C2 compiler bug closed as incomplete

Julien Nicoulaud julien.nicoulaud at gmail.com
Thu Jun 5 12:20:11 UTC 2014


Hi,

The bug is still present on 8u20 b17.

I managed to reproduce it on 8u20 b17 fastdebug with TracePartialPeeling
on, the logs are here:
https://dl.dropboxusercontent.com/u/62997/JDK-8038985/8u20-b17.zip

Regards,
Julien

2014-06-05 1:55 GMT+02:00 Vladimir Kozlov <vladimir.kozlov at oracle.com>:

> Hi Julien,
>
> Thank you for additional information. I added it to 8038985 bug report.
> So it look likes something went wrong in loop opts.
> I pointed in the bug report that it could be related to 8039050. It was
> fixed in jdk8u20 b12. I see that you tested 8u20 b05. Can you download and
> test latest 8u20 b17?
>
> Also, if you know how to build Hotspot JVM yourself, you can 'hg clone'
> latest sources from http://hg.openjdk.java.net/jdk8u/jdk8u/hotspot/ and
> build 'fastdebug' JVM. It has a lot of asserts which will help identify the
> problem. Just replace libjvm.so in jdk/jre/lib/amd64/server.
>
> Regards,
> Vladimir
>
>
> On 6/4/14 2:34 AM, Julien Nicoulaud wrote:
>
>> Hi,
>>
>> Here are some more tests as asked on the JIRA issue:
>>   -XX:-PartialPeelLoop : no crash
>>   -XX:-LoopUnswitching : still crashes
>>   -XX:-SplitIfBlocks : still crashes
>>   -XX:LoopUnrollLimit=0 : no crash
>>   -XX:-RangeCheckElimination : still crashes
>>
>> => so it looks like PartialPeelLoop is the cause of the crash.
>>
>> I also tried these tests:
>>   -XX:-PartialPeelAtUnsignedTests : no crash
>>   -XX:+TracePartialPeeling : no crash
>>   -XX:-BackgroundCompilation : no crash
>>   -XX:+TracePartialPeeling -XX:CICompilerCount=8 : no crash
>>
>> It looks like a concurrency issue in PartialPeelLoop, but I can't find a
>> way to reproduce it when logging is on.
>>
>> Regards,
>> Julien
>>
>>
>> 2014-04-11 11:39 GMT+02:00 Julien Nicoulaud <julien.nicoulaud at gmail.com
>> <mailto:julien.nicoulaud at gmail.com>>:
>>
>>
>>     Hi all, thanks for your answers.
>>
>>     I did some further testing and here is the results:
>>       - JDK 8u20-b05 : still crashes, but not always - logs at
>>     https://dl.dropboxusercontent.com/u/62997/JDK-8038985/8u20-b05.zip -
>>     core dump at
>>     https://dl.dropboxusercontent.com/u/62997/JDK-8038985/8u20-
>> b05/core.16369.tar.bz2
>>       - JDK 8u0 with -XX:-EliminateAutoBox : still crashes, but not
>>     always - logs at
>>     https://dl.dropboxusercontent.com/u/62997/JDK-8038985/8u0-
>> no-EliminateAutoBox.zip
>>
>>     Also, since the crash always seems to occur when inlining Trove's
>>     TCustomHashMap (http://trove.starlight-systems.com/) into my code, I
>>     tried to:
>>       - Upgrade Trove from 3.0.3 to 3.1a1 (from
>>     https://bitbucket.org/robeden/trove/downloads) => still crashes
>>       - Replace Trove by other hash map implementations => no crash
>>
>>     Regards,
>>     Julien
>>
>>
>>     2014-04-07 22:04 GMT+02:00 Christian Thalinger
>>     <christian.thalinger at oracle.com
>>     <mailto:christian.thalinger at oracle.com>>:
>>
>>
>>
>>         On Apr 7, 2014, at 2:39 AM, Volker Simonis
>>         <volker.simonis at gmail.com <mailto:volker.simonis at gmail.com>>
>> wrote:
>>
>>          > Really seems like a duplicate of
>>          > https://bugs.openjdk.java.net/browse/JDK-8032566 "8032566:
>>         Crash in
>>          > JIT when running Scala compiler (and compiling Scala std lib)"
>>          > although that one should have been fixed in jdk8 b127. On the
>>         other
>>          > hand it was not really fixed - just worked around by switched
>> off
>>          > autoboxing by default (you can double check with
>>          > -XX:-EliminateAutoBox).
>>          >
>>          > Maybe the problem also appears even with autoboxing switched
>> off?
>>          >
>>          > By the way, JIT replay data doesn't help without access to
>>         the involved classes.
>>
>>         Right.  We would need the classes extracted from the core file.
>>           Also I’ve moved the replay and hs_err data into files and
>>         attached them to the bug report because the bug was unreadable
>>         before.
>>
>>          >
>>          > Regards,
>>          > Volker
>>          >
>>          >
>>          >
>>          > On Sun, Apr 6, 2014 at 8:55 AM, Ivan Krylov
>>         <ivan at azulsystems.com <mailto:ivan at azulsystems.com>> wrote:
>>          >> bcc: discuss at openjdk.java.net <mailto:discuss at openjdk.java.
>> net>
>>          >> cc: hotspot-compiler-dev at openjdk.java.net
>>         <mailto:hotspot-compiler-dev at openjdk.java.net>
>>
>>          >>
>>          >>
>>          >> Hi Julien,
>>          >>
>>          >> Hotspot-compiler-dev is the right alias from discussing C2
>>         crashes. In the meantime may you can try the current the latest
>>         EA build like 8u20 b05 [1]?
>>          >>
>>          >> Thanks,
>>          >>
>>          >> Ivan
>>          >>
>>          >> [1] - https://jdk8.java.net/download.html
>>          >>
>>          >> On 05 Apr 2014, at 13:57 , Julien Nicoulaud
>>         <julien.nicoulaud at gmail.com <mailto:julien.nicoulaud at gmail.com>>
>>
>>         wrote:
>>          >>
>>          >>> Hi all,
>>          >>>
>>          >>> I don't know if it's the right place to discuss this, but
>>         here is my issue :
>>          >>>
>>          >>> I reported a VM crash in C2 compilation, but it was closed
>>         as incomplete
>>          >>> with the following comment "We need a clear instructions
>>         how to reproduce
>>          >>> the problem".
>>          >>>
>>          >>> I clearly explained in the report I could not provide a
>> simple,
>>          >>> self-contained test case to reproduce the bug, and I
>>         provided hs_err and
>>          >>> JIT replay log file instead.
>>          >>>
>>          >>> So what am I supposed to do in this case ? Debug it myself
>>         ? Or are there
>>          >>> another options so I can provide useful debug output ?
>>          >>>
>>          >>> Here is the bug report:
>>          >>> https://bugs.openjdk.java.net/browse/JDK-8038985
>>          >>> http://bugs.java.com/bugdatabase/view_bug.do?bug_id=8038985
>>          >>>
>>          >>> Regards,
>>          >>> Julien Nicoulaud
>>          >>>
>>          >>
>>
>>
>>
>>
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