fix the bug in pipeline data parallelism (#29731)

* update, test=develop

python/paddle/distributed/fleet/meta_optimizers/pipeline_optimizer.py

@@ -41,35 +41,36 @@ class PipelineHelper(object):
                                inner_parallelism=None):
         self.startup_program = startup_program
 
-        endpoints = self.role_maker._get_trainer_endpoints()
-        current_endpoint = endpoints[self.role_maker._worker_index()]
-        node_num = _get_node_num(endpoints)
-        assert len(endpoints) % node_num == 0
         nranks = self.role_maker._worker_num()
         rank = self.role_maker._worker_index()
+        endpoints = self.role_maker._get_trainer_endpoints()
+        current_endpoint = endpoints[rank]
+        node_num = _get_node_num(endpoints)
+        assert nranks % node_num == 0
 
-        # Create ring 0 for all gpus in a pipeline
-        pipeline_endpoints = []
+        # Create ring 0 for all gpus in the same pipeline
+        if inner_parallelism > 1:
             pipeline_rank = rank % inner_parallelism
             pipeline_id = rank // inner_parallelism
-        for idx, ep in enumerate(endpoints):
-            if idx // inner_parallelism == pipeline_id:
-                pipeline_endpoints.append(ep)
+            start_index = pipeline_id * inner_parallelism
+            pipeline_endpoints = endpoints[start_index:start_index +
+                                           inner_parallelism]
             self._init_communicator(self.startup_program, current_endpoint,
                                     pipeline_endpoints, pipeline_rank, 0,
                                     self.wait_port)
 
         pipeline_num = len(endpoints) // inner_parallelism
         if pipeline_num == 1: return
-        # Create rings for gpus with the same gpu id
+        # Create rings for gpus with the same pipeline id for data parallel
         eps = []
-        local_rank = self.role_maker._worker_index() % inner_parallelism
-        ring_id = local_rank + 1
+        pipeline_rank = rank % inner_parallelism
+        ring_id = pipeline_rank + 1
         for i in range(pipeline_num):
-            eps.append(endpoints[i * inner_parallelism + local_rank])
-        temp_rank = self.role_maker._worker_index() // inner_parallelism
+            eps.append(endpoints[i * inner_parallelism + pipeline_rank])
+        # rank in a ring of gpus with the same pipeline id for data parallel
+        dp_rank = rank // inner_parallelism
         self._init_communicator(self.startup_program, current_endpoint, eps,
-                                temp_rank, ring_id, self.wait_port)
+                                dp_rank, ring_id, self.wait_port)
         self._broadcast_params(ring_id)
 
     def _init_communicator(self, program, current_endpoint, endpoints, rank,
@@ -108,8 +109,10 @@ class PipelineHelper(object):
 
     def _broadcast_params(self, ring_id):
         block = self.startup_program.global_block()
-        for param in block.iter_parameters():
-            if param.is_distributed:
+        for var_name in block.vars:
+            if "nccl_id" in var_name: continue
+            param = block.var(var_name)
+            if not param.persistable:
                 continue
 
             block.append_op(
@@ -136,7 +139,7 @@ class PipelineOptimizer(MetaOptimizerBase):
         self.inner_opt = optimizer
         # we do not allow meta optimizer to be inner optimizer currently
         self.meta_optimizers_white_list = []
-        self.meta_optimizers_black_list = []
+        self.meta_optimizers_black_list = ["GraphExecutionOptimizer", ]
 
     def _set_basic_info(self, loss, role_maker, user_defined_optimizer,
                         user_defined_strategy):
@@ -161,14 +164,6 @@ class PipelineOptimizer(MetaOptimizerBase):
         dist_strategy.pipeline = True
         dist_strategy.pipeline_configs = {"micro_batch": 1, }
 
-    def _get_local_rank(self, current_endpoint, endpoints):
-        cur_node_endpoints = []
-        cur_ip = current_endpoint.split(':')[0].strip()
-        for ep in endpoints:
-            if cur_ip == ep.split(':')[0].strip():
-                cur_node_endpoints.append(ep)
-        return cur_node_endpoints.index(current_endpoint)
-
     def minimize_impl(self,
                       loss,
                       startup_program=None,
@@ -176,56 +171,51 @@ class PipelineOptimizer(MetaOptimizerBase):
                       no_grad_set=None):
         endpoints = self.role_maker._get_trainer_endpoints()
         current_endpoint = endpoints[self.role_maker._worker_index()]
-        self.local_rank = self._get_local_rank(current_endpoint, endpoints)
         self.wrapped_opt = PO(self.inner_opt,
-                              num_microbatches=self.num_microbatches,
-                              start_cpu_core_id=self.local_rank)
+                              num_microbatches=self.num_microbatches)
         node_num = _get_node_num(endpoints)
         gpus_per_node = len(endpoints) // node_num
         self.startup_program = startup_program
-        self.local_rank = self._get_local_rank(current_endpoint, endpoints)
         if startup_program is None:
             self.startup_program = fluid.default_startup_program()
 
-        loss.block.program._pipeline_opt = dict()
-        loss.block.program._pipeline_opt['local_rank'] = self.local_rank
-        optimize_ops, params_grads, prog_list = \
-            self.wrapped_opt.minimize(loss, startup_program,
-                                      parameter_list, no_grad_set)
+        self.rank = self.role_maker._worker_index()
+        self.nranks = self.role_maker._worker_num()
+        assert self.nranks % node_num == 0
 
+        loss.block.program._pipeline_opt = dict()
+        loss.block.program._pipeline_opt['local_rank'] = self.rank
+        optimize_ops, params_grads, prog_list = self.wrapped_opt.minimize(
+            loss, startup_program, parameter_list, no_grad_set)
         assert prog_list
+
         self.main_program_list = prog_list
         self.main_program = loss.block.program
         self.inner_parallelism = loss.block.program._pipeline_opt[
             'inner_parallelism']
-        nranks = len(endpoints)
-        self.nranks = nranks
-        self.nrings = len(self.main_program_list)
-
-        self.rank = self.role_maker._worker_index()
-        self.endpoints = endpoints
-        self.current_endpoint = current_endpoint
+        assert self.nranks % self.inner_parallelism == 0
 
         pipeline_helper = PipelineHelper(self.role_maker)
         pipeline_helper.update_startup_program(
             self.startup_program._pipeline_opt["startup_program"],
             self.inner_parallelism)
 
-        self._transpile_main_program(loss, node_num, gpus_per_node)
+        pipeline_num = self.nranks // self.inner_parallelism
+        self._transpile_main_program(loss, pipeline_num, self.inner_parallelism)
         return optimize_ops, params_grads
 
-    def _transpile_main_program(self, loss, node_num, gpus_per_node):
-        self._insert_loss_grad_ops(loss, gpus_per_node, node_num)
-        for ring_id in range(1, gpus_per_node + 1):
+    def _transpile_main_program(self, loss, pipeline_num, inner_parallelism):
+        if pipeline_num <= 1: return
+        self._insert_loss_grad_ops(loss, pipeline_num)
+        for ring_id in range(1, inner_parallelism + 1):
             self._insert_allreduce_ops(ring_id)
 
-    def _insert_loss_grad_ops(self, loss, gpus_per_node, node_num):
+    def _insert_loss_grad_ops(self, loss, pipeline_num):
         """
         In order to keep the learning rate consistent in different numbers of
         training workers, we scale the loss grad by the number of workers
         """
-        block = self.main_program_list[gpus_per_node - 1][
-            'program'].global_block()
+        block = self.main_program_list[-1]['program'].global_block()
         for idx, op in reversed(list(enumerate(block.ops))):
             if is_loss_grad_op(op):
                 loss_grad_var = block.vars[op.output_arg_names[0]]
@@ -235,7 +225,7 @@ class PipelineOptimizer(MetaOptimizerBase):
                     inputs={'X': loss_grad_var},
                     outputs={'Out': loss_grad_var},
                     attrs={
-                        'scale': 1.0 / node_num,
+                        'scale': 1.0 / pipeline_num,
                         OP_ROLE_KEY: OpRole.Backward
                     })
 
@@ -269,7 +259,7 @@ class PipelineOptimizer(MetaOptimizerBase):
 
                     block._insert_op(
                         offset,
-                        type='c_sync_calc_stream',
+                        type='c_allreduce_sum',
                         inputs={'X': grad},
                         outputs={'Out': grad},
                         attrs={
@@ -283,7 +273,7 @@ class PipelineOptimizer(MetaOptimizerBase):
         for idx, op in enumerate(block.ops):
             if is_optimizer_op(op):
                 block._insert_op(
-                    idx + ring_id,
+                    idx,
                     type='c_sync_comm_stream',
                     inputs={'X': grad},
                     outputs={'Out': grad},

python/paddle/fluid/optimizer.py

@@ -16,6 +16,7 @@ from __future__ import print_function
 
 import numpy as np
 import six
+import os
 import logging
 from collections import defaultdict
 
@@ -39,6 +40,7 @@ from .dygraph.learning_rate_scheduler import LearningRateDecay, _LearningRateEpo
 from paddle.fluid import core
 from paddle.fluid.layers import tensor
 from functools import reduce
+from functools import cmp_to_key
 from .wrapped_decorator import signature_safe_contextmanager
 from .. import compat as cpt
 
@@ -3773,7 +3775,7 @@ class PipelineOptimizer(object):
         self._op_device_key = op_maker.kOpDeviceAttrName()
         self._param_device_map = None
 
-    def _create_vars(self, block, main_program):
+    def _create_vars(self, block, ori_block):
         # Create vars for block, copied from main_program's global block
         used_var_set = set()
         for op_idx in range(block.desc.op_size()):
@@ -3785,7 +3787,8 @@ class PipelineOptimizer(object):
                 if var in used_var_set or "_blocking_queue" in var:
                     continue
                 used_var_set.add(var)
-                source_var = main_program.block(0).var(str(var))
+                if block._find_var_recursive(str(var)): continue
+                source_var = ori_block._var_recursive(str(var))
                 if source_var.type == core.VarDesc.VarType.READER:
                     block.create_var(
                         name=var,
@@ -3840,45 +3843,65 @@ class PipelineOptimizer(object):
                     op_desc = op.desc
                     ap_op = program["program"].block(0).desc.append_op()
                     ap_op.copy_from(op_desc)
-                    ap_op._set_attr(self._op_device_key, "")
-            elif op.type == "create_py_reader" or op.type == "read":
+                    # ap_op._set_attr(self._op_device_key, "")
+            elif op.type == "create_py_reader" or op.type == "read" or op.type == "create_double_buffer_reader":
                 # Copy read related ops to all section to make them exit after each epoch.
                 for device in device_program_map.keys():
                     program = device_program_map[device]
                     op_desc = op.desc
                     ap_op = program["program"].block(0).desc.append_op()
                     ap_op.copy_from(op_desc)
-                    ap_op._set_attr(self._op_device_key, "")
             else:
                 program = device_program_map[device]
                 op_desc = op.desc
                 ap_op = program["program"].block(0).desc.append_op()
                 ap_op.copy_from(op_desc)
-                ap_op._set_attr(self._op_device_key, "")
 
-        for key in sorted(device_program_map.keys()):
+        for key in devices:
             program = device_program_map[key]
             program['program']._sync_with_cpp()
             programs.append(program)
 
         return programs
 
+    def _get_op_device_for_startup_program(self, var_name):
+        """
+        For adam optimizer, it will add accumulators and initialize them
+        with fill_constant, and force the op device to cpu. Hence, we should
+        get the real op_device attribute of the fill_constant as the device
+        where the corresponding parameters on.
+        """
+        assert "beta1_pow_acc" in var_name or "beta2_pow_acc" in var_name
+        param_name = var_name[0:var_name.index('_beta')]
+        device = self._param_device_map[param_name]
+        return device
+
     def _split_startup_program(self, startup_program, local_rank):
         block = startup_program.block(0)
         new_startup_program = Program()
         for op in block.ops:
             device = op.attr(self._op_device_key)
+            if device == "cpu":
+                assert op.type == "fill_constant", (
+                    "For ops in startup "
+                    "program that with the op_device attribute of cpu, "
+                    "they must be fill_constant.")
+                output_var = op.output_arg_names[0]
+                device = self._get_op_device_for_startup_program(output_var)
+
             if device:
-                device_index = int(device.split(":")[1])
+                device_index = int(device.split(':')[1])
             else:
-                device_index = None
-            if device_index is not None and device_index != local_rank: continue
+                # LR related ops
+                device = None
+            if device and device_index != local_rank: continue
             op_desc = op.desc
             ap_op = new_startup_program.block(0).desc.append_op()
             ap_op.copy_from(op_desc)
             ap_op._set_attr(self._op_device_key, "")
         new_startup_program._sync_with_cpp()
-        self._create_vars(new_startup_program.block(0), startup_program)
+        self._create_vars(
+            new_startup_program.block(0), startup_program.global_block())
         return new_startup_program
 
     def _find_post_op(self, ops, cur_op, var_name):
@@ -4093,6 +4116,8 @@ class PipelineOptimizer(object):
                 first_device = op.attr(self._op_device_key)
                 break
         assert first_device
+        first_device_type = first_device.split(":")[0]
+        assert first_device_type == "gpu"
 
         # set op_device attr for lr-related ops
         lrsched_role = int(self._op_role.LRSched)
@@ -4136,10 +4161,11 @@ class PipelineOptimizer(object):
             dev_spec = op.attr(self._op_device_key)
             assert dev_spec, ("op_device attribute for op "
                               "{} has not been set.".format(op.type))
+            dev_type = dev_spec.split(':')[0]
+            assert dev_type == "gpu", ("Now only gpu devices are supported "
+                                       "for pipeline parallelism.")
             if not dev_spec in device_specs:
                 device_specs.append(dev_spec)
-        sorted_device_specs = sorted(device_specs)
-        assert sorted_device_specs == device_specs
         return device_specs
 
     def _insert_sendrecv_ops_for_boundaries(self, block):
@@ -4216,6 +4242,7 @@ class PipelineOptimizer(object):
             device = self._param_device_map[param_name]
             if device != dev_spec: continue
             grad_name = self._append_grad_suffix(param_name)
+            if not main_block.has_var(grad_name): continue
             grad_var = main_block.vars[grad_name]
             main_block._insert_op(
                 index=0,
@@ -4297,6 +4324,7 @@ class PipelineOptimizer(object):
                     ap_op = new_sub_block.desc.append_op()
                     ap_op.copy_from(op_desc)
                 new_sub_block._sync_with_cpp()
+                self._create_vars(new_sub_block, origin_sub_block)
                 op._set_attr('sub_block:', new_sub_block)
 
     def _get_device_info(self, block):
@@ -4318,6 +4346,7 @@ class PipelineOptimizer(object):
             prog = prog_info['program']
             block = prog.block(0)
             for var_name in block.vars:
+                if var_name == "double_buffer_0": continue
                 var = block.var(var_name)
                 if not var.persistable: continue
                 if not var_name in var_info:
@@ -4413,30 +4442,33 @@ class PipelineOptimizer(object):
         self._add_default_opdevice_attr(main_block)
 
         device_specs = self._check_validation(main_block)
-        assert len(device_specs) > 1
+
+        def device_cmp(device1, device2):
+            dev1_id = int(device1.split(':')[1])
+            dev2_id = int(device2.split(':')[1])
+            if dev1_id < dev2_id:
+                return -1
+            elif dev1_id > dev2_id:
+                return 1
+            else:
+                return 0
+
+        sorted_device_spec = sorted(device_specs, key=cmp_to_key(device_cmp))
+        assert sorted_device_spec == device_specs, (
+            "With pipeline "
+            "parallelism, you must use gpu devices one after another "
+            "in the order of their ids.")
 
         # Step3: add send and recv ops between section boundaries
         self._insert_sendrecv_ops_for_boundaries(main_block)
 
-        place_list = []
-        place_id_list = []
-        for dev_spec in device_specs:
-            if dev_spec == "cpu":
-                place_list.append(core.CPUPlace())
-                place_id_list.append(-1)
-            elif "gpu" in dev_spec and ":" in dev_spec:
-                dev_index = dev_spec.split(":")[1]
-                place_list.append(core.CUDAPlace(int(dev_index)))
-                place_id_list.append(int(dev_index))
-            else:
-                raise ValueError("Unknown device type: %s", dev_spec)
-
         # Step4: split program into sections and add pairs of
         # send and recv ops for data var.
         main_program = main_block.program
         program_list = self._split_program(main_program, device_specs)
         for p in program_list:
-            self._create_vars(p["program"].block(0), main_program)
+            self._create_vars(p["program"].block(0),
+                              main_program.global_block())
         self._insert_sendrecv_for_data_var(main_block, program_list,
                                            startup_program, device_specs)
 
@@ -4452,7 +4484,13 @@ class PipelineOptimizer(object):
                 isinstance(main_program._pipeline_opt, dict) and
                 'local_rank' in main_program._pipeline_opt), \
                 "You must use pipeline with fleet"
-        local_rank = main_program._pipeline_opt['local_rank']
+        local_rank = main_program._pipeline_opt['local_rank'] % len(
+            device_specs)
+
+        place_list = []
+        for dev_spec in device_specs:
+            dev_index = dev_spec.split(":")[1]
+            place_list.append(core.CUDAPlace(local_rank))
 
         # Step7: Split startup program
         new_startup_program = self._split_startup_program(startup_program,
@@ -4466,21 +4504,18 @@ class PipelineOptimizer(object):
         self._accumulate_gradients(program_list[local_rank]['program']
                                    .global_block())
 
-        with open("startup_prog_%d" % local_rank, 'w') as f:
-            f.writelines(str(new_startup_program))
-        with open("main_prog_%d" % local_rank, 'w') as f:
-            f.writelines(str(program_list[local_rank]['program']))
-
         startup_program._pipeline_opt = {
             "startup_program": new_startup_program,
         }
+
+        place_id = int(os.getenv("FLAGS_selected_gpus", "0"))
         main_program._pipeline_opt = {
             "trainer": "PipelineTrainer",
             "device_worker": "Section",
             "inner_parallelism": len(device_specs),
             "section_program": program_list[local_rank],
             "place": place_list[local_rank],
-            "place_id": place_id_list[local_rank],
+            "place_id": place_id,
             "sync_steps": -1,
             "num_microbatches": self._num_microbatches,
             "start_cpu_core_id": self._start_cpu_core_id,

python/paddle/fluid/tests/unittests/pipeline_mnist_one_device.py

+#   Copyright (c) 2018 PaddlePaddle Authors. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from __future__ import print_function
+
+import numpy as np
+import argparse
+import time
+import math
+
+import paddle
+import paddle.fluid as fluid
+import paddle.fluid.profiler as profiler
+from paddle.fluid import core
+import unittest
+from multiprocessing import Process
+import os
+import signal
+from functools import reduce
+from test_dist_base import TestDistRunnerBase, runtime_main
+import paddle.distributed.fleet as fleet
+
+paddle.enable_static()
+
+DTYPE = "float32"
+paddle.dataset.mnist.fetch()
+
+# Fix seed for test
+fluid.default_startup_program().random_seed = 1
+fluid.default_main_program().random_seed = 1
+
+
+def cnn_model(data):
+    conv_pool_1 = fluid.nets.simple_img_conv_pool(
+        input=data,
+        filter_size=5,
+        num_filters=20,
+        pool_size=2,
+        pool_stride=2,
+        act="relu",
+        param_attr=fluid.ParamAttr(initializer=fluid.initializer.Constant(
+            value=0.01)))
+    conv_pool_2 = fluid.nets.simple_img_conv_pool(
+        input=conv_pool_1,
+        filter_size=5,
+        num_filters=50,
+        pool_size=2,
+        pool_stride=2,
+        act="relu",
+        param_attr=fluid.ParamAttr(initializer=fluid.initializer.Constant(
+            value=0.01)))
+
+    SIZE = 10
+    input_shape = conv_pool_2.shape
+    param_shape = [reduce(lambda a, b: a * b, input_shape[1:], 1)] + [SIZE]
+    scale = (2.0 / (param_shape[0]**2 * SIZE))**0.5
+
+    predict = fluid.layers.fc(
+        input=conv_pool_2,
+        size=SIZE,
+        act="softmax",
+        param_attr=fluid.param_attr.ParamAttr(
+            initializer=fluid.initializer.Constant(value=0.01)))
+    return predict
+
+
+class TestDistMnist2x2(TestDistRunnerBase):
+    def get_model(self, batch_size=2, use_dgc=False, dist_strategy=None):
+        # Input data
+        device_id = 0
+        if dist_strategy:
+            fleet.init(is_collective=True)
+        with fluid.device_guard("gpu:0"):
+            images = fluid.layers.data(
+                name='pixel', shape=[1, 28, 28], dtype=DTYPE)
+            label = fluid.layers.data(name='label', shape=[1], dtype='int64')
+
+            if dist_strategy:
+                data_loader = fluid.io.DataLoader.from_generator(
+                    feed_list=[images, label],
+                    capacity=64,
+                    use_double_buffer=False,
+                    iterable=False)
+            # Train program
+            predict = cnn_model(images)
+        with fluid.device_guard("gpu:0"):
+            cost = fluid.layers.cross_entropy(input=predict, label=label)
+            avg_cost = fluid.layers.mean(x=cost)
+
+        # Evaluator
+        with fluid.device_guard("gpu:0"):
+            batch_size_tensor = fluid.layers.create_tensor(dtype='int64')
+            batch_acc = fluid.layers.accuracy(
+                input=predict, label=label, total=batch_size_tensor)
+
+        inference_program = fluid.default_main_program().clone()
+        base_lr = self.lr
+        passes = [30, 60, 80, 90]
+        steps_per_pass = 10
+        bd = [steps_per_pass * p for p in passes]
+        lr = [base_lr * (0.1**i) for i in range(len(bd) + 1)]
+        lr_val = fluid.layers.piecewise_decay(boundaries=bd, values=lr)
+        opt = fluid.optimizer.Momentum(learning_rate=lr_val, momentum=0.9)
+
+        # Reader
+        train_reader = paddle.batch(
+            paddle.dataset.mnist.test(), batch_size=batch_size)
+        test_reader = paddle.batch(
+            paddle.dataset.mnist.test(), batch_size=batch_size)
+
+        if dist_strategy:
+            strategy = fleet.DistributedStrategy()
+            strategy.pipeline = True
+            dist_opt = fleet.distributed_optimizer(
+                optimizer=opt, strategy=strategy)
+            dist_opt.minimize(avg_cost)
+        else:
+            opt.minimize(avg_cost)
+
+        if dist_strategy:
+            return inference_program, avg_cost, train_reader, test_reader, batch_acc, predict, data_loader
+        else:
+            return inference_program, avg_cost, train_reader, test_reader, batch_acc, predict
+
+
+if __name__ == "__main__":
+    runtime_main(TestDistMnist2x2)

python/paddle/fluid/tests/unittests/test_fleet_pipeline_meta_optimizer.py

@@ -50,7 +50,7 @@ class TestFleetMetaOptimizer(unittest.TestCase):
         strategy.pipeline = True
         strategy.pipeline_configs = {'micro_batch': 2}
 
-        optimizer = paddle.fluid.optimizer.SGD(learning_rate=0.01)
+        optimizer = paddle.fluid.optimizer.Adam(0.01)
         optimizer = fleet.distributed_optimizer(optimizer, strategy=strategy)
         optimizer.minimize(avg_cost)
 

python/paddle/fluid/tests/unittests/test_pipeline.py

@@ -40,6 +40,14 @@ class TestPipeline(TestDistBase):
                 check_error_log=True,
                 log_name=flag_name)
 
+    def test_dist_train_one_device(self):
+        import paddle.fluid as fluid
+        if fluid.core.is_compiled_with_cuda():
+            self.check_with_place(
+                "pipeline_mnist_one_device.py",
+                check_error_log=True,
+                log_name=flag_name)
+
 
 if __name__ == '__main__':
     unittest.main()