RFR (round 2), JEP-318: Epsilon GC

Aleksey Shipilev shade at redhat.com
Mon May 7 14:58:25 UTC 2018


This is round 2 code review for Epsilon GC changes.

JEP, targeted to 11:
  (you can find links to binary builds and sandbox locations there)



  *) See how the whole thing is almost completely isolated to hotspot/share/gc, without having
arch-specific mess -- thanks to GC interface work done over last years. The only leftover is the
change in graphKit.cpp that should go away after C2 barriers modularization [1] is complete;

  *) Recently added GC TLD facility and Elastic TLABs feature enables Epsilon to be more streamlined
in figuring out the TLAB sizes;

  *) Conditional GC compilation is supported. ISVs may choose not to build Epsilon, if they do not
want to extend whatever small notion of support that comes with experimental VM option [2].

  *) Half of the webrev are Epsilon-specific tests. They take ~30s in release and ~60s in fastdebug
on my desktop. They are not in tier1, so smoke testing time is not affected;

    server X {x86_64, x86_32, aarch64, arm32, ppc64le, s390x}
      zero X {x86_64}
   minimal X {x86}

Testing: gc/epsilon on x86_64


[1] https://bugs.openjdk.java.net/browse/JDK-8202377
[2] http://hg.openjdk.java.net/jdk/jdk/file/3661f31c6df4/src/hotspot/share/runtime/globals.hpp#l150

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 819 bytes
Desc: OpenPGP digital signature
URL: <https://mail.openjdk.java.net/pipermail/hotspot-gc-dev/attachments/20180507/8b1ffa42/signature.asc>

More information about the hotspot-gc-dev mailing list