Thanks, I'll try to use jstack with -F or -m! Uwe
----- Uwe Schindler uschind...@apache.org Apache Lucene PMC Member / Committer Bremen, Germany http://lucene.apache.org/ > -----Original Message----- > From: Krystal Mok [mailto:rednaxel...@gmail.com] > Sent: Wednesday, March 06, 2013 7:08 AM > To: Uwe Schindler > Cc: hotspot-gc-...@openjdk.java.net; hotspot-...@openjdk.java.net; > Dawid Weiss; dev@lucene.apache.org > Subject: Re: JVM hanging when using G1GC on JDK8 b78 or b79 (Linux 32 bit) > > Hi Uwe, > > If you can attach gdb onto it, and jstack -m and jstack -F should also work; > that'll get you the Java stack trace. > (But it probably doesn't matter in this case, because the hang is probably bug > in the VM). > > - Kris > > On Wed, Mar 6, 2013 at 5:48 AM, Uwe Schindler <uschind...@apache.org> > wrote: > > Hi, > > > > since a few month we are extensively testing various preview builds of JDK > 8 for compatibility with Apache Lucene and Solr, so we can find any bugs > early and prevent the problems we had with the release of Java 7 two years > ago. Currently we have a Linux (Ubuntu 64bit) Jenkins machine that has > various JDKs (JDK 6, JDK 7, JDK 8 snapshot, IBM J9, older JRockit) installed, > choosing a different one with different hotspot and garbage collector > settings on every run of the test suite (which takes approx. 30-45 minutes). > > > > JDK 8 b79 works so far very well on Linux, we found some strange behavior > in early versions (maybe compiler errors), but no longer at the moment. > There is one configuration that constantly and reproducibly hangs in one > module that is tested: The configuration uses JDK 8 b79 (same for b78), 32 > bit, and G1GC (server or client does not matter). The JVM running the tests > hangs irresponsible (jstack or kill -3 have no effect/cannot connect, standard > kill does not stop it, only kill -9 actually kills it). It can be reproduced > in this > Lucene module 100% (it hangs always). > > > > I was able to connect with GDB to the JVM and get a stack trace on all > threads (see attachment, dump.txt). As you see all threads of G1GC seem to > hang in a syscall (os:park(), a conditional wait in pthread library). > Unfortunately that’s all I can give you. A Java stacktrace is not possible > because the JVM reacts on neither kill -3 nor jstack. With all other garbage > collectors it passes the test without hangs in a few seconds, with 32 bit G1GC > it can stand still for hours. The 64 bit JVM passes with G1GC, so only the 32 > bit > variant is affected. Client or Server VM makes no difference. > > > > To reproduce: > > - Use a 32 bit JDK 8 b78 or b79 (tested on Linux 64 bit, but this > > should not matter) > > - Download Lucene Source code (e.g. the snapshot version we were > > testing with: > > https://builds.apache.org/job/Lucene-Artifacts-trunk/2212/artifact/luc > > ene/dist/) > > - change to directory lucene/analysis/uima and run: > > ant -Dargs="-server -XX:+UseG1GC" -Dtests.multiplier=3 > > -Dtests.jvms=1 test After a while the test framework prints "stalled" > messages (because the child VM actually running the test no longer > responds). The PID is also printed. Try to get a stack trace or kill it, no > response. Only kill -9 helps. Choosing another garbage collector in the above > command line makes the test finish after a few seconds, e.g. -Dargs="-server > -XX:+UseConcMarkSweepGC" > > > > I posted this bug report directly to the mailing list, because with earlier > > bug > reports, there seem to be a problem with bugs.sun.com - there is no > response from any reviewer after several weeks and we were able to help to > find and fix javadoc and javac-compiler bugs early. So I hope you can help for > this bug, too. > > > > Uwe > > > > ----- > > Uwe Schindler > > uschind...@apache.org > > Apache Lucene PMC Member / Committer > > Bremen, Germany > > http://lucene.apache.org/ > > > > > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional > commands, e-mail: dev-h...@lucene.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@lucene.apache.org For additional commands, e-mail: dev-h...@lucene.apache.org
