# Weird fluctuation in running time

**URL:** <https://discourse.julialang.org/t/weird-fluctuation-in-running-time/111818>\
**Category:** Performance\
**Created:** [March 19, 2024, 12:47pm UTC](https://discourse.julialang.org/t/weird-fluctuation-in-running-time/111818 "2024-03-19T12:47:06Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![abraemer](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/abraemer/32/51403_2.png) [@abraemer](https://discourse.julialang.org/u/abraemer)\
**Post date:** [March 19, 2024, 1:01pm UTC](https://discourse.julialang.org/t/weird-fluctuation-in-running-time/111818/2 "2024-03-19T13:01:08Z")

</div>

A couple of questions:

- What Julia version are you running?
- Just to confirm: If you keep on running `@benchmark StandardBasisVectors.standardize_basis($Q)` then at some point the code will slow down? You don’t do anything else?
- The link to your profile does not work for me.

While reading, my first suspicion was an interaction between GC, threading and calls to external libraries (like in this [recent thread](https://discourse.julialang.org/t/inconsistent-cpu-utilisation-in-threads-loops/110512/7)). But your code is just some normal Julia loops, no long BLAS operations and no multi-threading… So it indeed seems very odd that Task scheduling should be to blame for this slowdown. I am not even sure where Tasks come into the picture… Maybe the profile sheds some light on this.

---

_[View the full topic](https://discourse.julialang.org/t/weird-fluctuation-in-running-time/111818)._