test_fp16.py 23.3 KB
Newer Older
1
import torch
Jeff Rasley's avatar
Jeff Rasley committed
2
import apex
3
4
5
6
7
8
import deepspeed
import argparse
import pytest
import json
import os
from common import distributed_test
9
from simple_model import SimpleModel, SimpleOptimizer, random_dataloader, args_from_dict
10
11


12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
def test_lamb_fp32_grad_clip(tmpdir):
    config_dict = {
        "train_batch_size": 2,
        "steps_per_print": 1,
        "optimizer": {
            "type": "Lamb",
            "params": {
                "lr": 0.00015
            }
        },
        "gradient_clipping": 1.0
    }
    args = args_from_dict(tmpdir, config_dict)
    hidden_dim = 10

    model = SimpleModel(hidden_dim, empty_grad=False)

    @distributed_test(world_size=[1, 2])
    def _test_lamb_fp32_grad_clip(args, model, hidden_dim):
        model, _, _,_ = deepspeed.initialize(args=args,
                                             model=model,
                                             model_parameters=model.parameters())
        data_loader = random_dataloader(model=model,
                                        total_samples=50,
                                        hidden_dim=hidden_dim,
Jeff Rasley's avatar
Jeff Rasley committed
37
38
                                        device=model.device,
                                        dtype=torch.float)
39
        for n, batch in enumerate(data_loader):
Jeff Rasley's avatar
Jeff Rasley committed
40
            loss = model(batch[0], batch[1])
41
42
43
44
45
46
            model.backward(loss)
            model.step()

    _test_lamb_fp32_grad_clip(args=args, model=model, hidden_dim=hidden_dim)


47
48
49
50
51
52
53
def test_lamb_fp16_basic(tmpdir):
    config_dict = {
        "train_batch_size": 2,
        "steps_per_print": 1,
        "optimizer": {
            "type": "Lamb",
            "params": {
54
                "lr": 0.00015
55
56
            }
        },
57
        "gradient_clipping": 1.0,
58
59
60
61
        "fp16": {
            "enabled": True
        }
    }
62
    args = args_from_dict(tmpdir, config_dict)
63
64
65
66
67
68
69
70
    hidden_dim = 10

    model = SimpleModel(hidden_dim, empty_grad=False)

    @distributed_test(world_size=[1, 2])
    def _test_lamb_fp16_basic(args, model, hidden_dim):
        model, _, _,_ = deepspeed.initialize(args=args,
                                             model=model,
71
                                             model_parameters=model.parameters())
72
73
74
75
        data_loader = random_dataloader(model=model,
                                        total_samples=50,
                                        hidden_dim=hidden_dim,
                                        device=model.device)
76
77
78
79
80
81
82
83
84
85
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

    _test_lamb_fp16_basic(args=args, model=model, hidden_dim=hidden_dim)


def test_lamb_fp16_empty_grad(tmpdir):
    config_dict = {
Jeff Rasley's avatar
Jeff Rasley committed
86
        "train_batch_size": 2,
87
88
89
90
        "steps_per_print": 1,
        "optimizer": {
            "type": "Lamb",
            "params": {
91
                "lr": 0.00015
92
93
            }
        },
94
        "gradient_clipping": 1.0,
95
96
97
98
        "fp16": {
            "enabled": True
        }
    }
99
    args = args_from_dict(tmpdir, config_dict)
100
101
    hidden_dim = 10

Jeff Rasley's avatar
Jeff Rasley committed
102
    model = SimpleModel(hidden_dim, empty_grad=True, rank=args.local_rank)
103

Jeff Rasley's avatar
Jeff Rasley committed
104
    @distributed_test(world_size=[2])
105
106
107
    def _test_lamb_fp16_empty_grad(args, model, hidden_dim):
        model, _, _,_ = deepspeed.initialize(args=args,
                                             model=model,
108
                                             model_parameters=model.parameters())
109
110
111
112
        data_loader = random_dataloader(model=model,
                                        total_samples=50,
                                        hidden_dim=hidden_dim,
                                        device=model.device)
113
114
115
116
117
118
119
120
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

    _test_lamb_fp16_empty_grad(args=args, model=model, hidden_dim=hidden_dim)


Jeff Rasley's avatar
Jeff Rasley committed
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
def test_adam_fp32_empty_grad(tmpdir):
    config_dict = {
        "train_batch_size": 2,
        "steps_per_print": 1,
        "optimizer": {
            "type": "Adam",
            "params": {
                "lr": 0.00015
            }
        },
        "gradient_clipping": 1.0,
        "fp16": {
            "enabled": False
        }
    }
    args = args_from_dict(tmpdir, config_dict)
    hidden_dim = 10

    model = SimpleModel(hidden_dim, empty_grad=True, rank=args.local_rank)

    @distributed_test(world_size=[2])
    def _test_adam_fp32_empty_grad(args, model, hidden_dim):
        model, _, _,_ = deepspeed.initialize(args=args,
                                             model=model,
                                             model_parameters=model.parameters())
        data_loader = random_dataloader(model=model,
                                        total_samples=50,
                                        hidden_dim=hidden_dim,
                                        device=model.device,
                                        dtype=torch.float)
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

    _test_adam_fp32_empty_grad(args=args, model=model, hidden_dim=hidden_dim)


159
160
161
162
163
164
165
166
def test_adamw_fp16_basic(tmpdir):
    config_dict = {
        "train_batch_size": 1,
        "steps_per_print": 1,
        "fp16": {
            "enabled": True
        }
    }
167
    args = args_from_dict(tmpdir, config_dict)
168
169
170
171
172
173
174
175
176
    hidden_dim = 10

    model = SimpleModel(hidden_dim, empty_grad=False)

    @distributed_test(world_size=[1])
    def _test_adamw_fp16_basic(args, model, hidden_dim):
        optimizer = torch.optim.AdamW(params=model.parameters())
        model, _, _,_ = deepspeed.initialize(args=args,
                                             model=model,
177
                                             optimizer=optimizer)
178
179
180
181
        data_loader = random_dataloader(model=model,
                                        total_samples=50,
                                        hidden_dim=hidden_dim,
                                        device=model.device)
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

    _test_adamw_fp16_basic(args=args, model=model, hidden_dim=hidden_dim)


def test_adamw_fp16_empty_grad(tmpdir):
    config_dict = {
        "train_batch_size": 1,
        "steps_per_print": 1,
        "fp16": {
            "enabled": True
        }
    }
198
    args = args_from_dict(tmpdir, config_dict)
199
200
201
202
203
204
205
206
207
    hidden_dim = 10

    model = SimpleModel(hidden_dim, empty_grad=True)

    @distributed_test(world_size=[1])
    def _test_adamw_fp16_empty_grad(args, model, hidden_dim):
        optimizer = torch.optim.AdamW(params=model.parameters())
        model, _, _,_ = deepspeed.initialize(args=args,
                                             model=model,
208
                                             optimizer=optimizer)
209
210
211
212
        data_loader = random_dataloader(model=model,
                                        total_samples=50,
                                        hidden_dim=hidden_dim,
                                        device=model.device)
213
214
215
216
217
218
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

    _test_adamw_fp16_empty_grad(args=args, model=model, hidden_dim=hidden_dim)
219
220


Jeff Rasley's avatar
Jeff Rasley committed
221
222
223
224
225
226
227
228
229
230
@pytest.mark.parametrize('zero_stage, use_cpu_offload',
                         [
                             (1,
                              False),
                             (2,
                              False),
                             (2,
                              True),
                         ])
def test_adam_fp16_zero_onecycle_compatibility(tmpdir, zero_stage, use_cpu_offload):
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
    config_dict = {
        "train_batch_size": 1,
        "steps_per_print": 1,
        "optimizer": {
            "type": "Adam",
            "params": {
                "lr": 0.00015
            }
        },
        "scheduler": {
            "type": "OneCycle",
            "params": {
                "cycle_first_step_size": 16000,
                "cycle_first_stair_count": 8000,
                "decay_step_size": 16000,
                "cycle_min_lr": 1e-06,
                "cycle_max_lr": 3e-05,
                "decay_lr_rate": 1e-07,
                "cycle_min_mom": 0.85,
                "cycle_max_mom": 0.99,
                "decay_mom_rate": 0.0
            }
        },
        "fp16": {
            "enabled": True
        },
Jeff Rasley's avatar
Jeff Rasley committed
257
        "zero_optimization": {
Jeff Rasley's avatar
Jeff Rasley committed
258
259
            "stage": zero_stage,
            "cpu_offload": use_cpu_offload
Jeff Rasley's avatar
Jeff Rasley committed
260
        }
261
    }
Jeff Rasley's avatar
Jeff Rasley committed
262

263
264
265
266
267
268
    args = args_from_dict(tmpdir, config_dict)
    hidden_dim = 10

    model = SimpleModel(hidden_dim, empty_grad=True)

    @distributed_test(world_size=[1])
Jeff Rasley's avatar
Jeff Rasley committed
269
    def _test_adam_fp16_zero_onecycle_compatibility(args, model, hidden_dim):
270
271
272
273
274
275
276
277
278
279
280
281
        model, _, _,_ = deepspeed.initialize(args=args,
                                             model=model,
                                             model_parameters=model.parameters())
        data_loader = random_dataloader(model=model,
                                        total_samples=50,
                                        hidden_dim=hidden_dim,
                                        device=model.device)
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

Jeff Rasley's avatar
Jeff Rasley committed
282
283
284
    _test_adam_fp16_zero_onecycle_compatibility(args=args,
                                                model=model,
                                                hidden_dim=hidden_dim)
285
286


Jeff Rasley's avatar
Jeff Rasley committed
287
288
289
290
291
292
293
294
295
296
@pytest.mark.parametrize('zero_stage, use_cpu_offload',
                         [
                             (1,
                              False),
                             (2,
                              False),
                             (2,
                              True),
                         ])
def test_zero_static_scale(tmpdir, zero_stage, use_cpu_offload):
297
    config_dict = {
Jeff Rasley's avatar
Jeff Rasley committed
298
        "train_batch_size": 4,
299
300
301
302
303
304
305
306
        "steps_per_print": 1,
        "optimizer": {
            "type": "Adam",
            "params": {
                "lr": 0.00015
            }
        },
        "fp16": {
Jeff Rasley's avatar
Jeff Rasley committed
307
308
            "enabled": True,
            "loss_scale": 138.
309
        },
Jeff Rasley's avatar
Jeff Rasley committed
310
        "zero_optimization": {
Jeff Rasley's avatar
Jeff Rasley committed
311
312
            "stage": zero_stage,
            "cpu_offload": use_cpu_offload
Jeff Rasley's avatar
Jeff Rasley committed
313
        }
314
315
316
    }
    args = args_from_dict(tmpdir, config_dict)

Jeff Rasley's avatar
Jeff Rasley committed
317
318
319
320
321
322
323
    @distributed_test(world_size=2)
    def _test_zero_static_scale(args):
        hidden_dim = 10
        model = SimpleModel(hidden_dim, empty_grad=True)
        model, optim, _,_ = deepspeed.initialize(args=args,
                                            model=model,
                                            model_parameters=model.parameters())
324

Jeff Rasley's avatar
Jeff Rasley committed
325
326
327
328
329
        # Ensure the static scaler is configured.
        assert optim.dynamic_loss_scale == False
        assert optim.loss_scaler.loss_scale == 138.

        # Now make sure things work..
330
        data_loader = random_dataloader(model=model,
Jeff Rasley's avatar
Jeff Rasley committed
331
                                        total_samples=10,
332
333
334
335
336
337
338
                                        hidden_dim=hidden_dim,
                                        device=model.device)
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

Jeff Rasley's avatar
Jeff Rasley committed
339
    _test_zero_static_scale(args)
340
341


Jeff Rasley's avatar
Jeff Rasley committed
342
def test_zero_static_scale_deprecated_format(tmpdir):
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
    config_dict = {
        "train_batch_size": 4,
        "steps_per_print": 1,
        "optimizer": {
            "type": "Adam",
            "params": {
                "lr": 0.00015
            }
        },
        "fp16": {
            "enabled": True,
            "loss_scale": 138.
        },
        "zero_optimization": True
    }
    args = args_from_dict(tmpdir, config_dict)

    @distributed_test(world_size=2)
    def _test_zero_static_scale(args):
        hidden_dim = 10
        model = SimpleModel(hidden_dim, empty_grad=True)
        model, optim, _,_ = deepspeed.initialize(args=args,
                                            model=model,
                                            model_parameters=model.parameters())

        # Ensure the static scaler is configured.
        assert optim.dynamic_loss_scale == False
        assert optim.loss_scaler.loss_scale == 138.

        # Now make sure things work..
        data_loader = random_dataloader(model=model,
                                        total_samples=10,
                                        hidden_dim=hidden_dim,
                                        device=model.device)
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

    _test_zero_static_scale(args)
383
384


Jeff Rasley's avatar
Jeff Rasley committed
385
386
387
388
389
390
391
392
393
394
@pytest.mark.parametrize('zero_stage, use_cpu_offload',
                         [
                             (1,
                              False),
                             (2,
                              False),
                             (2,
                              True),
                         ])
def test_zero_allow_untested_optimizer(tmpdir, zero_stage, use_cpu_offload):
395
396
397
398
399
400
    config_dict = {
        "train_batch_size": 4,
        "steps_per_print": 1,
        "fp16": {
            "enabled": True,
        },
Jeff Rasley's avatar
Jeff Rasley committed
401
        "zero_optimization": {
Jeff Rasley's avatar
Jeff Rasley committed
402
403
            "stage": zero_stage,
            "cpu_offload": use_cpu_offload
Jeff Rasley's avatar
Jeff Rasley committed
404
        },
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
        "zero_allow_untested_optimizer": False
    }
    args = args_from_dict(tmpdir, config_dict)

    @distributed_test(world_size=[1])
    def _test_zero_allow_untested_optimizer(args):
        hidden_dim = 10
        model = SimpleModel(hidden_dim, empty_grad=True)
        optimizer = SimpleOptimizer(model.parameters())
        with pytest.raises(AssertionError):
            model, optim, _,_ = deepspeed.initialize(args=args,
                                                    model=model,
                                                    optimizer=optimizer,
                                                    model_parameters=model.parameters())

    _test_zero_allow_untested_optimizer(args)
421
422


Jeff Rasley's avatar
Jeff Rasley committed
423
424
425
426
427
428
429
430
431
432
@pytest.mark.parametrize('zero_stage, use_cpu_offload',
                         [
                             (1,
                              False),
                             (2,
                              False),
                             (2,
                              True),
                         ])
def test_zero_empty_partition(tmpdir, zero_stage, use_cpu_offload):
433
434
435
436
437
438
439
440
441
442
443
444
445
446
    config_dict = {
        "train_micro_batch_size_per_gpu": 1,
        "gradient_accumulation_steps": 1,
        "fp16": {
            "enabled": True,
            "initial_scale_power": 8
        },
        "optimizer": {
            "type": "Adam",
            "params": {
                "lr": 0.00015
            }
        },
        "zero_optimization": {
Jeff Rasley's avatar
Jeff Rasley committed
447
            "stage": zero_stage,
Jeff Rasley's avatar
Jeff Rasley committed
448
449
450
            "cpu_offload": use_cpu_offload,
            "reduce_bucket_size": 100,
            "allgather_bucket_size": 100
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
        }
    }
    args = args_from_dict(tmpdir, config_dict)

    @distributed_test(world_size=[3])
    def _test_zero_empty_partition(args):
        hidden_dim = 1
        model = SimpleModel(hidden_dim)
        # Ensure model has 2 parameters, to cause empty partition with DP=3
        assert len(list(model.parameters())) == 2
        model, _, _, _ = deepspeed.initialize(args=args,
                                              model=model,
                                              model_parameters=model.parameters())

        # Now make sure things work..
        data_loader = random_dataloader(model=model,
                                        total_samples=1,
                                        hidden_dim=hidden_dim,
                                        device=model.device)
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

    _test_zero_empty_partition(args)
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575


def test_adam_amp_basic(tmpdir):
    config_dict = {"train_batch_size": 1, "steps_per_print": 1, "amp": {"enabled": True}}
    args = args_from_dict(tmpdir, config_dict)
    hidden_dim = 10

    model = SimpleModel(hidden_dim, empty_grad=False)

    @distributed_test(world_size=[1])
    def _test_adam_amp_basic(args, model, hidden_dim):
        optimizer = torch.optim.Adam(params=model.parameters())
        model, _, _,_ = deepspeed.initialize(args=args,
                                             model=model,
                                             optimizer=optimizer)
        data_loader = random_dataloader(model=model,
                                        total_samples=50,
                                        hidden_dim=hidden_dim,
                                        device=model.device)
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

    _test_adam_amp_basic(args=args, model=model, hidden_dim=hidden_dim)


def test_lamb_amp_basic(tmpdir):
    config_dict = {
        "train_batch_size": 2,
        "steps_per_print": 1,
        "optimizer": {
            "type": "Lamb",
            "params": {
                "lr": 0.00015
            }
        },
        "gradient_clipping": 1.0,
        "amp": {
            "enabled": True,
        }
    }
    args = args_from_dict(tmpdir, config_dict)
    hidden_dim = 10

    model = SimpleModel(hidden_dim, empty_grad=False)

    @distributed_test(world_size=[1, 2])
    def _test_lamb_amp_basic(args, model, hidden_dim):
        model, _, _,_ = deepspeed.initialize(args=args,
                                             model=model,
                                             model_parameters=model.parameters())
        data_loader = random_dataloader(model=model,
                                        total_samples=50,
                                        hidden_dim=hidden_dim,
                                        device=model.device)
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

    _test_lamb_amp_basic(args=args, model=model, hidden_dim=hidden_dim)


def test_adam_amp_o2(tmpdir):
    config_dict = {
        "train_batch_size": 2,
        "steps_per_print": 1,
        "optimizer": {
            "type": "Adam",
            "params": {
                "lr": 0.00015
            }
        },
        "gradient_clipping": 1.0,
        "amp": {
            "enabled": True,
            "opt_level": "O2"
        }
    }
    args = args_from_dict(tmpdir, config_dict)
    hidden_dim = 10

    model = SimpleModel(hidden_dim, empty_grad=False)

    @distributed_test(world_size=[1, 2])
    def _test_adam_amp_o2(args, model, hidden_dim):
        model, _, _,_ = deepspeed.initialize(args=args,
                                             model=model,
                                             model_parameters=model.parameters())
        data_loader = random_dataloader(model=model,
                                        total_samples=50,
                                        hidden_dim=hidden_dim,
                                        device=model.device)
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

    _test_adam_amp_o2(args=args, model=model, hidden_dim=hidden_dim)
Jeff Rasley's avatar
Jeff Rasley committed
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613


def test_adam_amp_o2_empty_grad(tmpdir):
    config_dict = {
        "train_batch_size": 2,
        "steps_per_print": 1,
        "optimizer": {
            "type": "Adam",
            "params": {
                "lr": 0.00015
            }
        },
        "gradient_clipping": 1.0,
        "amp": {
            "enabled": True,
            "opt_level": "O2"
        }
    }
    args = args_from_dict(tmpdir, config_dict)
    hidden_dim = 10

    model = SimpleModel(hidden_dim, empty_grad=False, rank=args.local_rank)

    @distributed_test(world_size=[2])
    def _test_adam_amp_o2_empty_grad(args, model, hidden_dim):
        model, _, _,_ = deepspeed.initialize(args=args,
                                             model=model,
                                             model_parameters=model.parameters())
        data_loader = random_dataloader(model=model,
                                        total_samples=50,
                                        hidden_dim=hidden_dim,
                                        device=model.device)
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

    _test_adam_amp_o2_empty_grad(args=args, model=model, hidden_dim=hidden_dim)
Jeff Rasley's avatar
Jeff Rasley committed
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693


@pytest.mark.parametrize('zero_stage, optimizer_constructor',
                         [(1,
                           apex.optimizers.FusedAdam),
                          (2,
                           torch.optim.Adam),
                          (2,
                           apex.optimizers.FusedAdam)])
def test_zero_supported_client_optimizer(tmpdir, zero_stage, optimizer_constructor):
    config_dict = {
        "train_batch_size": 2,
        "steps_per_print": 1,
        "fp16": {
            "enabled": True
        },
        "zero_optimization": {
            "stage": zero_stage
        }
    }
    args = args_from_dict(tmpdir, config_dict)
    hidden_dim = 10

    model = SimpleModel(hidden_dim, empty_grad=False)

    @distributed_test(world_size=[1])
    def _test_zero_supported_client_optimizer(args, model, optimizer_constructor):
        client_optimizer = optimizer_constructor(params=model.parameters())
        model, _, _, _ = deepspeed.initialize(args=args,
                                               model=model,
                                               optimizer=client_optimizer)

    _test_zero_supported_client_optimizer(args=args,
                                          model=model,
                                          optimizer_constructor=optimizer_constructor)


def test_zero2_reduce_scatter_off(tmpdir):
    config_dict = {
        "train_batch_size": 2,
        "steps_per_print": 1,
        "optimizer": {
            "type": "Adam",
            "params": {
                "lr": 0.00015
            }
        },
        "gradient_clipping": 1.0,
        "zero_optimization": {
            "stage": 2,
            "contiguous_gradients": True,
            "allgather_bucket_size": 2000000000,
            "reduce_bucket_size": 200000000,
            "overlap_comm": False,
            "reduce_scatter": False
        },
        "fp16": {
            "enabled": True
        }
    }
    args = args_from_dict(tmpdir, config_dict)
    hidden_dim = 10

    model = SimpleModel(hidden_dim, rank=args.local_rank)

    @distributed_test(world_size=[2])
    def _helper(args, model, hidden_dim):
        model, _, _,_ = deepspeed.initialize(args=args,
                                             model=model,
                                             model_parameters=model.parameters())
        data_loader = random_dataloader(model=model,
                                        total_samples=50,
                                        hidden_dim=hidden_dim,
                                        device=model.device)
        for n, batch in enumerate(data_loader):
            loss = model(batch[0], batch[1])
            model.backward(loss)
            model.step()

    _helper(args=args, model=model, hidden_dim=hidden_dim)