@mratsim was curious about how Rust's parallelism libraries would fare on the task-parallel/data-parallel performance front, so I rolled out a quick Rayon port of some of Weave's parallel benchmarks.
You can build & run a benchmark using cargo run --release --bin <name> <args>.
For example, to run the dfs microbenchmark with depth 10 and breadth 9, you
would do cargo run --release --bin dfs 10 9.
Alternatively, since cargo run's design is not so friendly to performance
analysis tools like perf or GNU time, you may prefer to build everything with
cargo build --release --all, then run the generated binaries located in
./target/release/<name> yourself as a separate step.
By default, the benchmarks try to replicate the behavior of the Weave benchmark
as closely as possible, even if that means using a Rayon code path that is
well-known to have suboptimal performance and can be easily replaced with a more
performant alternative. To unleash Rayon's full potential, pass the
--features idiomatic flag to the above cargo build or cargo run commands.
For example, to build all benchmarks with idiomatic use of Rayon, you would
do cargo build --release --features idiomatic --all.
On my machine, a well-tuned Rayon program has performance that's roughly on par with the Weave version. This is actually a pretty impressive result for Weave given the difficult constraints which this library currently operates under (strict Cilk-like task spawning model without optimized primitives for binary fork-join or data parallelism, message-passing based implementation, fine-grained task synchronization, ...).