Modular LIBJVM.SO library for Docker

[Stefan Karlsson]

Hi Tibor,

On 2021-05-24 21:26, Tibor Digana wrote:
> Hi,
>
> The size of the library "libjvm.so"o is bigger than Java modules, and
> bigger or comparable with the size of the application in the Docker image.
>
> After processing the JDK by the JLINK and shrinking the native library "
> libjvm.so" my JRE is 35MB big in Docker image but the "libjvm.so" is too
> big, i.e. 18MB (from the original size 22MB) and the modules have only 12MB.
>
> We have many GC algorithms in the JVM and maybe this is the reason why the
> library is bigger than the Java modules and then JLINK does not become much
> effective.
>
> Can you please develop a modular JVM library so that I would be able to
> select only one algorithm of GC which means that the modules with other GC
> algorithms would not appear in my Docker image?

FWIW, we don't have a modular JVM, but we have support to remove GCs 
from the compilation of libjvm.so. All combinations are not always 
maintained, so you might have to propose patches to fix some of the 
issues you find.

If you run:
bash configure --help

you'll get a list of --enable-jvm-feature-X for the features you can 
compile into the JVM. Use corresponding --disable- flag to remove the 
feature. For example: --disable-jvm-feature-g1gc removes G1 from the 
libjvm.so.

HTH,
StefanK

>
> Thx
> Tibor