* update the demo code and the doc of varbase.backward.

* update the doc of the fake interface `paddle.fluid.Variable`.

* remove BackwardStrategy.

add collective op for cpu using gloo and paddle.distributed.* apis

* Add mechanism for blocking oneDNN cache clearing

* Review changes and Add thread guards

* support Baidu AI Accelerator
  * test=kunlun

* minor
 * test=kunlun

* support xpu op in separate file
 * test=kunlun

* update XPU error message and remove duplicated code

 * test=kunlun

* minor
 * test=kunlun

* minor
 * test=kunlun

* print user-friendly error message

* adjust error sumary

* Change use_quantizer attribute name and data type

* Fix problem with setting attribute

* Add changes due to review

* Small change in function

* Restore use_quantizer attr for compatibility

* add flags_call_stack_level

* update

* refine code

* fix trt plugin registry without trt lib

* support trt4

* refine code style

* Add oneDNN fusion_gru kernel and fix fc+gru pass
test=develop

* Formatting changes
test=develop

* Lint fixes
test=develop

* Add memory::format_tag::any to GRU weights
test=develop

* Fix build with CUDA

* Fix build with CUDA v2

* cunn8 support
test=develop

* fix ci error
test=develop

* develop dynamic shape serilization

* add test param for gelu

* fix bugs

* delete redundant comments

* debug

* fix conflict. test=develop

* fix bug. test=develop

* add trt dynamic shape serialized support

* fix ernie serialized bug
test=develop

* fix codestyle
test=develop

* fix bug
test=develop

* fix bug.test=develop

* modify cmakelist test=develop

* fix bug
test=develop

* fix error message.  test=develop

* fix trt register plugin based on pr#25003

* add trt dynload

* fix deserialization bug of not finding plugin registration

* refine code style

* recover engine key in tensorrt_subgraph_pass

* for ci coverage

* add unittest for deserialization
Co-authored-by: Nhaozech <chenhaoze94@gmail.com>

* refine error stack format

* polish compile traceback format

* polish detail format

* unified signal error format

* refine signal error message

* simplify buffered reader to improve DataLoader performance

* fix 22 failed unittests

* fix cuda pinned context condition

* fix test_reader_reset failed

* fix two failed unittests

* change unittest place

* polish error messaage

* polish cast op GetExpecctedKernelType

* remove debug info in unittest

* Added DNNL cache management for DyGraph

* move FLAGS_use_mkldnn to more general CMakeLists, getu use of the flag in ClearGradients

* missing file

* Fixes after review

* Bringing back original idea of place for 'use_mkldnn' flag to be accessible from platform nad imperative.

* Removed duplicate and added docs

* Fixes for CI

test=develop

* polish install error hint msg, test=develop

* fix variable error, test=develop

* polish hint messgae again

* add bilateral slice op

* Refine PADDLE_ENFORCE in paddle/fluid/platform
test=develop

* fix softmax_with_cross_entropy cuda kernel overflow bug, test=develop

* replace old macro & for condition, test=develop

* polish details, test=develop

remove useless property

test=develop

* refine PADDLE_ENFORCE
test=develop

* fix PADDLE_ENFORCE and refine the description
test=develop

* refactor dynamic dso search func, test=develop

* polish details, test=develop

* polish detail based review comments, test=develop

* revert string type change, test=develop

* add default cudnn lib path, test=develop

* change default path in func, test=develop

* move to linux branch, test=develop

* fix var error in other plat, test=develop

* Refactor of conv fp32 oneDNN operator
test=develop

* Formatting fix
test=develop

* Return Enforces
test=develop

* GetWeights improvements
test=develop

* remove disable profiler_test on win32

* add log

* enlarge the elapsed time

* Revert "add log"

test=develop

* Start implementing int8 eltwise add

test=develop

* - Fix to Michal PR

* - Fix

test=develop

* - Lint fixes

test=develop

* - Added checking if elementwise_mul can be used

test=develop

* - Added attribs to skip_attrs_set

test=develop

* - Improved broadcasting

test=develop

- fixes to compilation

- fix

- fix

- Lint fixes

test=develop

* - removed redundant condition

test=develop
Co-authored-by: NMichal Gallus <michal.gallus@intel.com>

* Add a StatValue class in the backend to represent a stat.
* Add a singleton StatRegistry to maintain the collection of stats.
* For the sake of code neatness, we only support type of int and float, which can cover most of the scenarios.