tree 3661e1de30a129106677a52242c889aafed4d731
parent ac8f6785d341574d9f27ced411f5f46d5e1a49f6
author A. Unique TensorFlower <gardener@tensorflow.org> 1610602530 -0800
committer TensorFlower Gardener <gardener@tensorflow.org> 1610602927 -0800

Control dependency flowing between devices should have a higher priority virtual channel than data flows, otherwise there is a risk of control transfer getting stuck behind a large data transfer. Current channel device implementation is simple, it doesn't model such prioritization.

Instead of adding complexity to channel device, tf-sim could let control deps bypass channel device and (magically) flow across devices in zero time. Control deps are small, latency dominated transfers. Channel devices are only good at modeling BW bound transfers, so bypassing channel device for control deps should not be so bad.

PiperOrigin-RevId: 351727352
Change-Id: Ibe20b9018427e30cffe9e7fc1cb3713ebe47510b