vso-hash-cuda

Golang implementation of the BuildXL paged hash function (a.k.a. VSO-Hash)

See https://github.com/microsoft/BuildXL/blob/master/Documentation/Specs/PagedHash.md for more information about the function in general.

See https://github.com/peterebden/vso-hash for a CPU-based implementation.

Building

I (unsurprisingly) recommend building this with Please. It should be as simple as ./pleasew run //cmd:go_main to run the Go version of it. You will obviously have to have the CUDA tools installed (nvidia-cuda-toolkit etc) for anything to work.

If you want to build it using go build, you will have to manually invoke nvcc first:

nvcc --shared --compiler-options='-fPIC' -o libsha256.so sha256.cu
go build

Unfortunately go test doesn't work. It's also unlikely to ever be go get-able since there's no way of scripting that nvcc invocation. See the link above for more details on plz which can do that!

Notes

Currently this is (sadly) losing to the CPU version in terms of performance, although does have the advantage that most of your CPU cores are still available for doing other things. Most likely it is limited by something else at this point, e.g. CPU, memory bandwidth or general implementation tomfoolery. Since it's mostly a learning project at the moment I'm not highly motivated to dig into the details of exactly what is going wrong.

The Sequential0 test is not working; no doubt there is some silly edge case that isn't being handled correctly (I've already fixed one of these but when it didn't immediately fix the problem I gave up).

The contents of sha256.cu are heavily based on https://github.com/B-Con/crypto-algorithms/blob/master/sha256.c by Brad Conte.