# Julia v1.9.0-beta2 is fast

**URL:** <https://discourse.julialang.org/t/julia-v1-9-0-beta2-is-fast/92290>\
**Category:** Performance\
**Created:** [December 29, 2022, 8:48pm UTC](https://discourse.julialang.org/t/julia-v1-9-0-beta2-is-fast/92290 "2022-12-29T20:48:32Z")\
**Posts on this page:** 1\
**Showing post:** 17

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**Author:** ![tim.holy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tim.holy/32/52_2.png) [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Post date:** [December 30, 2022, 12:42pm UTC](https://discourse.julialang.org/t/julia-v1-9-0-beta2-is-fast/92290/17 "2022-12-30T12:42:08Z")

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If you’re using [SnoopPrecompile](https://timholy.github.io/SnoopCompile.jl/stable/snoop_pc/) to compile a workload and you’re not seeing a big speedup on 1.9, your first stop should be to check for invalidations. _Checking_ for invalidations is easy, most Julia users should be able to do it. Fixing them is much harder than any of us would like, but if you open a new topic someone might be able to help you.

As a reminder, the recipe is to start a fresh session (even with `--startup=no` so it’s “clean”) and then:

```julia
using SnoopCompileCore
invs = @snoopr using ThePackageICareAbout;
tinf = @snoopi_deep some_workload_I_want_to_be_fast(args...);
using SnoopCompile
trees = invalidation_trees(invs);
staletrees = precompile_blockers(trees, tinf)

```

and see what is in `staletrees`. If it’s empty, you can rule out invalidation; if not, you have a problem _you_ need to fix. **Note that this is workload-dependent** : `some_workload_I_want_to_be_fast...` can be a `begin...end` block that exercises _all_ the functionality you want to be fast. If you later discover more stuff you want to be fast, you should repeat this analysis for that new workload. (If you just want to fix _all_ invalidations, look at `trees` instead, but often that’s a pretty large list…)

The “fault” is only rarely in the method listed as causing the invalidation, instead the usual fix is in the things that got invalidated by it. SnoopCompile’s documentation goes over strategies to analyze them more deeply and fix them, but again that treads into more difficult waters.

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_[View the full topic](https://discourse.julialang.org/t/julia-v1-9-0-beta2-is-fast/92290)._