Channel Examples

[hunhoffe]

Channels are a key abstraction of mlir-air, but there are few examples for how to use them. This issue is a place to discuss which examples are needed to show how channels work, and which of those examples are implemented.

Functional Examples

• [x] Herd2Herd (core in herd0 to core in herd1 using L1 data) https://github.com/Xilinx/mlir-air/pull/636
• [x] Channel bundling (using sizes/indices) https://github.com/Xilinx/mlir-air/pull/642
• [x] Hierarchical (launch -> segment -> herd) https://github.com/Xilinx/mlir-air/pull/661
• [x] Broadcast to multiple workers in same herd https://github.com/Xilinx/mlir-air/pull/688 https://github.com/Xilinx/mlir-air/issues/689
• [x] Broadcast to multiple herds https://github.com/Xilinx/mlir-air/pull/688 https://github.com/Xilinx/mlir-air/issues/689
• [x] Intra-Herd Communication: Worker to worker (https://github.com/Xilinx/mlir-air/pull/653, https://github.com/Xilinx/mlir-air/pull/697, https://github.com/Xilinx/mlir-air/pull/697, https://github.com/Xilinx/mlir-air/issues/660)
• [ ] Overly simplistic sliding window example - does not yet support data streaming https://github.com/Xilinx/mlir-air/pull/704

Failing Examples

• [x] Intra-Herd Communication: Worker to self (https://github.com/Xilinx/mlir-air/issues/654, https://github.com/Xilinx/mlir-air/pull/653, https://github.com/Xilinx/mlir-air/pull/668, https://github.com/Xilinx/mlir-air/issues/666)
• [x] Create basic example with two segments (something evens simpler that doesn't use channels, because this is largely untested) (https://github.com/Xilinx/mlir-air/pull/663)
• [x] L1-L1 (worker to worker, where the workers are in herds in the different segments) (https://github.com/Xilinx/mlir-air/pull/663) (https://github.com/Xilinx/mlir-air/issues/665)

Not-Yet Implemented Examples

• [ ] L2-L2 (from segment to segment directly) [Deferring on this indefinitely, until multiple segments are supported] (https://github.com/Xilinx/mlir-air/issues/665)

Discussion Topics

Is Launch2Launch Desirable?

• Some trouble creating multiple launches, so this may be a little early in terms of creating a launch2launch channel communication (see issue https://github.com/Xilinx/mlir-air/issues/627)
• What information would you need to scheduling launches in order to do this?

Synchronous vs Asynchronous

• Might one day be good to have some examples where the user explicitly sets async tokens on channel operations, but this capability isn't implemented yet in the air dependency pass.

Placement

• An example doing something specific with channels based on placement of resources?

What is the best way to implement a sliding window of data with channels?

• Do we need some sort of peek() functionality?