RFR: 8290981: Enable CDS for zero builds [v2]

[Erik Joelsson]

On Sun, 14 Aug 2022 05:52:01 GMT, Ioi Lam <iklam at openjdk.org> wrote:

>> Enable CDS for zero builds. `java --version` is about 2x faster now.
>> 
>> 
>> $ perf stat -r 40 ./images/jdk/bin/java -Xshare:off -version
>> 0.034645 +- 0.000044 seconds time elapsed  ( +-  0.13% )
>> $ perf stat -r 40 ./images/jdk/bin/java -version
>> 0.018080 +- 0.000388 seconds time elapsed  ( +-  2.15% )
>> 
>> I also fixed a bug in Images.gmk that always wrote the default archive to $JAVA_HOME/lib/server. This fix also makes it possible for a client libjvm to have a default CDS archive.
>
> Ioi Lam has updated the pull request incrementally with two additional commits since the last revision:
> 
>  - create_cds_archive -> CreateCDSArchive
>  - explicitly choose VM variant in create_cds_archive

Build changes look good.

make/Images.gmk line 144:

> 142: 
> 143:   $$(eval $$(call SetupExecute, $1_$2_gen_cds_archive_jre, \
> 144:       WARN := Creating CDS$$($1_$2_DUMP_TYPE) archive for jre image, \

Perhaps include the variant name in the log message here, as is done above for the jdk image?

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Marked as reviewed by erikj (Reviewer).

PR: https://git.openjdk.org/jdk/pull/9869