Add more precompile methods

[henry2004y]

Now we only have load in precompilation. We need more to take advantage of Julia 1.9.

• readvariable
• fillmesh
• getxxx

Maybe first take a look at how other packages handle this.

[henry2004y]

I still see the same issue as in #90: making readvariable into precompilation triggers extra 2 allocations. Why?

It is probably related to type instability! By adding readvariable(meta, "CellID") into precompilation I lost 8% of speed:

# Current no precompilation:
julia> @benchmark readvariable(meta, "CellID")
BenchmarkTools.Trial: 10000 samples with 9 evaluations.
 Range (min … max):  2.723 μs …   7.401 μs  ┊ GC (min … max): 0.00% … 0.00%
 Time  (median):     2.853 μs               ┊ GC (median):    0.00%
 Time  (mean ± σ):   2.938 μs ± 284.272 ns  ┊ GC (mean ± σ):  0.00% ± 0.00%

   ▃█▄                                                         
  ▂███▅▃▃▆▅▅▆▅▄▃▃▃▃▃▃▂▁▁▁▂▂▁▁▁▁▂▁▁▁▂▄▃▂▁▁▁▂▂▂▂▂▂▁▁▁▁▁▁▁▁▁▁▁▁▁ ▂
  2.72 μs         Histogram: frequency by time         3.6 μs <

 Memory estimate: 320 bytes, allocs estimate: 9.

# Precompile `readvariable`:
BenchmarkTools.Trial: 10000 samples with 8 evaluations.
 Range (min … max):  2.932 μs …   8.017 μs  ┊ GC (min … max): 0.00% … 0.00%
 Time  (median):     3.159 μs               ┊ GC (median):    0.00%
 Time  (mean ± σ):   3.254 μs ± 381.799 ns  ┊ GC (mean ± σ):  0.00% ± 0.00%

    █▃  ▃                                                      
  ▇███▇▆█▆▅▅▄▄▃▅▅▃▄▄▃▃▃▃▂▂▂▂▂▂▂▂▂▁▂▂▂▂▂▂▂▁▂▁▂▂▂▂▂▂▂▂▂▂▁▁▂▁▂▂▂ ▃
  2.93 μs         Histogram: frequency by time         5.3 μs <

 Memory estimate: 464 bytes, allocs estimate: 11.

file = "test/init.vlsv"
meta = load(file)
# no precompilation
julia> @time Vlasiator.fillmesh(meta, ["proton/vg_v", "CellID"], skipghosttype=true, maxamronly=true);
  0.328785 seconds (405.75 k allocations: 27.188 MiB)

julia> @time Vlasiator.fillmesh(meta, ["proton/vg_v", "CellID"], skipghosttype=true, maxamronly=true);
  0.000142 seconds (69 allocations: 2.859 KiB)
# with precompilation
julia> @time Vlasiator.fillmesh(meta, ["proton/vg_v", "CellID"], skipghosttype=true, maxamronly=true);
  0.000564 seconds (607 allocations: 35.359 KiB)

julia> @time Vlasiator.fillmesh(meta, ["proton/vg_v", "CellID"], skipghosttype=true, maxamronly=true);
  0.000104 seconds (73 allocations: 3.141 KiB)

Related to #127

[henry2004y]

Checking invalidations

using SnoopCompileCore
invalidations = @snoopr using Vlasiator;
tinf = @snoopi_deep begin
   file = "bulk.0000006.vlsv"
   meta = load(file)
   v = readvariable(meta, "proton/vg_rho")
end
using SnoopCompile

trees = invalidation_trees(invalidations)
staletrees = precompile_blockers(trees, tinf)

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

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

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

#=
# (optional) plot the number of children per method invalidations
import Plots
Plots.plot(
    1:length(trees),
    n_invalidations;
    markershape=:circle,
    xlabel="i-th method invalidation",
    label="Number of children per method invalidations"
)
=#
# (optional) report invalidations summary
using PrettyTables  # needed for `report_invalidations` to be defined
SnoopCompile.report_invalidations(;
     invalidations,
     process_filename = x -> last(split(x, ".julia/packages/")),
     n_rows = 0,  # no-limit (show all invalidations)
  )

[ Info: 160 methods invalidated for 18 functions

file name:line number	Function Name	Invalidations	Invalidations %
StaticArrays/QPt9n/src/SizedArray.jl:88	convert	36	23
StaticArrays/QPt9n/src/indexing.jl:370	unsafe_view	36	23
EzXML/ZNwhK/src/node.jl:40	convert	15	10
EzXML/ZNwhK/src/streamreader.jl:54	convert	10	6
FillArrays/xqile/src/FillArrays.jl:688	print_matrix_row	9	6
LaTeXStrings/pJ7vn/src/LaTeXStrings.jl:109	lastindex	8	5
LaTeXStrings/pJ7vn/src/LaTeXStrings.jl:112	nextind	7	5
FillArrays/xqile/src/trues.jl:26	to_indices	6	4
EzXML/ZNwhK/src/node.jl:32	convert	5	3
EzXML/ZNwhK/src/node.jl:1363	IteratorSize	5	3
StaticArrays/QPt9n/src/broadcast.jl:27	_axes	5	3
LaTeXStrings/pJ7vn/src/LaTeXStrings.jl:125	sizeof	4	3
LaTeXStrings/pJ7vn/src/LaTeXStrings.jl:117	getindex	3	2
StaticArrays/QPt9n/src/broadcast.jl:30	instantiate	2	1
LaTeXStrings/pJ7vn/src/LaTeXStrings.jl:108	firstindex	1	1
FillArrays/xqile/src/FillArrays.jl:555	unique	1	1
EzXML/ZNwhK/src/document.jl:200	write	1	1
StaticArrays/QPt9n/src/SOneTo.jl:57	getproperty	1	1

None of these comes within the package. What shall I do?

[henry2004y]

JuliaLang/julia#49567