# Nested parallelization in Julia?
**URL:** https://discourse.julialang.org/t/nested-parallelization-in-julia/30568
**Category:** General Usage
**Created:** [November 1, 2019, 12:13am UTC](https://discourse.julialang.org/t/nested-parallelization-in-julia/30568 "2019-11-01T00:13:17Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@bashonubuntu](https://discourse.julialang.org/u/bashonubuntu)
#### Post date: [November 1, 2019, 12:13am UTC](https://discourse.julialang.org/t/nested-parallelization-in-julia/30568/1 "2019-11-01T00:13:17Z")
Hello,
I was curious to know if there has been some thought regarding nested parallelization in julia. For example, a typical parallelizable routine with a for loop inside may look like
```julia
function my_parallel_function()
@distributed () for i in 1:I
#do something
for j in 1:J
#do something else
end
end
end
```
In cases where both | I | and |J| are large it may be useful to parallelize the inner loop within the already parallelized outer-loop. I have written parallelized code over a collection of iterators but I am wondering if this was somewhere in the works too.
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### Author:  [@jling](https://discourse.julialang.org/u/jling)
#### Post date: [November 1, 2019, 6:22am UTC](https://discourse.julialang.org/t/nested-parallelization-in-julia/30568/2 "2019-11-01T06:22:52Z")
in `1.3`, you can nest `Threads.@threads` which can help here.
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### Author:  [@bashonubuntu](https://discourse.julialang.org/u/bashonubuntu)
#### Post date: [November 1, 2019, 6:25am UTC](https://discourse.julialang.org/t/nested-parallelization-in-julia/30568/3 "2019-11-01T06:25:21Z")
nice, that’s pretty cool. We only have 1.3.0-rc4 now though, but not the stable version yet – is that right?
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### Author:  [@jling](https://discourse.julialang.org/u/jling)
#### Post date: [November 1, 2019, 6:28am UTC](https://discourse.julialang.org/t/nested-parallelization-in-julia/30568/4 "2019-11-01T06:28:19Z")
that’s correct, you can try it now (I think rc4 is really close to release, which should happen within the year), if you don’t have mission-critical stability requirement.
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### Author:  [@bashonubuntu](https://discourse.julialang.org/u/bashonubuntu)
#### Post date: [November 1, 2019, 6:30am UTC](https://discourse.julialang.org/t/nested-parallelization-in-julia/30568/5 "2019-11-01T06:30:21Z")
Yes, will do and I also just dug up this link ([Announcing composable multi-threaded parallelism in Julia](https://julialang.org/blog/2019/07/multithreading)) which is useful and gives examples for what you mentioned in your first comment. Posting the link here in case some may have missed this blog post.