On 2013-09-30 16:48, Coleen Phillimore wrote:
Hi, Stefan has found the cause of the problem you have described this
thread, but we're discussing internally how to fix it. I'll let him
explain.
First, my experiments were done without --indy so I might be seeing a
different issue than you are. On the other hand, the experiments shows a
real problem with our Metaspace and GC interaction, so I think that's
worth investigating.
The root cause of the problem I'm seeing is that SoftReferences are not
cleared when the GC is triggered because of high metaspace memory
pressure. I've created the bug:
https://bugs.openjdk.java.net/browse/JDK-8025635 - SoftReferences are
not cleared before metaspace OOME are thrown
StefanK
Thanks,
Coleen
On 09/26/2013 10:20 AM, Jochen Theodorou wrote:
Hi all,
probably not such a good time to ask, since many of those, that could
answer this might be on JavaOne... but still
On the user list we got an interesting program that makes quite some
problems to the jvm as it seems. The groovy program looks like this:
println "Started"
for(int i = 0; i < 100; i++) {
print "."
for (int j=0;j<100000;j++) {
Container c = new Container()
c.run()
}
}
println "\ndone"
public class Container implements Runnable {
public Container() {}
public void run() {
GroovyShell gs = new GroovyShell()
Script script = gs.parse("")
script.run()
}
}
What happens is that gs.parse will create a new script and a new class
every time. Now using our custom call site code this works fine. Using
the indy port, it fails with a permgen error on any jdk7 before u40. On
u40 this works fine again. In jdk8 this fails sometimes with a metaspace
error, while in u40 it seems to work quite reliable.
The problem must be more than just creating many classes, because our
custom callsite caching creates just as many classes for the scripts as
the indy version does. What does not happen so much there though is code
generated by reflection and of course non from indy. So I especially
suspect the code cache here to be responsible for the problem, but I
have no real basis for this. I lack the means to diagnose the problem
further
Is there a way to make this work on older jdk7 vms? And is there a way
for me to make this work on jdk8? Do others here have similar
experiences?
bye Jochen
_______________________________________________
mlvm-dev mailing list
mlvm-dev@openjdk.java.net
http://mail.openjdk.java.net/mailman/listinfo/mlvm-dev
