Example should have performance numbers and comparisons

[alexanderkjeldaas]

I'm doing some benchmarking, and while this might be apples to oranges,

1. Invoking quickjs as a wasmtime precompiled using --eval console.log('hello world') 1000 times takes approx 7-8s
2. Invoking the hello-world.js embedding in the example 1000 times takes approx 80s or maybe 10x as much time.

time for x in `seq 1 1000`; do wasmtime --allow-precompiled  quickcheck.cwasm --eval "console.log('hello world')"; done

real	0m7.849s
user	0m3.077s
sys	0m6.752s

$ time for x in `seq 1 1000`; do ./target/release/wasmtime-test > /dev/null; done

real	1m21.672s
user	0m45.470s
sys	0m38.263s

Using https://gitlab.com/api/v4/projects/47807501/packages/generic/js_interpreters/0.0.1/cweb_quickcheck.wasm for the example.

It would be good to understand better what performance we can expect and how to benchmark against other options.

[guybedford]

Make sure to check with the --enableAot / enableAot option for ComponentizeJS here which uses https://github.com/bytecodealliance/weval.

Benchmarking for StarlingMonkey in general is tracking in bytecodealliance/StarlingMonkey#102.

[tanishiking]

Out of curiosity, I tried running a similar script with enableAOT: true/false, and it seems that executing a similar script with enableAOT: true makes it slower 🤔 (Sorry if I misunderstand something).

# becnh.sh
for x in $(seq 1 1000)
do
  ./target/release/wasmtime-test > /dev/null
done

# on examples/hello-world/host

# enableAOT: true
$ /usr/bin/time ./bench.sh
818.09 real       760.74 user        43.66 sys

# enableAOT: false
$ /usr/bin/time ./bench.sh
315.31 real       293.17 user        27.95 sys

[guybedford]

It depends on the exact workload whether the AOT flag improves performance or not. It's also worth testing on precompiled binaries since AOT sources are larger so will have a longer compile time in Wasmtime.

[tanishiking]

That makes sense, hello world app would be too small to benefit from weval 👍