GitLab

* [shardformer/sequence parallel] Support sequence parallel for gpt2 (#4384)

* [sequence parallel] add sequence parallel linear col/row support (#4336)

* add sequence parallel linear col/row support

* add annotation

* add annotation

* add support for gpt2 fused qkv linear layer

* support sequence parallel in GPT2

* add docstring and note

* add requirments

* remove unused flash-attb

* modify flash attn test

* modify flash attn setting

* modify flash attn code

* add assert before divide, rename forward function

* [shardformer/test] fix gpt2 test with seq-parallel

* [shardformer/sequence parallel] Overlap input gather and grad computation during col backward (#4401)

* overlap gather input / grad computing during col backward

* modify test for overlap

* simplify code

* fix code and modify cuda stream synchronize

* [shardformer/sequence parallel] polish code