Kernels flash attn (#39474)
* use partial to wrap around `transformers` utils!
* try to refactor?
* revert one wrong change
* just a nit
* push
* reverter watever was wrong!
* some nits
* fixes when there is no attention mask
* bring the licence back
* some fixes
* nit
* style
* remove prints
* correct dtype
* fa flags for testing
* update
* use paged attention if requested!
* updates
* a clone was needed, not sure why
* automatically create cu seq lens when input is flash, this at least makes sure layers don't re-compute
* simplify and improve?
* flash attention is kinda broken on recent cuda version so allow the opportunity to use something else
* fix!
* protect kernels import
* update
* properly parse generation config being passed
* revert and update
* add two tests
* some fixes
* fix test FA2
* takes comment into account
* fixup
* revert changes
* revert the clone, it is only needed because the metal kernel is not doing it?
* [docs] update attention implementation and cache docs (#39547)
* update docs
* Apply suggestions from code review
Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>
* applu suggestions
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Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>
* fix mps on our side for now
* Update src/transformers/integrations/flash_paged.py
* no qa
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Co-authored-by: Vasqu <antonprogamer@gmail.com>
Co-authored-by: Raushan Turganbay <raushan@huggingface.co>
Co-authored-by: Steven Liu <59462357+stevhliu@users.noreply.github.com>
