WSL building performance and questions

[erik.joelsson at oracle.com]

Hello Chen,

On 5/5/23 22:42, - wrote:
> Hello,
> While I was trying to diagnose the problem that JMH benchmarks can't 
> be run on a fresh cygwin or WSL environment, 
> https://bugs.openjdk.org/browse/JDK-8305669 I found myself troubled 
> with path issues and slow building speed with a Windows target. 
> Meanwhile the linux target is totally fine.
>
> 1. When I pass --with-jmh=build/jmh/jars in WSL configuration, it 
> always fails to find the relative directories (not present on linux 
> configuration). C:\\...\\jdk\\build\\jmh\\jars doesn't work. Only 
> /mnt/c/.../jdk/build/jmh/jars work. Is this a bug?
I would say it's a bug.
>
> 2. My Windows WSL build is extremely slow. My windows target has 
> almost stalled that it stuck on creating benchmark jar without even 
> progressing to indify. And it seems WSL (Ubuntu) itself is only using 
> 400MB of RAM with almost no CPU usage. However, these problems don't 
> happen for my Linux target builds; meanwhile my cygwin builds are 
> blazingly fast. What could be the cause of this slowness?
>
Are you running WSL 1 or 2? From what I've heard, WSL 2 doesn't work 
well when having to interact with native Windows tools (which the 
windows build has to do). Most reports I've heard about WSL 1 say it's 
slightly faster than Cygwin, but different people and different 
environments have different results.

/Erik