3 ms·

Is there a benchmark available where you compared Lua and wasmtime against your interpreter? It would be interesting for Lua and wasmtime developers to chime in

Is there a benchmark available where you compared Lua and wasmtime against your interpreter? It would be interesting for Lua and wasmtime developers to chime in on why the world switch overhead is higher and whether there exist configuration settings or APIs that eliminate the overhead for your use case. I'm curious if there is any fundamental reason why they have to be slower and I suspect the answer is "no".

fwsgonzo 3y ago
Binary translated libriscv vs LuaJIT: https://gist.github.com/fwsGonzo/9132f0ef7d3f009baa5b222eedf392da https://gist.github.com/fwsGonzo/9132f0ef7d3f009baa5b222eedf... Interpreted libriscv vs LuaJIT: https://gist.github.com/fwsGonzo/1af5b2a9b4f38c1f3d3074d78acdf609 https://gist.github.com/fwsGonzo/1af5b2a9b4f38c1f3d3074d78ac... libriscv vs. Luau: https://gist.github.com/fwsGonzo/5ac8f4d8ca84e97b0c527aec76a86fe9 https://gist.github.com/fwsGonzo/5ac8f4d8ca84e97b0c527aec76a... wasmtime: https://medium.com/@fwsgonzo/using-c-as-a-scripting-language-part-10-ad7dd7e4325d https://medium.com/@fwsgonzo/using-c-as-a-scripting-language... You're probably right that things can be improved. But my implementation has the aforementioned latencies right now. For the benchmarks I did my best writing good Lua, but I am not a pro. Call overhead is also subtracted out of every benchmark after call overhead is measured. So that extra overhead is a permanent feature of these implementations. I also noticed that most of my script functions have at least ~3-4 arguments, which seems like it would be quite costly. Just look at the 8x arg benchmark and divide by 2, I guess. Another 100ns right there. Baseline 150ns on a micro benchmark is going to become at least a microsecond in prod when everything is random and semi-cold.
- stefanha 3y ago
  Cool, thanks for sharing this information! I'm not a Lua or wasmtime developer, but I hope to learn from whatever discussion follows.

fwsgonzo 3y ago

Binary translated libriscv vs LuaJIT: https://gist.github.com/fwsGonzo/9132f0ef7d3f009baa5b222eedf392da https://gist.github.com/fwsGonzo/9132f0ef7d3f009baa5b222eedf... Interpreted libriscv vs LuaJIT: https://gist.github.com/fwsGonzo/1af5b2a9b4f38c1f3d3074d78acdf609 https://gist.github.com/fwsGonzo/1af5b2a9b4f38c1f3d3074d78ac... libriscv vs. Luau: https://gist.github.com/fwsGonzo/5ac8f4d8ca84e97b0c527aec76a86fe9 https://gist.github.com/fwsGonzo/5ac8f4d8ca84e97b0c527aec76a... wasmtime: https://medium.com/@fwsgonzo/using-c-as-a-scripting-language-part-10-ad7dd7e4325d https://medium.com/@fwsgonzo/using-c-as-a-scripting-language... You're probably right that things can be improved. But my implementation has the aforementioned latencies right now. For the benchmarks I did my best writing good Lua, but I am not a pro. Call overhead is also subtracted out of every benchmark after call overhead is measured. So that extra overhead is a permanent feature of these implementations. I also noticed that most of my script functions have at least ~3-4 arguments, which seems like it would be quite costly. Just look at the 8x arg benchmark and divide by 2, I guess. Another 100ns right there. Baseline 150ns on a micro benchmark is going to become at least a microsecond in prod when everything is random and semi-cold.

stefanha 3y ago
Cool, thanks for sharing this information! I'm not a Lua or wasmtime developer, but I hope to learn from whatever discussion follows.