ 116 end_wr_iops[i] = self.blockstats('drive%d' % i) 117 118 # Check that the I/O is within the limits and evenly distributed 119 for i in range(0, ndrives): 120 rd_bytes = end_rd_bytes[i] - start_rd_bytes[i] 121 rd_iops = end_rd_iops[i] - start_rd_iops[i] 122 wr_bytes = end_wr_bytes[i] - start_wr_bytes[i] 123 wr_iops = end_wr_iops[i] - start_wr_iops[i] 124 125 self.assertTrue(check_limit(params['bps'], rd_bytes + wr_bytes)) 126 self.assertTrue(check_limit(params['bps_rd'], rd_bytes)) 127 self.assertTrue(check_limit(params['bps_wr'], wr_bytes)) 128 self.assertTrue(check_limit(params['iops'], rd_iops + wr_iops)) 129 self.assertTrue(check_limit(params['iops_rd'], rd_iops)) 130 self.assertTrue(check_limit(params['iops_wr'], wr_iops)) 131 132 def test_all(self): 133 params = {"bps": 4096, 134 "bps_rd": 4096, 135 "bps_wr": 4096, 136 "iops": 10, 137 "iops_rd": 10, 138 "iops_wr": 10, 139 } 140 # Repeat the test with different numbers of drives 141 for ndrives in range(1, self.max_drives + 1): 142 # Pick each out of all possible params and test 143 for tk in params: 144 limits = dict([(k, 0) for k in params]) 145 limits[tk] = params[tk] * ndrives 146 self.configure_throttle(ndrives, limits) 147 self.do_test_throttle(ndrives, 5, limits) 148 149 def test_burst(self): 150 params = {"bps": 4096, 151 "bps_rd": 4096, 152 "bps_wr": 4096, 153 "iops": 10, 154 "iops_rd": 10, 155 "iops_wr": 10, 156 } 157 ndrives = 1 158 # Pick each out of all possible params and test 159 for tk in params: 160 rate = params[tk] * ndrives 161 burst_rate = rate * 7 162 burst_length = 4 163 164 # Configure the throttling settings 165 settings = dict([(k, 0) for k in params]) 166 settings[tk] = rate 167 settings['%s_max' % tk] = burst_rate 168 settings['%s_max_length' % tk] = burst_length 169 self.configure_throttle(ndrives, settings) 170 171 # Wait for the bucket to empty so we can do bursts 172 wait_ns = nsec_per_sec * burst_length * burst_rate / rate 173 self.vm.qtest("clock_step %d" % wait_ns) 174 175 # Test I/O at the max burst rate 176 limits = dict([(k, 0) for k in params]) 177 limits[tk] = burst_rate 178 self.do_test_throttle(ndrives, burst_length, limits) 179 180 # Now test I/O at the normal rate 181 limits[tk] = rate 182 self.do_test_throttle(ndrives, 5, limits) 183 184class ThrottleTestCoroutine(ThrottleTestCase): 185 test_img = "null-co://" 186 187if __name__ == '__main__': 188 iotests.main(supported_fmts=["raw"]) 189