Add invalidations script

[charleskawczynski]

For now, this script grabs invalidations and plots the number (and percentage) of children per method invalidation.

It seems that DiffEq.jl's Base.mapreduce_empty is triggering ~1k invalidations (almost 50% of all invalidations). It is recommended to tackle expensive invalidations before moving on to improving inferrability / profile-guided despecialization to improve latency.

[charleskawczynski]

cc @jakebolewski / @simonbyrne, this could be affecting ClimaCore, too, since we have many overlapping deps.

[charleskawczynski]

bors r+

[jakebolewski]

I'm not sure what we can do if it is caused by a dependency?

[jakebolewski]

There are some patched diffeq support functions that are no longer necessary now that we support FieldVector's, if we get rid of some of those and only support Diffeq operations on FieldVectors and not fields that might help.

[bors]

Build succeeded:

• buildkite/turbulenceconvection-ci
• docbuild
• format

[charleskawczynski]

This was fixed by DiiffEqBase.jl's 723 🎉

[ChrisRackauckas]

How did you get the number of invalidations to see the priority? I want to run that on all of DiffEq and just do a bunch of quick PRs like this.

[charleskawczynski]

How did you get the number of invalidations to see the priority? I want to run that on all of DiffEq and just do a bunch of quick PRs like this.

@ChrisRackauckas, Everything is actually in this PR, here's a short pseudo-code summary:

# From: https://timholy.github.io/SnoopCompile.jl/stable/snoopr/
using SnoopCompileCore
invalidations = @snoopr begin
    # load packages & do representative work
end;

import SnoopCompile
trees = SnoopCompile.invalidation_trees(invalidations);

@show length(SnoopCompile.uinvalidated(invalidations)) # show total invalidations

show(trees[end]) # show the most invalidated method

# Count number of children (number of invalidations per invalidated method)
n_invalidations = map(trees) do methinvs
    SnoopCompile.countchildren(methinvs)
end

import Plots
Plots.plot(
    1:length(trees),
    n_invalidations;
    markershape = :circle,
    xlabel = "i-th method invalidation",
    label = "Number of children per method invalidations",
)