RFR: 8349638: Build libjdwp with SIZE optimization

[Matthias Baesken]

On Tue, 11 Feb 2025 15:56:39 GMT, Matthias Baesken <mbaesken at openjdk.org> wrote:

> The libjdwp is currently built with LOW optimization level, it could be built with SIZE optimization to lower the lib size by ~ 10 % on UNIX.
> On Windows LOW and SIZE currently translate to the same O1 optimization flag so no difference there.
> 
> On Linux x86_64 for example the lib shrinks from
> 300K to 268K and the debuginfo file shrinks from 1.9M to 1.7M .
> 
> On Linux ppc64le for example the lib shrinks from
> 428K to 368K and the debuginfo file shrinks from 2.0M to 1.7M .

Hi Chris, thanks for the explanation and details of the minimal-vm .

> My point here is that if you want small footprint, you can choose that, and expect some performance hit as a result

Unfortunately , the JDK native libs are always compiled with the default settings (mostly LOW, for a few HIGH(EST))  so I cannot choose much. The minimal vm is interesting but as it is, it is not really a good choice.
Maybe we need better configure support to influence how the JDK libs are built.

On the other hand , most JDK libs have optimization LOW set, that does not look like they care too much about best performance.

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PR Comment: https://git.openjdk.org/jdk/pull/23563#issuecomment-2677689127