* Revert "Revert "[PsCore] optimize performance of large kv (#32535)" (#32599)"

This reverts commit 809ac036.

* brpc dep

Reduce the time cost for the elementwise_add test case (#32628)

* add alltoall api, test=develop

* update 2.0 public api in nn

* replace Chinese character cause error in ci;synchronization with pr:#32588 to avoid 'ascii' codec in python2

* numbers used in paddle.nn.functional.norm but not imported

Co-authored-by: NXiaoguangHu <46782768+XiaoguangHu01@users.noreply.github.com>

* edit paddle.save/load API

* Update io.py

edit doc

* delete cpython-37.pyc

* Update io.py

edit doc

* Update io.py

recommit

* Update io.py

recommit

* Update io.py

recommit

* Update io.py

recommit

* clear 'BasicEngine' when an exception occurs in the backward.

* deal with conflict.

* deal with conflict.

* jit.save/load support function.

* delete unnittest test_jit_load_model_incomplete.

* edit code according to CI

* Modify the documentation.

* add note to doc.

* fixed docs.

* Fixed docs. test=document_fix

code bak.

fixed docs. test=document_fix

* Revert to previous version of python/paddle/fluid/backward.py

* fixed bugs.

* test=document_fix. Fixed examples.

* fix cross_entropy calculation error

* add unittest and fix static

* Support list and tuple for parameters of layer_norm, multiprocess_reader, DatasetFolder and ImageFolder.

* add unittest for layer_norm.

* add require gpu for example.

This reverts commit 4b7242b0.

* fix amp bug

* fix name of wordsize

* add sendrecv, test=develop

* optimize pull sparse

* optimize pull sparse

* change macro

* format

* fix bn docs

* fix unittest

A follow up PR of #32420, we changed the doc of python/paddle/fluid/layers/tensor.py in that PR and we are changing python/paddle/tensor/creation.py in this PR.

* Modified params of some APIs to support tuple and list.

* fixed bug.

* Modified the return value of tensor.grad from numpy as tensor.

* Modify unittests.

* fixed bugs.

* Add warning info for x.grad

* fixed unittests which used x.grad

* fixed bug.

* fix dataloader exit error if user exit program when dataloader is still iterating. test=develop

* Unset ReserveSpace for inference program.

* Support training from an inference program.

* change prepend to append

* fix ut

* add testcase

* fix ut

* fix test_custom_relu_model

* fix model parallel

* rm parallel_help.py

* add embedding

* support backward return None.

* edit unittest.

* edit code according to CI

* Improve error information

* skip op has no fp16 kernel

* add ut

* add norm_by_times param to ctc_loss

* fix doc,test=develop