optimize dual pp overlap

[phlrain]

PR Category

Distributed Strategy

PR Types

Improvements

Description

优化dual pp 的逻辑，使得第二组send/recv 能够在attention back阶段尽早拉起
pcard-91067

[paddle-bot]

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[codecov-commenter]

Codecov Report

❌ Patch coverage is 26.31579% with 14 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (develop@2a78ac9). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
...addle/distributed/fleet/meta_parallel/dualpipev.py	7.14%	13 Missing ⚠️
...stributed/fleet/meta_parallel/zero_bubble_utils.py	80.00%	1 Missing ⚠️

❌ Your patch status has failed because the patch coverage (26.31%) is below the target coverage (90.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             develop   #74527   +/-   ##
==========================================
  Coverage           ?   26.31%           
==========================================
  Files              ?        2           
  Lines              ?       19           
  Branches           ?        0           
==========================================
  Hits               ?        5           
  Misses             ?       14           
  Partials           ?        0           

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[zhiqiu]

LGTM