tests/qemu-iotests/093

   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
  21 import iotests
  22
  23 class 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
 110 class ThrottleTestCoroutine(ThrottleTestCase):
 111     test_img = "null-co://"
 112
 113 if __name__ == '__main__':
 114     iotests.main(supported_fmts=["raw"])