lighthouse/.github
Michael Sproul f77e3bc0ad Add maxperf build profile (#3608)
## Proposed Changes

Add a new Cargo compilation profile called `maxperf` which enables more aggressive compiler optimisations at the expense of compilation time.

Some rough initial benchmarks show that this can provide up to a 25% reduction to run time for CPU bound tasks like block processing: https://docs.google.com/spreadsheets/d/15jHuZe7lLHhZq9Nw8kc6EL0Qh_N_YAYqkW2NQ_Afmtk/edit

The numbers in that spreadsheet compare the `consensus-context` branch from #3604 to the same branch compiled with the `maxperf` profile using:

```
PROFILE=maxperf make install-lcli
```

## Additional Info

The downsides of the maxperf profile are:

- It increases compile times substantially, which will particularly impact low-spec hardware. Compiling `lcli` is about 3x slower. Compiling Lighthouse is about 5x slower on my 5950X: 17m 38s rather than 3m 28s.

As a result I think we should not enable this everywhere by default.

- **Option 1**: enable by default for our released binaries. This gives the majority of users the fastest version of `lighthouse` possible, at the expense of slowing down our release CI. Source builds will continue to use the default `release` profile unless users opt-in to `maxperf`.
- **Option 2**: enable by default for source builds. This gives users building from source an edge, but makes them pay for it with compilation time. 

I think I would prefer Option 1. I'll try doing some benchmarking to see how long a maxperf build of Lighthouse would take on GitHub actions.

Credit to Nicholas Nethercote for documenting these options in the Rust Performance Book: https://nnethercote.github.io/perf-book/build-configuration.html.
2022-09-29 06:13:33 +00:00
..
custom Add merge support to simulator (#3292) 2022-07-18 23:15:40 +00:00
workflows Add maxperf build profile (#3608) 2022-09-29 06:13:33 +00:00
ISSUE_TEMPLATE.md Remove links to old master branch (#2190) 2021-02-11 06:06:54 +00:00
PULL_REQUEST_TEMPLATE.md Add PR and issue templates 2018-10-14 14:51:59 +11:00