add dist_multi_trainer for distributed training, add trainer_factory and device_worker_factory so that we can easily extend new training mode, add pull dense worker which is a singleton for parameter fetching

* fuse optimizer

* Revert "[MKL-DNN] Fix to crash of Transformer when mkldnn is to be used (#16233)"

This reverts commit 13816dd4.
Apart from enabling transformer for MKL-DNN

* Revert "- MKL-DNN pooling updated to set_prim_desc"

This reverts commit c63f6b20.

Conflicts:
	paddle/fluid/operators/mkldnn/concat_mkldnn_op.cc

* Revert "[MKL-DNN] MKL-DNN specific Tensor modification (#15429)"

test=develop

This reverts commit dec9cf53.

* - concat compilation fix

- lint

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- Lint fixes

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- Lint fixes

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- Fix Transpose MKLDNN op

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* fix threaded executor bug
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* change the order of class member
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* Fix Travis CI
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* modify the interface of Pass::Allay
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* Polish code
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* Fix Travis CI
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* fix Pass::Apply interface
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* Fix Travis CI
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add include headers to fix travis-ci
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* fix cdn issue, test=develop

* fix memory optimize bugs, test=develop

* fix memory optimize bugs, test=develop

* remove add/sub_2 op, test=develop

* disable memory_optimize by default, test=develop

* disable inplace activation in python, test=develop

* fix unittests, test=develop

* fix unittests, test=develop

* bug-fix, test=develop

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* test fix fetch bar place for ce

* fix ps mode dist train in develop test=develop

* fix style check test=develop

* update test=develop

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fix ctest eager deletion disable bug
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refine gc code
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* refine parallelExecutor
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* Polish op_handle
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* Remove unnecessary op_handle
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* Fix Travis CI
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* Fix fetch bug
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* Remove WaitInputVarGenerated

* Fix OpHandleBase::Run
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* debug
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* use origin fetch_op_handle
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* Revert op_handle_base.cc
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* Polish code
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* Fix OpHandleBase::Run
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* code refine

* test CI and CE
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* fix OpHandle::Run
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* refine AllReduceOpHandle
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* Polish code
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* refine fused_all_reduce_op

* add unit test in test_parallel_executor_seresnext
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modify allocator strategy
remove changes of legacy buddy_allocator
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* Add enabling quantization

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* remove unused (here) function

support change input size

* fuse all_reduce
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* add fuse_parameter_groups_size
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* Polish code
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* Fix travis-ci
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* Add SetGroupAccordingToLayers and SetGroupAccordingToGroupSize
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* Add SetGroupAccordingToMemorySize
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* fix multi_devices_graph
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* reset params_grads
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* Polish code
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* wip allreduce in op

* wip

* wip

* wip

* wip adding test

* wip for conflict with mp mode

* fix tests test=develop

* fix cpu build test=develop

* fix travis clang format test=develop

* fix cpu build test=develop

* update api.spec test=develop

* delete comment test=develop

* fix cpplint test=develop

* fix test=develop

* follow comment test=develop

* add file test=develop

* fix build test=develop

* update test=develop

* to be compatible with sync_bn, and fix mp mode in develop test=develop

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* - Fix to crash of Transformer when mkldnn is to be used

Desc: TensorCopy was not setting MKLDNN primitive descriptor when layout was to be kMKLDNN

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* - Enable transformer for mkl-dnn

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* - Compilation fix

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* - Removed manual selection of MKL-DNN ops to be used in Transformer test

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* Add cpu_quantize_placement_pass for C-API quantization

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* added a comment on required pass attributes

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* Add cpu_quantize_pass for C-API quantization

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* add cpu_quantize_pass test

* fix lint: add include memory unorderd_map and unordered_set

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* fuse_relu 1

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* tuned 2 without squash

* fixes

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* remove unused vars

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* refactored

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* fix lint c-style cast -> C++ style cast

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* remove QuantMax and c style casts

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* last usage of QuantMax removed

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* Fix Analysis Predictor UT

Check if memory_optimize_pass has already been added
to the analysis config before adding a new one, so
that it is not added multiple times.
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* change map to unordered_map

fix the forgotten part of cpu_quantize_pass_tester.cc

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* removed quantized attribute

* fixed cpu_quantize_pass_tester and op attr comments

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* removed redundant line

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* removed gmock

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* fix after merge