This is a really simple problem, and I’m not sure if I’m missing anything obvious here, but why is the following operation allocating memory? B = Matrix{Float64}(10,10^5); @time for j=1:10^5,i=1:10 B[i,j] = 1.0 end 0.023271 seconds (994.89 k allocations: 15.181 MB, 7.25% gc time)

Spurious allocation?

yuyichao May 16, 2017, 4:18pm 2

Don’t benchmark in global scope.

1 Like

CSV Reading (rewrite in C?)

Topic		Replies	Views
Allocations (again...) Performance question , allocations	15	656	November 25, 2022
@benchmark reporting (probably) wrong memory usage (BenchmarkTools.jl) Tooling	4	864	June 2, 2018
Why do `$`s in BenchmarkTools change allocations so dramatically? General Usage memory-allocation	14	1048	January 18, 2022
Understanding allocations in GeometryBasics.jl Performance	6	431	November 10, 2021
@benchmark resize! : no memory allocation? General Usage benchmarktools	5	516	March 14, 2021