GitLab

* [sync BN]

support non-uniform batch size across process group.

TODO: test should be added once cleaned up.

* updating unit tests

* new unit tests for different inputs

* cleaning

* Persistent group batchnorm added

Added persistent grouped batch norm for performance run on strong scaling case:
currently only supporting:

  1. nhwc layout
  2. fp16
  3. synchronization only within a node!

Environment variable is used to tune LAUNCH_MARGIN that limits the CTAs usage
by the persistent kernel.

Documentation and examples will follow.

* updating type().scalarType() to scalar_type()

* moving launch margin to be defined at layer creation, adding a knob cap max ctas per sm

* fixing the cta computation

* review comment:

set device_id through cudaGetDevice()
move cudaMemset to cudaMemsetAsync
updated __threadfence() to __threadfence_system() inter device write

Added kernel to support sync BN for channel last tensor

* [syncBN]
  added syncBN in native pure python apex
  added fused cuda kernels used for sync BN. Using welford for mean/var
    optional installation using 'python setup.py install --cuda_ext'
  added unit test with side to side comparison between apex sync BN with
    PyTorch BN. Notice that for pytorch BN implementation, because of
    numerical issue for mean/var, the output will be slightly off.

* [syncBN PR]
  added fp16 support
  addressing review comments on:
    1. updating last pow 2
    2. look for import error when importing syncBN kernel

* [syncBN PR]
  added convert function to insert SyncBatchNorm
  refactored some kernel code

* fixing type issue (fp16/fp32/fp64)
added Kahan summation
editing unit test to use pytorch primitive ops with double, passing reasonable tests now

* updating tensor creation calls

* fixing the all_reduce contiguous tensor

* transposed all reduce results

* [syncBN]
support fp16 input & fp32 layer for apex fp16
partially fixing launch configs
enabling imagenet example to run with --sync_bn

* [syncBN PR]
Documentation added

* adjusting README

* adjusting again

* added some doc to imagenet example

* [syncBN]
  warp-level reduction
  bug fix: warp reduction logic updated. check for dummy element to avoid nan.
  improved launch config for better reduction kernels. Further improvements
would be to increase grid size.

* [syncBN]
  fixing undefined behavior in __shfl_down_sync from divergent threads in warp
reduction.
  changing at::native::empty to at::empty (upstream comments)