# Is compile time significantly slower in 0.6?

**URL:** <https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764>\
**Category:** Internals & Design\
**Created:** [March 19, 2017, 10:59pm UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764 "2017-03-19T22:59:18Z")\
**Posts on this page:** 18\
**Page:** 1

<div class="post-metadata">

**Author:** ![dlfivefifty](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dlfivefifty/32/1959_2.png) [@dlfivefifty](https://discourse.julialang.org/u/dlfivefifty)\
**Post date:** [March 19, 2017, 10:59pm UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/1 "2017-03-19T22:59:18Z")

</div>

It seems to me that it takes much longer to call `using` on a package in 0.6 than in 0.5. Is this expected?

---

<div class="post-metadata">

**Author:** ![StefanKarpinski](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stefankarpinski/32/24_2.png) [@StefanKarpinski](https://discourse.julialang.org/u/StefanKarpinski)\
**Post date:** [March 19, 2017, 11:09pm UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/2 "2017-03-19T23:09:37Z")

</div>

There are still regressions being worked out. If you have a good example of a slow down, please report it as an issue.

---

<div class="post-metadata">

**Author:** ![dlfivefifty](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dlfivefifty/32/1959_2.png) [@dlfivefifty](https://discourse.julialang.org/u/dlfivefifty)\
**Post date:** [March 19, 2017, 11:14pm UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/3 "2017-03-19T23:14:18Z")

</div>

Here’s one example, note all required packages are precompiled.

0.5:

```julia
julia> @time using ApproxFun
INFO: Recompiling stale cache file /Users/solver/.julia/lib/v0.5/ApproxFun.ji for module ApproxFun.
  9.553372 seconds (2.80 M allocations: 120.003 MB, 1.23% gc time)

```

0.6:

```julia
julia> @time using ApproxFun
INFO: Recompiling stale cache file /Users/solver/.julia/lib/v0.6/ApproxFun.ji for module ApproxFun.
 37.945525 seconds (12.66 M allocations: 600.239 MiB, 1.03% gc time)

```

---

<div class="post-metadata">

**Author:** ![StefanKarpinski](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stefankarpinski/32/24_2.png) [@StefanKarpinski](https://discourse.julialang.org/u/StefanKarpinski)\
**Post date:** [March 20, 2017, 2:04pm UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/4 "2017-03-20T14:04:20Z")

</div>

That’s a bad regression and definitely worth reporting. To have it looked into, it needs to be reported as an issue, not just a message on discourse.

---

<div class="post-metadata">

**Author:** ![tknopp](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tknopp/32/3569_2.png) [@tknopp](https://discourse.julialang.org/u/tknopp)\
**Post date:** [March 20, 2017, 2:34pm UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/5 "2017-03-20T14:34:09Z")

</div>

Here is the link to create an issue on Github:

> **[Build software better, together](https://github.com/JuliaLang/julia/issues/new)**
>
> GitHub is where people build software. More than 100 million people use GitHub to discover, fork, and contribute to over 330 million projects.

---

<div class="post-metadata">

**Author:** ![StefanKarpinski](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stefankarpinski/32/24_2.png) [@StefanKarpinski](https://discourse.julialang.org/u/StefanKarpinski)\
**Post date:** [March 20, 2017, 3:21pm UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/6 "2017-03-20T15:21:11Z")

</div>

I think @dlfivefifty is familiar 😁

---

<div class="post-metadata">

**Author:** ![dlfivefifty](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dlfivefifty/32/1959_2.png) [@dlfivefifty](https://discourse.julialang.org/u/dlfivefifty)\
**Post date:** [March 20, 2017, 6:21pm UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/7 "2017-03-20T18:21:31Z")

</div>

A related issue: [https://github.com/JuliaLang/julia/issues/21113](https://github.com/JuliaLang/julia/issues/21113)

---

<div class="post-metadata">

**Author:** ![dlfivefifty](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dlfivefifty/32/1959_2.png) [@dlfivefifty](https://discourse.julialang.org/u/dlfivefifty)\
**Post date:** [March 24, 2017, 4:43am UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/8 "2017-03-24T04:43:03Z")

</div>

> [@StefanKarpinski](#):
>
> That’s a bad regression and definitely worth reporting

I still haven’t had time to put in a sensible GitHub issue. Interestingly, the total times in my Travis tests have gone _down_ by 30% in 0.6, from 45mins to 33mins:

> **[Travis CI - Test and Deploy with Confidence](https://app.travis-ci.com/JuliaApproximation/ApproxFun.jl/jobs/214491477)**
>
> Travis CI enables your team to test and ship your apps with confidence. Easily sync your projects with Travis CI and you'll be testing your code in minutes.

So not all bad news!

(Of course Travis isn’t an ideal performance testing environment, but it’s happened multiple times now.)

---

<div class="post-metadata">

**Author:** ![pkofod](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pkofod/32/2179_2.png) [@pkofod](https://discourse.julialang.org/u/pkofod)\
**Post date:** [March 24, 2017, 6:42am UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/9 "2017-03-24T06:42:05Z")

</div>

A bit hard for me to translate it to an MWE, but I have a `fit` function in a package I have yet to register, that used to compile very fast on v0.5, but now it can take up to 30 seconds to run it the first time (0.08 seconds after that).

---

<div class="post-metadata">

**Author:** ![dlfivefifty](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dlfivefifty/32/1959_2.png) [@dlfivefifty](https://discourse.julialang.org/u/dlfivefifty)\
**Post date:** [March 24, 2017, 7:01am UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/10 "2017-03-24T07:01:43Z")

</div>

@pkofod if you have a nice concise example, can you post an issue and link to this thread?

---

<div class="post-metadata">

**Author:** ![pkofod](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pkofod/32/2179_2.png) [@pkofod](https://discourse.julialang.org/u/pkofod)\
**Post date:** [March 24, 2017, 7:07am UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/11 "2017-03-24T07:07:43Z")

</div>

> [@dlfivefifty](#):
>
> @pkofod if you have a nice concise example, can you post an issue and link to this thread?

I will try to find an example. In the mean time, is there any way for me to see where it is spending time?

---

<div class="post-metadata">

**Author:** ![dlfivefifty](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dlfivefifty/32/1959_2.png) [@dlfivefifty](https://discourse.julialang.org/u/dlfivefifty)\
**Post date:** [March 24, 2017, 7:08am UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/12 "2017-03-24T07:08:46Z")

</div>

I only know of `@profile`

---

<div class="post-metadata">

**Author:** ![pkofod](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pkofod/32/2179_2.png) [@pkofod](https://discourse.julialang.org/u/pkofod)\
**Post date:** [March 24, 2017, 8:17am UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/13 "2017-03-24T08:17:43Z")

</div>

> [@StefanKarpinski](#):
>
> There are still regressions being worked out. If you have a good example of a slow down, please report it as an issue.

Does this mean that some of them _have_ been worked out? If so, I should probably build a version with these fixes before regression hunting all day. Would that just be `master` ?

edit: and by the way, the compiled code is faster, so that’s good, it’s just that compilation time that would be killing any demonstration of the software.

---

<div class="post-metadata">

**Author:** ![kristoffer.carlsson](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kristoffer.carlsson/32/22_2.png) [@kristoffer.carlsson](https://discourse.julialang.org/u/kristoffer.carlsson)\
**Post date:** [March 24, 2017, 8:46am UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/14 "2017-03-24T08:46:02Z")

</div>

It is tedious work but good MWE can get quick action: [https://github.com/JuliaLang/julia/issues/21081](https://github.com/JuliaLang/julia/issues/21081)

---

<div class="post-metadata">

**Author:** ![StefanKarpinski](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/stefankarpinski/32/24_2.png) [@StefanKarpinski](https://discourse.julialang.org/u/StefanKarpinski)\
**Post date:** [March 24, 2017, 1:26pm UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/15 "2017-03-24T13:26:07Z")

</div>

Yes, several have been addressed since 0.6-alpha, so try master if you can; we’re working on 0.6-beta soon as well, which will include those fixes.

---

<div class="post-metadata">

**Author:** ![pkofod](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pkofod/32/2179_2.png) [@pkofod](https://discourse.julialang.org/u/pkofod)\
**Post date:** [March 25, 2017, 6:44am UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/16 "2017-03-25T06:44:45Z")

</div>

Significantly improved on master compared to alpha! Great.

---

<div class="post-metadata">

**Author:** ![dlfivefifty](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/dlfivefifty/32/1959_2.png) [@dlfivefifty](https://discourse.julialang.org/u/dlfivefifty)\
**Post date:** [March 27, 2017, 10:44am UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/17 "2017-03-27T10:44:44Z")

</div>

I’ve tagged an issue:  
[https://github.com/JuliaLang/julia/issues/21173](https://github.com/JuliaLang/julia/issues/21173)

---

<div class="post-metadata">

**Author:** ![HarrisonGrodin](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/harrisongrodin/32/5214_2.png) [@HarrisonGrodin](https://discourse.julialang.org/u/HarrisonGrodin)\
**Post date:** [April 6, 2017, 11:30am UTC](https://discourse.julialang.org/t/is-compile-time-significantly-slower-in-0-6/2764/18 "2017-04-06T11:30:01Z")

</div>

I am experiencing a significant slowdown in REPL launch time - 0.6 takes about one second longer than 0.5. Not sure if it’s relevant to this specifically, but thought it might be worth noting.

 ![](https://global.discourse-cdn.com/julialang/original/3X/b/4/b4040430dd842531faedebc9901bdf5137740a92.png)