1. In file "kvstore_dist_server.py"

Change

419      // TODO(mli) try to remove this CopyFrom
420     response.vals.CopyFrom(static_cast<const float*>(stored.data().dptr_), len);

to

response.vals = ps::SArray<float>(stored.data().dptr<float>(), len, false);

In a vgg16 training with two distribute machines (total 8 gpus), it can accelerate 20 samples/sec.
Is this method correct?

2. In file "kvstore_dist.py"

Delete the line 275 "send_buf.WaitToWrite();", can accelerate the speed with kvstore='sync_device' or 'local'.
In profile, I can find this WaitToWrite cause all the push locked until the whole backward finished.
Is this WaitToWrite necessary?