Hello, I’m new to Julia. I ran my code and timed it using @time . The results show that gc time is 67.2%. From what I’ve seen in other threads, this is a high figure and is a drag on performance. However, it is unclear to me (even after reading the documentation) what garbage collection is, what the…

Garbage collection is how memory is recovered from your program. It is a form of automatic memory management: languages like python, r and Java also have automatic memory management. Without it you need to make explicit calls in your code to tell the operating system you are done using memory. Lang…

It would be much easier to help if you provided an MWE. [image] Please read: make it easier to help you Meta Discussion Welcome to the Julia Discourse! We are enthusiastic about helping Julia programmers, both beginner and experienced. This public service announcement (PS…

How can I provide a MWE if I don’t know what garbage collection is and what in my code is generating it?

Not an actual expert on this, but garbage collection is basically freeing memory that you used in your calculation and is not required anymore. It can be a sign that you are overly reliant on creating lots of temporary arrays unnecessarily, which have to be allocated and freed, slowing down your cod…

Thanks for the explanation. So does that mean that 62.7% in gc time is that gc takes up 62.7% of the total time it takes to compute the code?

To be more specific 62% of the time the program was looking for blocks of memory that your program no longer needed and making them available for new data you were allocating. Garbage collection can take a long time if it has to rearrange blocks of memory or search through a lot of memory blocks, fo…

Maybe you can simplify the program to the point that it is small enough, yet it still displays a large amount of GC. This much garbage collection is somewhat unusual for idiomatic Julia code, but it is difficult to provide help without code to run. If you are looking for an explanation of what GC i…

[image] haberdashPI: Note that @time may not be accurate and you should probably use @btime from BenchmarkTools I would suggest @benchmark; @btime wontl be accurate for %gc time since it picks the minimum. Also, Julia’s GC is non-compacting, meaning it wont rearrange memory blocks. Lots of …

My experience follows: I had a method that when timed with TimeOutputs.jl gave a summed allocation of some GiB. This did not make sense to me as the method should deal with very small arrays that were just frequently rearranged. Then I discovered that permute! and sort! (using the keyword by) both …

Garbage collection

New to Julia

Tamas_Papp June 15, 2020, 10:41am 2

It would be much easier to help if you provided an MWE.

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Garbage collection

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