[aarch64-port-dev ] [RFC] ZGC proposal for aarch64 jdk11u

[Yangfei (Felix)]

Hi,

Currently, we only have zgc for the jdk11 x86 platform.  Zgc for aarch64 platform was later added in jdk13 by Stuart from Linaro.
So it’s an interesting question whether zgc for aarch64 platform should be backported to jdk11.

    Dozens of our arm-based cloud customers are switching to jdk11 and some of them have a strong demand for the zgc feature for their business.
To satisfy that requirement, we took the action to backport this feature in our jdk11 release.
But we think this work should not be kept private.  Other jdk11 vendors may come to the same problem.
It’s appreciated if this work could be incorporated in the upstream jdk11 repo and further improved.

    We have backported the following zgc related patches to jdk11u:
https://bugs.openjdk.java.net/browse/JDK-8217745
https://bugs.openjdk.java.net/browse/JDK-8224187
https://bugs.openjdk.java.net/browse/JDK-8214527
https://bugs.openjdk.java.net/browse/JDK-8224675<javascript:;>

   Basic test such as jtreg, jcstress looks good.  Specjbb2015 test with zgc gives us anticipated max & critical score.
    I can provide more details and propose a webrev for the backport.  But before that I would like to hear your comments & suggestions.

Thanks,
Felix