1#!/usr/bin/env python 2# 3# Tests for IO throttling 4# 5# Copyright (C) 2015 Red Hat, Inc. 6# 7# This program is free software; you can redistribute it and/or modify 8# it under the terms of the GNU General Public License as published by 9# the Free Software Foundation; either version 2 of the License, or 10# (at your option) any later version. 11# 12# This program is distributed in the hope that it will be useful, 13# but WITHOUT ANY WARRANTY; without even the implied warranty of 14# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15# GNU General Public License for more details. 16# 17# You should have received a copy of the GNU General Public License 18# along with this program. If not, see <http://www.gnu.org/licenses/>. 19# 20 21import iotests 22 23class ThrottleTestCase(iotests.QMPTestCase): 24 test_img = "null-aio://" 25 26 def blockstats(self, device): 27 result = self.vm.qmp("query-blockstats") 28 for r in result['return']: 29 if r['device'] == device: 30 stat = r['stats'] 31 return stat['rd_bytes'], stat['rd_operations'], stat['wr_bytes'], stat['wr_operations'] 32 raise Exception("Device not found for blockstats: %s" % device) 33 34 def setUp(self): 35 self.vm = iotests.VM().add_drive(self.test_img) 36 self.vm.launch() 37 38 def tearDown(self): 39 self.vm.shutdown() 40 41 def do_test_throttle(self, seconds, params): 42 def check_limit(limit, num): 43 # IO throttling algorithm is discrete, allow 10% error so the test 44 # is more robust 45 return limit == 0 or \ 46 (num < seconds * limit * 1.1 47 and num > seconds * limit * 0.9) 48 49 nsec_per_sec = 1000000000 50 51 params['device'] = 'drive0' 52 53 result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params) 54 self.assert_qmp(result, 'return', {}) 55 56 # Set vm clock to a known value 57 ns = seconds * nsec_per_sec 58 self.vm.qtest("clock_step %d" % ns) 59 60 # Submit enough requests. They will drain bps_max and iops_max, but the 61 # rest requests won't get executed until we advance the virtual clock 62 # with qtest interface 63 rq_size = 512 64 rd_nr = max(params['bps'] / rq_size / 2, 65 params['bps_rd'] / rq_size, 66 params['iops'] / 2, 67 params['iops_rd']) 68 rd_nr *= seconds * 2 69 wr_nr = max(params['bps'] / rq_size / 2, 70 params['bps_wr'] / rq_size, 71 params['iops'] / 2, 72 params['iops_wr']) 73 wr_nr *= seconds * 2 74 for i in range(rd_nr): 75 self.vm.hmp_qemu_io("drive0", "aio_read %d %d" % (i * rq_size, rq_size)) 76 for i in range(wr_nr): 77 self.vm.hmp_qemu_io("drive0", "aio_write %d %d" % (i * rq_size, rq_size)) 78 79 start_rd_bytes, start_rd_iops, start_wr_bytes, start_wr_iops = self.blockstats('drive0') 80 81 self.vm.qtest("clock_step %d" % ns) 82 end_rd_bytes, end_rd_iops, end_wr_bytes, end_wr_iops = self.blockstats('drive0') 83 84 rd_bytes = end_rd_bytes - start_rd_bytes 85 rd_iops = end_rd_iops - start_rd_iops 86 wr_bytes = end_wr_bytes - start_wr_bytes 87 wr_iops = end_wr_iops - start_wr_iops 88 89 self.assertTrue(check_limit(params['bps'], rd_bytes + wr_bytes)) 90 self.assertTrue(check_limit(params['bps_rd'], rd_bytes)) 91 self.assertTrue(check_limit(params['bps_wr'], wr_bytes)) 92 self.assertTrue(check_limit(params['iops'], rd_iops + wr_iops)) 93 self.assertTrue(check_limit(params['iops_rd'], rd_iops)) 94 self.assertTrue(check_limit(params['iops_wr'], wr_iops)) 95 96 def test_all(self): 97 params = {"bps": 4096, 98 "bps_rd": 4096, 99 "bps_wr": 4096, 100 "iops": 10, 101 "iops_rd": 10, 102 "iops_wr": 10, 103 } 104 # Pick each out of all possible params and test 105 for tk in params: 106 limits = dict([(k, 0) for k in params]) 107 limits[tk] = params[tk] 108 self.do_test_throttle(5, limits) 109 110class ThrottleTestCoroutine(ThrottleTestCase): 111 test_img = "null-co://" 112 113if __name__ == '__main__': 114 iotests.main(supported_fmts=["raw"]) 115