ocaml-multicore VS weave

1. Domains are the unit of parallelism. A domain is essentially an OS thread with a bunch of extra runtime book-keeping data. You can use Domain.spawn (https://github.com/ocaml-multicore/ocaml-multicore/blob/5.00...) to spawn off a new domain which will run the supplied function and terminate when it finishes. This is heavyweight though, domains are expected to be long-running.

2. Domainslib is the library developed alongside multicore to aid users in exploiting parallelism. It supports nested parallelism and is pretty highly optimised (https://github.com/ocaml-multicore/domainslib/pull/29 for some graphs/numbers). The domainslib repo has some good examples: https://github.com/ocaml-multicore/domainslib/tree/master/te...

3. We've not tested against other forms of parallelism. There isn't anything stopping you exploiting SIMD in addition to parallelism from domains.

4. No, we've not compared performance by OS.

5. No plans for the multicore team to look at accelerator integration at the moment.

For Algebraic Effects and Multicore OCaml specifically, I have this intro saved and they've been publishing regular updates here's October's. They have a paper linked from their repo's README but I don't remember the contents offhand.

Until recently Multicore OCaml was focused on deep handlers. The people working on the formalization of effects (either for program proofs or typed effects) were quite keen to have shallow handler integrated however. Thus, the effect module of the OCaml 5 preview contains both (see https://github.com/ocaml-multicore/ocaml-multicore/blob/5.00...) since September. I fear that non-academic literature has not followed this change (on the academic side, see https://dl.acm.org/doi/10.1145/3434314 for a program proofs point of view).

Yes, it's announcing that the next but one version, 5.0, will support multicore and effect handlers.

For what it's worth you can actually start using Multicore OCaml today, there are installation instructions on the wiki: https://github.com/ocaml-multicore/ocaml-multicore

ocaml-multicore/ocaml-multicore

Could you explain (in simple terms if possible) how the Multicore OCaml achieves a memory model which is much simpler on more efficient than in Java or C (mentioned at https://github.com/ocaml-multicore/ocaml-multicore/wiki)?

Didn't see any mentions of critical sections (mutexes) with C++ examples in the documentation ("Bounding Data Races in Space and Time"). I'm not sure I understand the comparisons the writers are presenting.

There are getting started instructions up on https://github.com/ocaml-multicore/ocaml-multicore

GPU drivers provide an event system:

- Cuda: https://github.com/mratsim/weave/issues/133

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Note: the Theoretical peak limit is hardcoded and used my previous machine i9-9980XE.

It maybe that your BLAS library is not named libopenblas.so, you can change that here: https://github.com/mratsim/laser/blob/master/benchmarks/thir...

Implementation is in this folder: https://github.com/mratsim/laser/tree/master/laser/primitive...

in particular, tiling, cache and register optimization: https://github.com/mratsim/laser/blob/master/laser/primitive...

AVX512 code generator: https://github.com/mratsim/laser/blob/master/laser/primitive...

And generic Scalar/SSE/AVX/AVX2/AVX512 microkernel generator (this is Nim macros to generate code at compile-time): https://github.com/mratsim/laser/blob/master/laser/primitive...

I'll come back later with details on how to use my custom HPC threadpool Weave instead of OpenMP (https://github.com/mratsim/weave/tree/master/benchmarks/matm...)

In my benchmarks, Nim is faster than Rust:

- multithreading runtime (i.e Rayon vs Weave https://github.com/mratsim/weave)

- Cryptography: https://hackmd.io/@gnark/eccbench#Pairing

- Scientific computing / matrix multiplication: https://github.com/bluss/matrixmultiply/issues/34#issuecomme...

There is no inherent reason why a Nim program would be slower than Rust.

If you're interested into diving into this I have reviewed solutions to cactus stacks / split stacks here https://github.com/mratsim/weave/blob/master/weave/memory/multithreaded_memory_management.md

[4] https://github.com/mratsim/weave