[regression] Julia 1.11 needs 60 % more compile time than Julia 1.10 with PackageCompiler 2.2

[donovaly]

As encouraged in Discourse I report a regression to Julia and purposely not to PackageCompiler because:

• run PackageCompiler 2.2 on Julia 1.10.9 on the same simple module and it is 60% faster than with Julia 1.11.5

Here is a MWE and what I encountered.

Since you can use the same PackageCompiler version and only change Julia, it must be a regression in Julia. 60% performance loss is so severe that this should be mentioned in the release notes of the next 1.11.x release that people are aware of.

[KSepetanc]

I would also like to point out to similarly higher RAM usage and resulting file sizes.

In my case v1.10 uses about 14GB RAM on Windows, ≈30GB on Linux, v1.11 increases that on Linux to ≈44GB, and got out of 64GB of RAM on v1.12 nightly (Linux). Numbers stated as remembered, but huge differences. Linux version uses much more RAM, but completes much faster (more than x2 speed for the last and longest timed step).

[ufechner7]

Linux uses multithreading for building the sysimage, Windows doesn't, that explains the difference in memory usage and performance. You can also limit the number of threads used on Linux to one by using export JULIA_IMAGE_THREADS=1 if you want to compare the single threaded performance with Windows, or if you are running out of RAM.