Use DistributedSampler when running with custom accelerator

[ajtritt]

What does this PR do?

Fixes #7813.

This only fixes the problem for DDDPlugin. I suspect the same problem exists for other distributed data parallel plugins, but I'm not familiar enough with those training types to verify that.

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[pep8speaks]

Hello @ajtritt! Thanks for updating this PR.

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2021-06-18 09:47:48 UTC

[codecov]

Codecov Report

Merging #7814 (f240818) into master (599d6db) will decrease coverage by 5%.
The diff coverage is 100%.

@@           Coverage Diff           @@
##           master   #7814    +/-   ##
=======================================
- Coverage      92%     87%    -5%     
=======================================
  Files         207     207            
  Lines       13484   13489     +5     
=======================================
- Hits        12354   11719   -635     
- Misses       1130    1770   +640     

[tchaton]

LGTM ! Nice catch !

[awaelchli]

we probably have to add the same fix to select_precision_plugin()?

[tchaton]

Dear @ajtritt,

The tests are failing. Do you need help resolving them ?

Best,
T.C

[awaelchli]

@ajtritt Thanks for looking into this. Are you interested in sending an equivalent fix for the precision plugin logic for a custom accelerator?