xref: /openbmc/qemu/tests/qemu-iotests/093 (revision b6aed193)
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
23import iotests
24
25nsec_per_sec = 1000000000
26
27class 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            self.vm.cmd("block_set_io_throttle", conv_keys=False, **params)
59
60    def do_test_throttle(self, ndrives, seconds, params, first_drive = 0):
61        def check_limit(limit, num):
62            # IO throttling algorithm is discrete, allow 10% error so the test
63            # is more robust
64            return limit == 0 or \
65                   (num < seconds * limit * 1.1 / ndrives
66                   and num > seconds * limit * 0.9 / ndrives)
67
68        # Set vm clock to a known value
69        ns = seconds * nsec_per_sec
70        self.vm.qtest("clock_step %d" % ns)
71
72        # Submit enough requests so the throttling mechanism kicks
73        # in. The throttled requests won't be executed until we
74        # advance the virtual clock.
75        rq_size = 512
76        rd_nr = max(params['bps'] // rq_size // 2,
77                    params['bps_rd'] // rq_size,
78                    params['iops'] // 2,
79                    params['iops_rd'])
80        rd_nr *= seconds * 2
81        rd_nr //= ndrives
82        wr_nr = max(params['bps'] // rq_size // 2,
83                    params['bps_wr'] // rq_size,
84                    params['iops'] // 2,
85                    params['iops_wr'])
86        wr_nr *= seconds * 2
87        wr_nr //= ndrives
88
89        # Send I/O requests to all drives
90        for i in range(rd_nr):
91            for drive in range(0, ndrives):
92                idx = first_drive + drive
93                self.vm.hmp_qemu_io("drive%d" % idx, "aio_read %d %d" %
94                                    (i * rq_size, rq_size))
95
96        for i in range(wr_nr):
97            for drive in range(0, ndrives):
98                idx = first_drive + drive
99                self.vm.hmp_qemu_io("drive%d" % idx, "aio_write %d %d" %
100                                    (i * rq_size, rq_size))
101
102        # We'll store the I/O stats for each drive in these arrays
103        start_rd_bytes = [0] * ndrives
104        start_rd_iops  = [0] * ndrives
105        start_wr_bytes = [0] * ndrives
106        start_wr_iops  = [0] * ndrives
107        end_rd_bytes   = [0] * ndrives
108        end_rd_iops    = [0] * ndrives
109        end_wr_bytes   = [0] * ndrives
110        end_wr_iops    = [0] * ndrives
111
112        # Read the stats before advancing the clock
113        for i in range(0, ndrives):
114            idx = first_drive + i
115            start_rd_bytes[i], start_rd_iops[i], start_wr_bytes[i], \
116                start_wr_iops[i] = self.blockstats('drive%d' % idx)
117
118        self.vm.qtest("clock_step %d" % ns)
119
120        # Read the stats after advancing the clock
121        for i in range(0, ndrives):
122            idx = first_drive + i
123            end_rd_bytes[i], end_rd_iops[i], end_wr_bytes[i], \
124                end_wr_iops[i] = self.blockstats('drive%d' % idx)
125
126        # Check that the I/O is within the limits and evenly distributed
127        for i in range(0, ndrives):
128            rd_bytes = end_rd_bytes[i] - start_rd_bytes[i]
129            rd_iops = end_rd_iops[i] - start_rd_iops[i]
130            wr_bytes = end_wr_bytes[i] - start_wr_bytes[i]
131            wr_iops = end_wr_iops[i] - start_wr_iops[i]
132
133            self.assertTrue(check_limit(params['bps'], rd_bytes + wr_bytes))
134            self.assertTrue(check_limit(params['bps_rd'], rd_bytes))
135            self.assertTrue(check_limit(params['bps_wr'], wr_bytes))
136            self.assertTrue(check_limit(params['iops'], rd_iops + wr_iops))
137            self.assertTrue(check_limit(params['iops_rd'], rd_iops))
138            self.assertTrue(check_limit(params['iops_wr'], wr_iops))
139
140        # Allow remaining requests to finish.  We submitted twice as many to
141        # ensure the throttle limit is reached.
142        self.vm.qtest("clock_step %d" % ns)
143
144    # Connect N drives to a VM and test I/O in all of them
145    def test_all(self):
146        params = {"bps": 4096,
147                  "bps_rd": 4096,
148                  "bps_wr": 4096,
149                  "iops": 10,
150                  "iops_rd": 10,
151                  "iops_wr": 10,
152                 }
153        # Repeat the test with different numbers of drives
154        for ndrives in range(1, self.max_drives + 1):
155            # Pick each out of all possible params and test
156            for tk in params:
157                limits = dict([(k, 0) for k in params])
158                limits[tk] = params[tk] * ndrives
159                self.configure_throttle(ndrives, limits)
160                self.do_test_throttle(ndrives, 5, limits)
161
162    # Connect N drives to a VM and test I/O in just one of them a time
163    def test_one(self):
164        params = {"bps": 4096,
165                  "bps_rd": 4096,
166                  "bps_wr": 4096,
167                  "iops": 10,
168                  "iops_rd": 10,
169                  "iops_wr": 10,
170                 }
171        # Repeat the test for each one of the drives
172        for drive in range(0, self.max_drives):
173            # Pick each out of all possible params and test
174            for tk in params:
175                limits = dict([(k, 0) for k in params])
176                limits[tk] = params[tk] * self.max_drives
177                self.configure_throttle(self.max_drives, limits)
178                self.do_test_throttle(1, 5, limits, drive)
179
180    def test_burst(self):
181        params = {"bps": 4096,
182                  "bps_rd": 4096,
183                  "bps_wr": 4096,
184                  "iops": 10,
185                  "iops_rd": 10,
186                  "iops_wr": 10,
187                 }
188        ndrives = 1
189        # Pick each out of all possible params and test
190        for tk in params:
191            rate = params[tk] * ndrives
192            burst_rate = rate * 7
193            burst_length = 4
194
195            # Configure the throttling settings
196            settings = dict([(k, 0) for k in params])
197            settings[tk] = rate
198            settings['%s_max' % tk] = burst_rate
199            settings['%s_max_length' % tk] = burst_length
200            self.configure_throttle(ndrives, settings)
201
202            # Wait for the bucket to empty so we can do bursts
203            wait_ns = nsec_per_sec * burst_length * burst_rate // rate
204            self.vm.qtest("clock_step %d" % wait_ns)
205
206            # Test I/O at the max burst rate
207            limits = dict([(k, 0) for k in params])
208            limits[tk] = burst_rate
209            self.do_test_throttle(ndrives, burst_length, limits)
210
211            # Now test I/O at the normal rate
212            limits[tk] = rate
213            self.do_test_throttle(ndrives, 5, limits)
214
215    # Test that removing a drive from a throttle group should not
216    # affect the remaining members of the group.
217    # https://bugzilla.redhat.com/show_bug.cgi?id=1535914
218    def test_remove_group_member(self):
219        # Create a throttle group with two drives
220        # and set a 4 KB/s read limit.
221        params = {"bps": 0,
222                  "bps_rd": 4096,
223                  "bps_wr": 0,
224                  "iops": 0,
225                  "iops_rd": 0,
226                  "iops_wr": 0 }
227        self.configure_throttle(2, params)
228
229        # Read 4KB from drive0. This is performed immediately.
230        self.vm.hmp_qemu_io("drive0", "aio_read 0 4096")
231
232        # Read 2KB. The I/O limit has been exceeded so this
233        # request is throttled and a timer is set to wake it up.
234        self.vm.hmp_qemu_io("drive0", "aio_read 0 2048")
235
236        # Read 2KB again. We're still over the I/O limit so this is
237        # request is also throttled, but no new timer is set since
238        # there's already one.
239        self.vm.hmp_qemu_io("drive0", "aio_read 0 2048")
240
241        # Read from drive1. This request is also throttled, and no
242        # timer is set in drive1 because there's already one in
243        # drive0.
244        self.vm.hmp_qemu_io("drive1", "aio_read 0 4096")
245
246        # At this point only the first 4KB have been read from drive0.
247        # The other requests are throttled.
248        self.assertEqual(self.blockstats('drive0')[0], 4096)
249        self.assertEqual(self.blockstats('drive1')[0], 0)
250
251        # Remove drive0 from the throttle group and disable its I/O limits.
252        # drive1 remains in the group with a throttled request.
253        params['bps_rd'] = 0
254        params['device'] = 'drive0'
255        self.vm.cmd("block_set_io_throttle", conv_keys=False, **params)
256
257        # Removing the I/O limits from drive0 drains its two pending requests.
258        # The read request in drive1 is still throttled.
259        self.assertEqual(self.blockstats('drive0')[0], 8192)
260        self.assertEqual(self.blockstats('drive1')[0], 0)
261
262        # Advance the clock 5 seconds. This completes the request in drive1
263        self.vm.qtest("clock_step %d" % (5 * nsec_per_sec))
264
265        # Now all requests have been processed.
266        self.assertEqual(self.blockstats('drive0')[0], 8192)
267        self.assertEqual(self.blockstats('drive1')[0], 4096)
268
269class ThrottleTestCoroutine(ThrottleTestCase):
270    test_driver = "null-co"
271
272class ThrottleTestGroupNames(iotests.QMPTestCase):
273    max_drives = 3
274
275    def setUp(self):
276        self.vm = iotests.VM()
277        for i in range(0, self.max_drives):
278            self.vm.add_drive("null-co://",
279                              "throttling.iops-total=100,file.read-zeroes=on")
280        self.vm.launch()
281
282    def tearDown(self):
283        self.vm.shutdown()
284
285    def set_io_throttle(self, device, params):
286        params["device"] = device
287        self.vm.cmd("block_set_io_throttle", conv_keys=False, **params)
288
289    def verify_name(self, device, name):
290        result = self.vm.qmp("query-block")
291        for r in result["return"]:
292            if r["device"] == device:
293                info = r["inserted"]
294                if name:
295                    self.assertEqual(info["group"], name)
296                else:
297                    self.assertFalse('group' in info)
298                return
299
300        raise Exception("No group information found for '%s'" % device)
301
302    def test_group_naming(self):
303        params = {"bps": 0,
304                  "bps_rd": 0,
305                  "bps_wr": 0,
306                  "iops": 0,
307                  "iops_rd": 0,
308                  "iops_wr": 0}
309
310        # Check the drives added using the command line.
311        # The default throttling group name is the device name.
312        for i in range(self.max_drives):
313            devname = "drive%d" % i
314            self.verify_name(devname, devname)
315
316        # Clear throttling settings => the group name is gone.
317        for i in range(self.max_drives):
318            devname = "drive%d" % i
319            self.set_io_throttle(devname, params)
320            self.verify_name(devname, None)
321
322        # Set throttling settings using block_set_io_throttle and
323        # check the default group names.
324        params["iops"] = 10
325        for i in range(self.max_drives):
326            devname = "drive%d" % i
327            self.set_io_throttle(devname, params)
328            self.verify_name(devname, devname)
329
330        # Set a custom group name for each device
331        for i in range(3):
332            devname = "drive%d" % i
333            groupname = "group%d" % i
334            params['group'] = groupname
335            self.set_io_throttle(devname, params)
336            self.verify_name(devname, groupname)
337
338        # Put drive0 in group1 and check that all other devices remain
339        # unchanged
340        params['group'] = 'group1'
341        self.set_io_throttle('drive0', params)
342        self.verify_name('drive0', 'group1')
343        for i in range(1, self.max_drives):
344            devname = "drive%d" % i
345            groupname = "group%d" % i
346            self.verify_name(devname, groupname)
347
348        # Put drive0 in group2 and check that all other devices remain
349        # unchanged
350        params['group'] = 'group2'
351        self.set_io_throttle('drive0', params)
352        self.verify_name('drive0', 'group2')
353        for i in range(1, self.max_drives):
354            devname = "drive%d" % i
355            groupname = "group%d" % i
356            self.verify_name(devname, groupname)
357
358        # Clear throttling settings from drive0 check that all other
359        # devices remain unchanged
360        params["iops"] = 0
361        self.set_io_throttle('drive0', params)
362        self.verify_name('drive0', None)
363        for i in range(1, self.max_drives):
364            devname = "drive%d" % i
365            groupname = "group%d" % i
366            self.verify_name(devname, groupname)
367
368class ThrottleTestRemovableMedia(iotests.QMPTestCase):
369    def setUp(self):
370        self.vm = iotests.VM()
371        self.vm.add_device("{},id=virtio-scsi".format('virtio-scsi'))
372        self.vm.launch()
373
374    def tearDown(self):
375        self.vm.shutdown()
376
377    def test_removable_media(self):
378        # Add a couple of dummy nodes named cd0 and cd1
379        self.vm.cmd("blockdev-add", driver="null-co",
380                    read_zeroes=True, node_name="cd0")
381        self.vm.cmd("blockdev-add", driver="null-co",
382                    read_zeroes=True, node_name="cd1")
383
384        # Attach a CD drive with cd0 inserted
385        self.vm.cmd("device_add", driver="scsi-cd",
386                    id="dev0", drive="cd0")
387
388        # Set I/O limits
389        args = { "id": "dev0", "iops": 100, "iops_rd": 0, "iops_wr": 0,
390                                "bps":  50,  "bps_rd": 0,  "bps_wr": 0 }
391        self.vm.cmd("block_set_io_throttle", conv_keys=False, **args)
392
393        # Check that the I/O limits have been set
394        result = self.vm.qmp("query-block")
395        self.assert_qmp(result, 'return[0]/inserted/iops', 100)
396        self.assert_qmp(result, 'return[0]/inserted/bps',   50)
397
398        # Now eject cd0 and insert cd1
399        self.vm.cmd("blockdev-open-tray", id='dev0')
400        self.vm.cmd("blockdev-remove-medium", id='dev0')
401        self.vm.cmd("blockdev-insert-medium", id='dev0', node_name='cd1')
402
403        # Check that the I/O limits are still the same
404        result = self.vm.qmp("query-block")
405        self.assert_qmp(result, 'return[0]/inserted/iops', 100)
406        self.assert_qmp(result, 'return[0]/inserted/bps',   50)
407
408        # Eject cd1
409        self.vm.cmd("blockdev-remove-medium", id='dev0')
410
411        # Check that we can't set limits if the device has no medium
412        result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **args)
413        self.assert_qmp(result, 'error/class', 'GenericError')
414
415        # Remove the CD drive
416        self.vm.cmd("device_del", id='dev0')
417
418
419if __name__ == '__main__':
420    if 'null-co' not in iotests.supported_formats():
421        iotests.notrun('null-co driver support missing')
422    iotests.main(supported_fmts=["raw"])
423