Effect of precompilation

[timholy]

https://discourse.julialang.org/t/suddenly-cannot-use-plots-package/42385

It would be sad to turn off precompilation entirely on older Julia versions, but unless you can track down the issue more specifically it's the easiest way to fix the problem.

[timholy]

Actually, is this even making use of the precompilation from SnoopCompileBot? I don't see any place where the source code says include("precompile_includer.jl"). @aminya, is this missing from the bot docs?

[daschw]

You're right, probably my fault.

[aminya]

Wait, this is strange. The bot should add include("precompile_includer.jl") automatically. I wonder it has failed to do so! 🤔

The log says it has done it! But it seems it is lost somewhere in the process. I need to test this offline and will get back to you.

https://github.com/JuliaPlots/Plots.jl/runs/825527122?check_suite_focus=true#step:7:10

[ Info: SnoopCompile will try to write  "include("precompile_includer.jl")" before end of the module in /home/runner/work/Plots.jl/Plots.jl/src/Plots.jl. Assume that the last `end` is the end of a module.

[timholy]

Also, seems unlikely to be the source of the crash reported in discourse, but do be careful about crashes in versions older than 1.4.2 (see the Julia PR linked from discourse).

Also, permit me a couple of SnoopCompile tutorials. First, let's see how well precompiation is working: after having added the include("precompile_includer.jl"), I get this:

julia> using SnoopCompileCore

julia> tinf = @snoopi tmin=0.01 (using Plots; p = plot(rand(10)); display(p))
33-element Array{Tuple{Float64,Core.MethodInstance},1}:
 (0.01029205322265625, MethodInstance for (::Core.var"#Type##kw")(::NamedTuple{(:libc, :compiler_abi),Tuple{Nothing,Pkg.BinaryPlatforms.CompilerABI}}, ::Type{Pkg.BinaryPlatforms.FreeBSD}, ::Symbol))
 (0.010421991348266602, MethodInstance for foreach(::Function, ::Array{Dict{Symbol,Any},1}, ::Array{Dict{Symbol,Any},1}))
 (0.010580062866210938, MethodInstance for warn_on_recipe_aliases!(::Plots.Plot{Plots.GRBackend}, ::Dict{Symbol,Any}, ::Symbol, ::Array{Float64,1}))
 (0.011501073837280273, MethodInstance for #any#651(::Function, ::typeof(any), ::Function, ::Array{Float64,1}))
 (0.011873960494995117, MethodInstance for get!(::Base.var"#137#138"{Set{Symbol}}, ::Dict{Symbol,Set{Symbol}}, ::Symbol))
 (0.01209402084350586, MethodInstance for resize_nthreads!(::Array{HTTP.URIs.RegexAndMatchData,1}, ::HTTP.URIs.RegexAndMatchData))
 (0.012480974197387695, MethodInstance for sum(::Array{Measures.Length{:mm,Float64},2}))
 (0.012552022933959961, MethodInstance for setindex!(::Dict{Any,Plots.Subplot}, ::Plots.Subplot{Plots.GRBackend}, ::Symbol))
 (0.012843132019042969, MethodInstance for setindex!(::Dict{Symbol,PlotThemes.PlotTheme}, ::PlotThemes.PlotTheme, ::Symbol))
 (0.014549016952514648, MethodInstance for setindex!(::Dict{Plots.Subplot,Any}, ::Dict{Symbol,Any}, ::Plots.Subplot{Plots.GRBackend}))
 (0.014793872833251953, MethodInstance for #gr_set_font#334(::Symbol, ::Symbol, ::RGB{FixedPointNumbers.Normed{UInt8,8}}, ::Float64, ::typeof(Plots.gr_set_font), ::Plots.Font, ::Plots.Subplot{Plots.GRBackend}))
 (0.015500068664550781, MethodInstance for #gr_set_font#334(::Symbol, ::Symbol, ::RGB{FixedPointNumbers.Normed{UInt8,8}}, ::Int64, ::typeof(Plots.gr_set_font), ::Plots.Font, ::Plots.Subplot{Plots.GRBackend}))
 (0.015724897384643555, MethodInstance for append!(::Array{RecipeData,1}, ::Array{RecipeData,1}))
 (0.016112089157104492, MethodInstance for _collect(::UnitRange{Int64}, ::Base.Iterators.Flatten{Tuple{Base.KeySet{Symbol,Dict{Symbol,Any}},Set{Symbol}}}, ::Base.HasEltype, ::Base.SizeUnknown))
 (0.016675949096679688, MethodInstance for _unsafe_copyto!(::Array{Plots.Subplot,1}, ::Int64, ::Array{Plots.Subplot{Plots.GRBackend},1}, ::Int64, ::Int64))
 (0.018754005432128906, MethodInstance for maximum(::Array{Measures.Length{:mm,Float64},1}))
 (0.019168853759765625, MethodInstance for _mapreduce_dim(::Function, ::Function, ::Base._InitialValue, ::Array{Measures.Length{:mm,Float64},2}, ::Int64))
 (0.019948959350585938, MethodInstance for mapreducedim!(::Function, ::Function, ::Array{Measures.Length{:mm,Float64},2}, ::Array{Measures.Length{:mm,Float64},2}))
 (0.020833969116210938, MethodInstance for get!(::Requires.var"#1#2", ::Dict{Base.PkgId,Array{Function,1}}, ::Base.PkgId))
 (0.022881031036376953, MethodInstance for *(::Int64, ::Array{Measures.Length{:mm,Float64},1}))
 (0.023634910583496094, MethodInstance for collect_to_with_first!(::Array{NTuple{4,Measures.Length{:mm,Float64}},2}, ::NTuple{4,Measures.Length{:mm,Float64}}, ::Base.Generator{Array{AbstractLayout,2},typeof(Plots._update_min_padding!)}, ::Int64))
 (0.024197101593017578, MethodInstance for Plots.GridLayout(::Int64, ::Vararg{Int64,N} where N))
 (0.025114059448242188, MethodInstance for apply_recipe(::Dict{Symbol,Any}, ::Array{Float64,1}))
 (0.03254199028015137, MethodInstance for warn_on_recipe_aliases!(::Plots.Plot{Plots.GRBackend}, ::Array{RecipeData,1}, ::Symbol, ::Array{Float64,1}))
 (0.03902387619018555, MethodInstance for resize_nthreads!(::Array{Dict{Sockets.IPAddr,HTTP.Servers.RateLimit},1}, ::Dict{Sockets.IPAddr,HTTP.Servers.RateLimit}))
 (0.04192495346069336, MethodInstance for +(::Array{Measures.Length{:mm,Float64},2}, ::Array{Measures.Length{:mm,Float64},2}))
 (0.056591033935546875, MethodInstance for _parse_colorant(::String))
 (0.0628499984741211, MethodInstance for showoff(::Array{Float64,1}, ::Symbol))
 (0.06933903694152832, MethodInstance for apply_recipe(::Dict{Symbol,Any}, ::Type{RecipesPipeline.SliceIt}, ::Nothing, ::Array{Float64,1}, ::Nothing))
 (0.07117319107055664, MethodInstance for recipe_pipeline!(::Plots.Plot{Plots.GRBackend}, ::Dict{Symbol,Any}, ::Tuple{Array{Float64,1}}))
 (0.09401392936706543, MethodInstance for (::Base.var"#maximum##kw")(::NamedTuple{(:dims,),Tuple{Int64}}, ::typeof(maximum), ::Array{Measures.Length{:mm,Float64},2}))
 (0.12085700035095215, MethodInstance for (::PlotUtils.var"#optimize_ticks##kw")(::NamedTuple{(:k_min, :k_max),Tuple{Int64,Int64}}, ::typeof(optimize_ticks), ::Float64, ::Float64))
 (0.17196011543273926, MethodInstance for resize_nthreads!(::Array{Dict{String,Set{HTTP.Cookies.Cookie}},1}, ::Dict{String,Set{HTTP.Cookies.Cookie}}))

This is a measure of stuff that isn't being precompiled because it's what's left over still needing inference. Several of those belong to dependent packages or base Julia. It's not bad at all, about 1.5s of remaining inference time. Main stragglers are in dependent packages like PlotUtils and RecipesPipeline, and it's possible that you could add precompilation to those packages and get them covered, too. (Also, HTTP is probably costing you a lot...what do you use it for?)

Also, one other tip: you might consider playing with the tmin parameter of BotConfig. I noticed once I added the include("precompile_includer.jl") that the time for plot dropped by half a second and the time for loading increased by half a second. Of course it's probably a net win because you've precompiled more than just plot, but do keep in mind that loading the cached inference results does, of course, take some time. You can use the tmin parameter to limit yourself just to things that take enough inference time that it's better to load them than it is to recompute them.

[daschw]

Thanks for the hints!

Also, seems unlikely to be the source of the crash reported in discourse, but do be careful about crashes in versions older than 1.4.2 (see the Julia PR linked from discourse)

We run our tests on 1.3.1 on all platforms.

Main stragglers are in dependent packages like PlotUtils and RecipesPipeline, and it's possible that you could add precompilation to those packages and get them covered, too.

I was planning on doing that. Thanks for the reminder!

[aminya]

Wait, this is strange. The bot should add include("precompile_includer.jl") automatically. I wonder it has failed to do so! 🤔

The log says it has done it! But it seems it is lost somewhere in the process. I need to test this offline and will get back to you.

I tested this offline, and I added more tests just in case. All pass. Even the artifact uploaded by the action has the "include("precompile_includer.jl")" in it. Maybe the Create_PR step has removed it for some reason!

https://github.com/JuliaPlots/Plots.jl/suites/862271274/artifacts/9944298

OK. This part of the script which tries to discard whitespace changes removes precompile_includer:

(git diff -w --no-color || git apply --cached --ignore-whitespace && git checkout -- . && git reset && git add -p) || echo done

Changing it to this solves the problem:

(git diff -w --no-color || (git diff -w --no-color | git apply --cached --ignore-whitespace && git checkout -- . && git reset && git add -p)) || echo done

[isentropic]

Http is used to fetch the latest plotly library, but yeah maybe there's a way to make it a system dependency or download it somehow faster

[BeastyBlacksmith]

Is this fixed?

[BeastyBlacksmith]

Doesn't seem so: #2881

[aminya]

I do not think SegFaults are related to this issue. The title is misleading, it was just a mistake for not including the precompilation files. I am waiting for @timholy to merge JuliaDebug/SnoopCompile.jl#122 that resolves that.

[aminya]

You can switch to the old precompilation backend (using snoopc) by changing the snoop_mode for julia <=1.3:

Plots.jl/deps/SnoopCompile/snoop_bot.jl

Line 3 in 5673ced

snoop_bot(

@static if VERSION <= v"1.3.9" 
	snoop_bot(
	    BotConfig(
	        "Plots",
	        yml_path= "SnoopCompile.yml",
	        else_os = "linux",
	        else_version = "1.4",
	    ),
	    joinpath(@__DIR__, "precompile_script.jl"),
		snoop_mode = :snoopc			# uses `snoopc` 
	)
else
	snoop_bot(
	    BotConfig(
	        "Plots",
	        yml_path= "SnoopCompile.yml",
	        else_os = "linux",
	        else_version = "1.4",
	    ),
	    joinpath(@__DIR__, "precompile_script.jl"),
	)
end