GitLab

* First commit to add flash attention 2 for GPT-2

* more improvements

* Make GPT2 pass tests and fixed Decison Transformers copies

* Fixed missing arg

* fix copies

* Added expected speedup

* Update src/transformers/models/gpt2/modeling_gpt2.py
Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

* Update src/transformers/models/gpt2/modeling_gpt2.py
Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

* Update src/transformers/models/gpt2/modeling_gpt2.py
Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

* Added test

* Fixed attn attribute

* Update docs/source/en/model_doc/gpt2.md
Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

* Update docs/source/en/model_doc/gpt2.md
Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>

* Update Decision transformer attentions

* More updates

* Passing tests

* Fix copies

* Fix copies part 2

* Decision transformer updates

* Update src/transformers/models/gpt2/modeling_gpt2.py
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>

* Fix copies

* Decision transformer not supporting flash attn

* Addressed comments

* Addressed comments

* Addressed comments

---------
Co-authored-by: Arthur <48595927+ArthurZucker@users.noreply.github.com>
Co-authored-by: amyeroberts <22614925+amyeroberts@users.noreply.github.com>