Why do we need a bunch of duplicate changes in jdk7u/hotspot ?

[Volker Simonis]

Hi,

could anybody please explain why it was necessary to reintegrate a
whole lot of changes into hs23 of jdk7u/hotspot which have been in the
hotspot repository since hs22 anyway?

This all happened with the following bulk integrations:

http://mail.openjdk.java.net/pipermail/jdk7u-dev/2012-April/002588.html
http://mail.openjdk.java.net/pipermail/jdk7u-dev/2012-April/002651.html

and it affects (among others):

7059019: G1: add G1 support to the SA
7092412: G1: Some roots not marked during an initial mark that gets an
evacuation failure
7045232: G1: pool names are inconsistent with other collectors (don't
have 'Space')
7068215: G1: Print reference processing time during remark
7091032: G1: assert failure when NewRatio is used
7092245: G1: Wrong format specifier in G1PrintRegionLivenessInfo header output
7092238: G1: Uninitialized field gc_efficiency in
G1PrintRegionLivenessInfo output
6484982: G1: process references during evacuation pauses
7075646: G1: fix inconsistencies in the monitoring data
7086533: G1: assert(!_g1->is_obj_dead(obj)): We should not be
preserving dead objs: g1CollectedHeap.cpp:3835
7097053: G1: assert(da ? referent->is_oop() :
referent->is_oop_or_null()) failed: referenceProcessor.cpp:1054
7097048: G1: extend the G1 SA changes to print per-heap space information
7092236: java/util/EnumSet/EnumSetBash.java fails
7092278: "jmap -finalizerinfo" throws
"sun.jvm.hotspot.utilities.AssertionFailure: invalid cp index 0 137"
7096366: PPC: corruption of floating-point values with DeoptimizeALot
7100165: JSR 292: leftover printing code in methodHandleWalk.cpp

Looking for each of this changes will show you that they are present
two times in the repository with exactly the same changesets. E.g.:
http://hg.openjdk.java.net/jdk7u/jdk7u4/hotspot/log?rev=7059019

Regards,
Volker