Closed
Description
Sorry if the title isn't too clear, I'm not exactly sure what is going on. I experienced a huge performance decrease in a project I'm working on after upgrading to julia 1.6. I posted about it here, and following @KristofferC's advice tried reverting fd8f97e, which solved the problem.
A MWE that shows the problem is
using BenchmarkTools
struct Model
ϕ # feature maps
end
y(ϕ) = x -> ϕ(x)
y(model::Model) = x -> model.ϕ(x)
y(model::Model, x) = model.ϕ(x)
ϕ = x -> x
M = Model(ϕ);
x = rand(100);
y(model::Model) = x -> model.ϕ(x)
@benchmark y($ϕ).($x) .* 1
@benchmark y($M).($x) .* 1 # <---- This takes much longer with fd8f97e than without
@benchmark y($M, $x) .* 1
This is an minimal as I could make it. The regression occurs when using the value of y($M).($x) (hence the .* 1). For julia installed from the Arch User Repository the results of the benchmark are:
julia> @benchmark y($M).($x) .* 1
BenchmarkTools.Trial:
memory estimate: 277.09 KiB
allocs estimate: 4286
--------------
minimum time: 3.082 ms (0.00% GC)
median time: 3.914 ms (0.00% GC)
mean time: 4.008 ms (0.42% GC)
maximum time: 7.155 ms (41.82% GC)
--------------
samples: 1245
evals/sample: 1
julia> versioninfo()
Julia Version 1.6.0
Commit f9720dc2eb* (2021-03-24 12:55 UTC)
Platform Info:
OS: Linux (x86_64-pc-linux-gnu)
CPU: Intel(R) Core(TM) i7-1065G7 CPU @ 1.30GHz
WORD_SIZE: 64
LIBM: libopenlibm
LLVM: libLLVM-11.1.0 (ORCJIT, icelake-client)
For julia master:
julia> @benchmark y($M).($x) .* 1
BenchmarkTools.Trial:
memory estimate: 285.91 KiB
allocs estimate: 4444
--------------
minimum time: 3.011 ms (0.00% GC)
median time: 3.393 ms (0.00% GC)
mean time: 3.549 ms (0.40% GC)
maximum time: 6.644 ms (38.91% GC)
--------------
samples: 1407
evals/sample: 1
julia> versioninfo()
Julia Version 1.7.0-DEV.1009
Commit 578d51857b* (2021-04-25 19:27 UTC)
Platform Info:
OS: Linux (x86_64-pc-linux-gnu)
CPU: Intel(R) Core(TM) i7-1065G7 CPU @ 1.30GHz
WORD_SIZE: 64
LIBM: libopenlibm
LLVM: libLLVM-11.0.1 (ORCJIT, icelake-client)
And finally for tag v1.6.0 with commit fd8f97e reverted:
julia> @benchmark y($M).($x) .* 1
BenchmarkTools.Trial:
memory estimate: 4.38 KiB
allocs estimate: 209
--------------
minimum time: 5.251 μs (0.00% GC)
median time: 6.084 μs (0.00% GC)
mean time: 6.344 μs (1.10% GC)
maximum time: 150.130 μs (94.01% GC)
--------------
samples: 10000
evals/sample: 6
julia> versioninfo()
Julia Version 1.6.1
Commit 3121d06bd6 (2021-04-25 18:53 UTC)
Platform Info:
OS: Linux (x86_64-pc-linux-gnu)
CPU: Intel(R) Core(TM) i7-1065G7 CPU @ 1.30GHz
WORD_SIZE: 64
LIBM: libopenlibm
LLVM: libLLVM-11.0.1 (ORCJIT, icelake-client)
I also tried reverting fd8f97e on master but there was a conflict in the affected code that I could not resolve.