Exponential decay of the weight of task loss (#27508)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/27508
Implemented a simple exponential decay of the weight of lr loss function, with a lower bound.
Test Plan:
buck test //caffe2/caffe2/fb/dper/layer_models/tests:mtml_test -- test_task_weight_decay
https://our.intern.facebook.com/intern/testinfra/testrun/3377699729136308
canary: f140103452
Reviewed By: chenshouyuan
Differential Revision: D17524101
fbshipit-source-id: 9a653e21a4ecb74dfc4ac949c9e3388f36ef3a20
