RFR: 8293499: Provide jmod compression level option
Aleksey Shipilev
shade at openjdk.org
Mon Sep 12 10:42:45 UTC 2022
On Mon, 12 Sep 2022 10:15:26 GMT, Jaikiran Pai <jpai at openjdk.org> wrote:
>> I have been looking into `make clean-images images` performance, and realized jmod keeps compressing files with default compression level. Tuning that toward lighter compression levels improves build performance considerably, without a heavy loss in *.jmod sizes.
>>
>> This PR allows JMOD to select the compression level. Follow-ups would use this in the build system, see #10214.
>>
>> This change nominally requires CSR, but I would like to gauge the reaction to this patch first, before submitting a formal CSR. The interesting asymmetry against `jlink` is: `jlink` provides `--compress` option that only takes `2` for "ZIP compression". (Separately, we could argue if it would be beneficial to add `--compression-level` to `jlink` as well, so to select the compression level there too.)
>
> src/jdk.jlink/share/classes/jdk/tools/jmod/resources/jmod.properties line 85:
>
>> 83: main.opt.cmdfile=Read options from the specified file
>> 84:
>> 85: main.opt.compression-level=Compression level to use when compressing the JMOD archive.\
>
> Hello Aleksey, should this instead say "Compression level to use when creating the JMOD archive."?
Right. Done in new commit (to be published soon).
-------------
PR: https://git.openjdk.org/jdk/pull/10213
More information about the core-libs-dev
mailing list