Hi Geoff, We're neither using Less nor Java 8 anymore, but I tried to look into it.
The less4j library [0] Tapestry uses is a pure Java reimplementation of Less.js, so I don't think the performance issues come from there. Tapestry itself isn't dependent on the processor architecture, as it has no bundled executables, and the JDK/JRE interprets the generated Bytecode (also platform independent). That's why my guess is that the JDK/JRE 8 variant you're using is the possible culprit. According to JEP 391 [1], there wasn't full native macOS/AArch64 support until OpenJDK 17. As far as I understand it, there's no OpenJDK 8 arm64 build especially for Apple Silicon (I might be wrong on this one). However, Azul JDK seems to have backported Apple Silicon support to as low as 8 [2] Amazon Coretto also mentions dedicated support [3] My first try would be installing Azul or Coretto and testing it again for performance issues. With sdkman [4] or jabba [5], it's simple to install additional JDKs without polluting the default environment. But I haven't checked if they have the particular versions available om Mac. At least jabba is also available via homebrew [6]. Cheers Ben [0]: https://github.com/SomMeri/less4j [1]: https://openjdk.org/jeps/391 [2]: https://www.azul.com/newsroom/azul-announces-support-of-java-builds-of-openjdk-for-apple-silicon/ [3]: https://github.com/corretto/corretto-8/issues/297#issuecomment-1103974512 [4]: https://sdkman.io/ [5]: https://github.com/Jabba-Team/jabba [6]: https://formulae.brew.sh/formula/jabba On Sun, Jun 1, 2025 at 5:50 AM JumpStart < geoff.callender.jumpst...@gmail.com> wrote: > On Apple Silicon I’ve just switched from JDK 8 x86 version to JDK 8 arm64 > version, and I’m finding that while I’m running my Tapestry 5.4 app (in > Eclipse, debug, with the arm64 JRE selected), the compiling of Less files > (ResourceTransformerFactoryImpl) is at least 5 times slower. Our Less files > are big, so this is a major problem during development. > > Has anyone else had this problem? Is there a compiler involved that needs > to be upgraded too? Is there perhaps an arm64 version of Tapestry? > > Geoff
