Hello Alan, I found
http://mail.openjdk.java.net/pipermail/core-libs-dev/2015-March/032106.html and http://mail.openjdk.java.net/pipermail/build-dev/2016-February/thread.html#16602 but without much details on real or potential performance improvements . Both discussion threads are pretty old. I do not think they cover the changes done in the meantime in jdk9 and higher in the java.util.zip package . I think a lot of coding there moved from C to Java , so the libz is used in JDK less these days than in the "old times " . > > Sure but the opposite can arise too, say where someone is using a JDK > release that bundles an older version of zlib. > True , unfortunately the old JDK with bundled libz would not use the "great new current libz" from the distro (in case there is such a recent version available ), People would need to patch the JDK . At least we have the freedom to choose with the configure-flags . Best regards, Matthias > On 15/05/2019 09:16, Baesken, Matthias wrote: > > Hi Alan, thanks for pointing me at the old discussion . > > > > http://mail.openjdk.java.net/pipermail/build-dev/2016- > February/016602.html > > > > talks about performance benefits . Are you aware of some benchmarks > that showed the improvements ? > If you can find the mails that references the Intel IPP library then you > might have links to performance data comparing the different > implementations. There is also mails somewhere in the archive with a > proposal or patch to have the JDK select an alternative implementation > at run-time, equivalent to LD_PRELOAD. I think we ended up with the > right default. > > > > > In reality, if you have the latest distro versions you might be lucky and > > you > have a nice recent zlib 1.2.11 . > > However on older distros , you run in reality into older zlibs (often I > > see > 1.2.8). I don't think that this is a very good status . > Sure but the opposite can arise too, say where someone is using a JDK > release that bundles an older version of zlib. > > I agree with the comment that the building instructions need to be > sync'ed up. > > -Alan.
