[isabelle-dev] Problem with jdk7 on big iron

[Makarius]

This is just a report on an incident reported by Cezary some days ago with 
Isabelle/c9d7ccd090e1 and components according to Admin/components/main 
(notably jdk-7u9 and scala-2.9.2).

The hardware: AMD Opteron(tm) with many cores and lots of GB RAM; running 
CentOS (Redhat Enterprice Linux clone).


The problem turned out to be most likely on the side of Oracle: running 
x86_64 jdk-7u9 here made the java process eat up a lot of resources, and 
poly doing very little.  It worked after switching java explicitly to x86 
mode, e.g. by editing the local copy of jdk-7u9/etc/settings and swapping 
the ${ISABELLE_PLATFORM64:-$ISABELLE_PLATFORM32} expression.

This incident is probably unrelated to the one on the thread 
https://mailmanbroy.informatik.tu-muenchen.de/pipermail/isabelle-dev/2012-December/003498.html 
where CPU time is approximately 0% not 100% and more.  So it gets its own 
mail thread here.

If anybody experiences similar problems with Java 7 on big iron, please 
say so.  (Oracle does have trackers for everything, but also very long 
turnaround times for anything happening there.)


 	Makarius