qemu

FORK: QEMU emulator
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      1 #!/usr/bin/env python3
      2 # group: throttle
      3 #
      4 # Tests for IO throttling
      5 #
      6 # Copyright (C) 2015 Red Hat, Inc.
      7 # Copyright (C) 2015-2016 Igalia, S.L.
      8 #
      9 # This program is free software; you can redistribute it and/or modify
     10 # it under the terms of the GNU General Public License as published by
     11 # the Free Software Foundation; either version 2 of the License, or
     12 # (at your option) any later version.
     13 #
     14 # This program is distributed in the hope that it will be useful,
     15 # but WITHOUT ANY WARRANTY; without even the implied warranty of
     16 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     17 # GNU General Public License for more details.
     18 #
     19 # You should have received a copy of the GNU General Public License
     20 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
     21 #
     22 
     23 import iotests
     24 
     25 nsec_per_sec = 1000000000
     26 
     27 class ThrottleTestCase(iotests.QMPTestCase):
     28     test_driver = "null-aio"
     29     max_drives = 3
     30 
     31     def blockstats(self, device):
     32         result = self.vm.qmp("query-blockstats")
     33         for r in result['return']:
     34             if r['device'] == device:
     35                 stat = r['stats']
     36                 return stat['rd_bytes'], stat['rd_operations'], stat['wr_bytes'], stat['wr_operations']
     37         raise Exception("Device not found for blockstats: %s" % device)
     38 
     39     def required_drivers(self):
     40         return [self.test_driver]
     41 
     42     @iotests.skip_if_unsupported(required_drivers)
     43     def setUp(self):
     44         self.vm = iotests.VM()
     45         for i in range(0, self.max_drives):
     46             self.vm.add_drive(self.test_driver + "://", "file.read-zeroes=on")
     47         self.vm.launch()
     48 
     49     def tearDown(self):
     50         self.vm.shutdown()
     51 
     52     def configure_throttle(self, ndrives, params):
     53         params['group'] = 'test'
     54 
     55         # Set the I/O throttling parameters to all drives
     56         for i in range(0, ndrives):
     57             params['device'] = 'drive%d' % i
     58             result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params)
     59             self.assert_qmp(result, 'return', {})
     60 
     61     def do_test_throttle(self, ndrives, seconds, params, first_drive = 0):
     62         def check_limit(limit, num):
     63             # IO throttling algorithm is discrete, allow 10% error so the test
     64             # is more robust
     65             return limit == 0 or \
     66                    (num < seconds * limit * 1.1 / ndrives
     67                    and num > seconds * limit * 0.9 / ndrives)
     68 
     69         # Set vm clock to a known value
     70         ns = seconds * nsec_per_sec
     71         self.vm.qtest("clock_step %d" % ns)
     72 
     73         # Submit enough requests so the throttling mechanism kicks
     74         # in. The throttled requests won't be executed until we
     75         # advance the virtual clock.
     76         rq_size = 512
     77         rd_nr = max(params['bps'] // rq_size // 2,
     78                     params['bps_rd'] // rq_size,
     79                     params['iops'] // 2,
     80                     params['iops_rd'])
     81         rd_nr *= seconds * 2
     82         rd_nr //= ndrives
     83         wr_nr = max(params['bps'] // rq_size // 2,
     84                     params['bps_wr'] // rq_size,
     85                     params['iops'] // 2,
     86                     params['iops_wr'])
     87         wr_nr *= seconds * 2
     88         wr_nr //= ndrives
     89 
     90         # Send I/O requests to all drives
     91         for i in range(rd_nr):
     92             for drive in range(0, ndrives):
     93                 idx = first_drive + drive
     94                 self.vm.hmp_qemu_io("drive%d" % idx, "aio_read %d %d" %
     95                                     (i * rq_size, rq_size))
     96 
     97         for i in range(wr_nr):
     98             for drive in range(0, ndrives):
     99                 idx = first_drive + drive
    100                 self.vm.hmp_qemu_io("drive%d" % idx, "aio_write %d %d" %
    101                                     (i * rq_size, rq_size))
    102 
    103         # We'll store the I/O stats for each drive in these arrays
    104         start_rd_bytes = [0] * ndrives
    105         start_rd_iops  = [0] * ndrives
    106         start_wr_bytes = [0] * ndrives
    107         start_wr_iops  = [0] * ndrives
    108         end_rd_bytes   = [0] * ndrives
    109         end_rd_iops    = [0] * ndrives
    110         end_wr_bytes   = [0] * ndrives
    111         end_wr_iops    = [0] * ndrives
    112 
    113         # Read the stats before advancing the clock
    114         for i in range(0, ndrives):
    115             idx = first_drive + i
    116             start_rd_bytes[i], start_rd_iops[i], start_wr_bytes[i], \
    117                 start_wr_iops[i] = self.blockstats('drive%d' % idx)
    118 
    119         self.vm.qtest("clock_step %d" % ns)
    120 
    121         # Read the stats after advancing the clock
    122         for i in range(0, ndrives):
    123             idx = first_drive + i
    124             end_rd_bytes[i], end_rd_iops[i], end_wr_bytes[i], \
    125                 end_wr_iops[i] = self.blockstats('drive%d' % idx)
    126 
    127         # Check that the I/O is within the limits and evenly distributed
    128         for i in range(0, ndrives):
    129             rd_bytes = end_rd_bytes[i] - start_rd_bytes[i]
    130             rd_iops = end_rd_iops[i] - start_rd_iops[i]
    131             wr_bytes = end_wr_bytes[i] - start_wr_bytes[i]
    132             wr_iops = end_wr_iops[i] - start_wr_iops[i]
    133 
    134             self.assertTrue(check_limit(params['bps'], rd_bytes + wr_bytes))
    135             self.assertTrue(check_limit(params['bps_rd'], rd_bytes))
    136             self.assertTrue(check_limit(params['bps_wr'], wr_bytes))
    137             self.assertTrue(check_limit(params['iops'], rd_iops + wr_iops))
    138             self.assertTrue(check_limit(params['iops_rd'], rd_iops))
    139             self.assertTrue(check_limit(params['iops_wr'], wr_iops))
    140 
    141         # Allow remaining requests to finish.  We submitted twice as many to
    142         # ensure the throttle limit is reached.
    143         self.vm.qtest("clock_step %d" % ns)
    144 
    145     # Connect N drives to a VM and test I/O in all of them
    146     def test_all(self):
    147         params = {"bps": 4096,
    148                   "bps_rd": 4096,
    149                   "bps_wr": 4096,
    150                   "iops": 10,
    151                   "iops_rd": 10,
    152                   "iops_wr": 10,
    153                  }
    154         # Repeat the test with different numbers of drives
    155         for ndrives in range(1, self.max_drives + 1):
    156             # Pick each out of all possible params and test
    157             for tk in params:
    158                 limits = dict([(k, 0) for k in params])
    159                 limits[tk] = params[tk] * ndrives
    160                 self.configure_throttle(ndrives, limits)
    161                 self.do_test_throttle(ndrives, 5, limits)
    162 
    163     # Connect N drives to a VM and test I/O in just one of them a time
    164     def test_one(self):
    165         params = {"bps": 4096,
    166                   "bps_rd": 4096,
    167                   "bps_wr": 4096,
    168                   "iops": 10,
    169                   "iops_rd": 10,
    170                   "iops_wr": 10,
    171                  }
    172         # Repeat the test for each one of the drives
    173         for drive in range(0, self.max_drives):
    174             # Pick each out of all possible params and test
    175             for tk in params:
    176                 limits = dict([(k, 0) for k in params])
    177                 limits[tk] = params[tk] * self.max_drives
    178                 self.configure_throttle(self.max_drives, limits)
    179                 self.do_test_throttle(1, 5, limits, drive)
    180 
    181     def test_burst(self):
    182         params = {"bps": 4096,
    183                   "bps_rd": 4096,
    184                   "bps_wr": 4096,
    185                   "iops": 10,
    186                   "iops_rd": 10,
    187                   "iops_wr": 10,
    188                  }
    189         ndrives = 1
    190         # Pick each out of all possible params and test
    191         for tk in params:
    192             rate = params[tk] * ndrives
    193             burst_rate = rate * 7
    194             burst_length = 4
    195 
    196             # Configure the throttling settings
    197             settings = dict([(k, 0) for k in params])
    198             settings[tk] = rate
    199             settings['%s_max' % tk] = burst_rate
    200             settings['%s_max_length' % tk] = burst_length
    201             self.configure_throttle(ndrives, settings)
    202 
    203             # Wait for the bucket to empty so we can do bursts
    204             wait_ns = nsec_per_sec * burst_length * burst_rate // rate
    205             self.vm.qtest("clock_step %d" % wait_ns)
    206 
    207             # Test I/O at the max burst rate
    208             limits = dict([(k, 0) for k in params])
    209             limits[tk] = burst_rate
    210             self.do_test_throttle(ndrives, burst_length, limits)
    211 
    212             # Now test I/O at the normal rate
    213             limits[tk] = rate
    214             self.do_test_throttle(ndrives, 5, limits)
    215 
    216     # Test that removing a drive from a throttle group should not
    217     # affect the remaining members of the group.
    218     # https://bugzilla.redhat.com/show_bug.cgi?id=1535914
    219     def test_remove_group_member(self):
    220         # Create a throttle group with two drives
    221         # and set a 4 KB/s read limit.
    222         params = {"bps": 0,
    223                   "bps_rd": 4096,
    224                   "bps_wr": 0,
    225                   "iops": 0,
    226                   "iops_rd": 0,
    227                   "iops_wr": 0 }
    228         self.configure_throttle(2, params)
    229 
    230         # Read 4KB from drive0. This is performed immediately.
    231         self.vm.hmp_qemu_io("drive0", "aio_read 0 4096")
    232 
    233         # Read 2KB. The I/O limit has been exceeded so this
    234         # request is throttled and a timer is set to wake it up.
    235         self.vm.hmp_qemu_io("drive0", "aio_read 0 2048")
    236 
    237         # Read 2KB again. We're still over the I/O limit so this is
    238         # request is also throttled, but no new timer is set since
    239         # there's already one.
    240         self.vm.hmp_qemu_io("drive0", "aio_read 0 2048")
    241 
    242         # Read from drive1. This request is also throttled, and no
    243         # timer is set in drive1 because there's already one in
    244         # drive0.
    245         self.vm.hmp_qemu_io("drive1", "aio_read 0 4096")
    246 
    247         # At this point only the first 4KB have been read from drive0.
    248         # The other requests are throttled.
    249         self.assertEqual(self.blockstats('drive0')[0], 4096)
    250         self.assertEqual(self.blockstats('drive1')[0], 0)
    251 
    252         # Remove drive0 from the throttle group and disable its I/O limits.
    253         # drive1 remains in the group with a throttled request.
    254         params['bps_rd'] = 0
    255         params['device'] = 'drive0'
    256         result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params)
    257         self.assert_qmp(result, 'return', {})
    258 
    259         # Removing the I/O limits from drive0 drains its two pending requests.
    260         # The read request in drive1 is still throttled.
    261         self.assertEqual(self.blockstats('drive0')[0], 8192)
    262         self.assertEqual(self.blockstats('drive1')[0], 0)
    263 
    264         # Advance the clock 5 seconds. This completes the request in drive1
    265         self.vm.qtest("clock_step %d" % (5 * nsec_per_sec))
    266 
    267         # Now all requests have been processed.
    268         self.assertEqual(self.blockstats('drive0')[0], 8192)
    269         self.assertEqual(self.blockstats('drive1')[0], 4096)
    270 
    271 class ThrottleTestCoroutine(ThrottleTestCase):
    272     test_driver = "null-co"
    273 
    274 class ThrottleTestGroupNames(iotests.QMPTestCase):
    275     max_drives = 3
    276 
    277     def setUp(self):
    278         self.vm = iotests.VM()
    279         for i in range(0, self.max_drives):
    280             self.vm.add_drive("null-co://",
    281                               "throttling.iops-total=100,file.read-zeroes=on")
    282         self.vm.launch()
    283 
    284     def tearDown(self):
    285         self.vm.shutdown()
    286 
    287     def set_io_throttle(self, device, params):
    288         params["device"] = device
    289         result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params)
    290         self.assert_qmp(result, 'return', {})
    291 
    292     def verify_name(self, device, name):
    293         result = self.vm.qmp("query-block")
    294         for r in result["return"]:
    295             if r["device"] == device:
    296                 info = r["inserted"]
    297                 if name:
    298                     self.assertEqual(info["group"], name)
    299                 else:
    300                     self.assertFalse('group' in info)
    301                 return
    302 
    303         raise Exception("No group information found for '%s'" % device)
    304 
    305     def test_group_naming(self):
    306         params = {"bps": 0,
    307                   "bps_rd": 0,
    308                   "bps_wr": 0,
    309                   "iops": 0,
    310                   "iops_rd": 0,
    311                   "iops_wr": 0}
    312 
    313         # Check the drives added using the command line.
    314         # The default throttling group name is the device name.
    315         for i in range(self.max_drives):
    316             devname = "drive%d" % i
    317             self.verify_name(devname, devname)
    318 
    319         # Clear throttling settings => the group name is gone.
    320         for i in range(self.max_drives):
    321             devname = "drive%d" % i
    322             self.set_io_throttle(devname, params)
    323             self.verify_name(devname, None)
    324 
    325         # Set throttling settings using block_set_io_throttle and
    326         # check the default group names.
    327         params["iops"] = 10
    328         for i in range(self.max_drives):
    329             devname = "drive%d" % i
    330             self.set_io_throttle(devname, params)
    331             self.verify_name(devname, devname)
    332 
    333         # Set a custom group name for each device
    334         for i in range(3):
    335             devname = "drive%d" % i
    336             groupname = "group%d" % i
    337             params['group'] = groupname
    338             self.set_io_throttle(devname, params)
    339             self.verify_name(devname, groupname)
    340 
    341         # Put drive0 in group1 and check that all other devices remain
    342         # unchanged
    343         params['group'] = 'group1'
    344         self.set_io_throttle('drive0', params)
    345         self.verify_name('drive0', 'group1')
    346         for i in range(1, self.max_drives):
    347             devname = "drive%d" % i
    348             groupname = "group%d" % i
    349             self.verify_name(devname, groupname)
    350 
    351         # Put drive0 in group2 and check that all other devices remain
    352         # unchanged
    353         params['group'] = 'group2'
    354         self.set_io_throttle('drive0', params)
    355         self.verify_name('drive0', 'group2')
    356         for i in range(1, self.max_drives):
    357             devname = "drive%d" % i
    358             groupname = "group%d" % i
    359             self.verify_name(devname, groupname)
    360 
    361         # Clear throttling settings from drive0 check that all other
    362         # devices remain unchanged
    363         params["iops"] = 0
    364         self.set_io_throttle('drive0', params)
    365         self.verify_name('drive0', None)
    366         for i in range(1, self.max_drives):
    367             devname = "drive%d" % i
    368             groupname = "group%d" % i
    369             self.verify_name(devname, groupname)
    370 
    371 class ThrottleTestRemovableMedia(iotests.QMPTestCase):
    372     def setUp(self):
    373         self.vm = iotests.VM()
    374         self.vm.add_device("{},id=virtio-scsi".format('virtio-scsi'))
    375         self.vm.launch()
    376 
    377     def tearDown(self):
    378         self.vm.shutdown()
    379 
    380     def test_removable_media(self):
    381         # Add a couple of dummy nodes named cd0 and cd1
    382         result = self.vm.qmp("blockdev-add", driver="null-co",
    383                              read_zeroes=True, node_name="cd0")
    384         self.assert_qmp(result, 'return', {})
    385         result = self.vm.qmp("blockdev-add", driver="null-co",
    386                              read_zeroes=True, node_name="cd1")
    387         self.assert_qmp(result, 'return', {})
    388 
    389         # Attach a CD drive with cd0 inserted
    390         result = self.vm.qmp("device_add", driver="scsi-cd",
    391                              id="dev0", drive="cd0")
    392         self.assert_qmp(result, 'return', {})
    393 
    394         # Set I/O limits
    395         args = { "id": "dev0", "iops": 100, "iops_rd": 0, "iops_wr": 0,
    396                                 "bps":  50,  "bps_rd": 0,  "bps_wr": 0 }
    397         result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **args)
    398         self.assert_qmp(result, 'return', {})
    399 
    400         # Check that the I/O limits have been set
    401         result = self.vm.qmp("query-block")
    402         self.assert_qmp(result, 'return[0]/inserted/iops', 100)
    403         self.assert_qmp(result, 'return[0]/inserted/bps',   50)
    404 
    405         # Now eject cd0 and insert cd1
    406         result = self.vm.qmp("blockdev-open-tray", id='dev0')
    407         self.assert_qmp(result, 'return', {})
    408         result = self.vm.qmp("blockdev-remove-medium", id='dev0')
    409         self.assert_qmp(result, 'return', {})
    410         result = self.vm.qmp("blockdev-insert-medium", id='dev0', node_name='cd1')
    411         self.assert_qmp(result, 'return', {})
    412 
    413         # Check that the I/O limits are still the same
    414         result = self.vm.qmp("query-block")
    415         self.assert_qmp(result, 'return[0]/inserted/iops', 100)
    416         self.assert_qmp(result, 'return[0]/inserted/bps',   50)
    417 
    418         # Eject cd1
    419         result = self.vm.qmp("blockdev-remove-medium", id='dev0')
    420         self.assert_qmp(result, 'return', {})
    421 
    422         # Check that we can't set limits if the device has no medium
    423         result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **args)
    424         self.assert_qmp(result, 'error/class', 'GenericError')
    425 
    426         # Remove the CD drive
    427         result = self.vm.qmp("device_del", id='dev0')
    428         self.assert_qmp(result, 'return', {})
    429 
    430 
    431 if __name__ == '__main__':
    432     if 'null-co' not in iotests.supported_formats():
    433         iotests.notrun('null-co driver support missing')
    434     iotests.main(supported_fmts=["raw"])