JDK-6636598 : Regression in full gc times when heap is nearly full with -XX:+UseParallelOldGC
  • Type: Bug
  • Component: hotspot
  • Sub-Component: gc
  • Affected Version: 6u4p,7
  • Priority: P4
  • Status: Closed
  • Resolution: Duplicate
  • OS: generic
  • CPU: generic
  • Submitted: 2007-12-03
  • Updated: 2012-02-01
  • Resolved: 2008-01-15
Related Reports
Duplicate :  
JDK-6330863 - vm/gc/InfiniteList.java fails intermittently due to timeout problems
Relates :  
JDK-6392907 - Very slow FullGC with -XX:+UseParallelOldGC when running GC stress tests
Description
See comments.
Comments
WORK AROUND Use -Xmx1G on the command line to get the same default heap size as jdk7 b19 and earlier.
15-01-2008
EVALUATION The root cause is the same as 6630863: the parallel compacting collector cannot (yet) compact just part of eden into the old gen; either everything from eden must fit or nothing can be moved. This has been aggravated in jdk7 b20 by 6581118: For GC ergonomics on 64b server-class machines, remove the 1G maximum on default heap size. So the default heap size for 64-bit parallel gc on the indicated test machine has gone from 1G to 7.7G, with a corresponding increase in GC times.
15-01-2008