performance tests: define a baseline

[pgte]

I think we should define some performance requirements for bitswap (like, for example: "for 10 bitswaps exchanging 1000 blocks between themselves, they must execute this in X seconds or less"), and then apply these to the already existing test/benchmarks.

This is almost done (test/benchmarks already can be parametrised to spawn a network of x nodes exchanging y blocks), so I think this is just a matter of defining the baseline to:

a) prevent performance regressions
b) incorporate improvements

@victorbjelkholm @vmx Thoughts on this?

[victorb]

Sounds about right. One thing that is needed for the baseline is the specs of the machine where the benchmarks are run, so we can still ~ follow the baseline on less/more powerful machines.

[pgte]

@victorbjelkholm Should the new CI infra-structure be able to handle this stability, or are we looking into some variance we need to deal with?

[victorb]

My thinking is that we should probably use some standard specs from an average laptop as the baseline, and we can spin up CI workers that are close to that.

[vmx]

Sounds good. Couchbase has a nice dashboard to easily spot regressions between builds: http://showfast.sc.couchbase.com/. Having something like that would be great. I know that's a separate discussion, but I thought this is a good place to bring it up.