Differences between openjdk6 hotspot and hs14+

[Martin Buchholz]

Hi Andrew,

I'm checking the current state of hotspot 14 in openjdk6,
and noticed some discrepancies I can't explain.

This hunk:

--- /home/martinrb/ws/hsx14-master/src/share/vm/runtime/globals.hpp
2009-05-13 14:49:39.000000000 -0700
+++ /home/martinrb/ws/openjdk6/hotspot/src/share/vm/runtime/globals.hpp
2009-11-04 15:34:13.000000000 -0800
@@ -1494,7 +1497,7 @@
           "CMSPrecleanNumerator:CMSPrecleanDenominator yields convergence"
\
           " ratio")
\

\
-  product(bool, CMSPrecleanRefLists1, true,
\
+  product(bool, CMSPrecleanRefLists1, false,
\
           "Preclean ref lists during (initial) preclean phase")
\

\
   product(bool, CMSPrecleanRefLists2, false,
\


is from

# HG changeset patch
# User ysr
# Date 1227212861 28800
# Node ID 00b023ae2d78987955a9647b6d6d457bd39dec7e
# Parent  b5e603f2e02480180ace404141897cf8f6266e93
6722113: CMS: Incorrect overflow handling during precleaning of Reference
lists
Summary: When we encounter marking stack overflow during precleaning of
Reference lists, we were using the overflow list mechanism, which can cause
problems on account of mutating the mark word of the header because of
conflicts with mutator accesses and updates of that field. Instead we should
use the usual mechanism for overflow handling in concurrent phases, namely
dirtying of the card on which the overflowed object lies. Since precleaning
effectively does a form of discovered list processing, albeit with discovery
enabled, we needed to adjust some code to be correct in the face of
interleaved processing and discovery.
Reviewed-by: apetrusenko, jcoomes


Probably inadvertently reverted during a merge?


I found this by reviewing changes thusly

diff -Bw -x .hg -u -r  ~/ws/hsx14-master/ ~/ws/openjdk6/hotspot/

Martin
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