8217827: [Graal] Some vmTestbase/nsk/jvmti/ResourceExhausted tests failing

[Daniil Titov]

Thank you, Chris!

Please review a new version of the change that makes the test ignored if Graal is enabled.

Webrev: http://cr.openjdk.java.net/~dtitov/8217827/webrev.02/
Bug: https://bugs.openjdk.java.net/browse/JDK-8217827 

Best regards,
Daniil



On 3/22/19, 7:59 PM, "Chris Plummer" <chris.plummer at oracle.com> wrote:

    Hi Daniil,
    
    So 8mb is enough to do at least 10,000 iterations and trigger JVMCI 
    initialization, but the amount of memory needed after the System.gc() is 
    more than the memory used by the loop (and then freed)? I wonder if more 
    compilation is being triggered after the System.gc() call, and that uses 
    a lot of memory.
    
    Also, I'm not comfortable with this concept of considering JVMCI to be 
    initialized. You're making assumptions on the internal state of JVMCI. 
    Other compilations could require other allocations that could end up 
    failing. You also don't know how JVMCI behavior might change in the 
    future, causing this test to fail again. Perhaps it is best not to run 
    these ResourceExhausted tests with JVMCI. Their reliability is dubious 
    enough already.
    
    thanks,
    
    Chris
    
    On 3/22/19 4:02 PM, Daniil Titov wrote:
    > Hi Chris,
    >
    > Addind -XX:+PrintCompilation flag shows that the first compiled method is java.lang.Object::<init>.
    >
    > Max heap size and parameter for the warmup stage (10K iterations) were found a posteriori, to ensure that JVMCI initialization is kicked but without throwing OutOfMemoryError.
    >
    > The heap increase is required otherwise a second OOME is thrown in the main thread after line 75 and in some cases even after line 86. It seems as JVMCI eats out all 8Mb of the heap.
    >
    >    75         System.gc();
    >    76         if ( ! Helper.checkResult("creating " + count + " objects") )
    >    77             return Consts.TEST_FAILED;
    >    78
    >    79         return Consts.TEST_PASSED;
    >    80     }
    >    81
    >    82     public static void main(String[] args) {
    >    83         args = nsk.share.jvmti.JVMTITest.commonInit(args);
    >    84
    >    85         int result = run(args, System.out);
    >    86         System.out.println(result == Consts.TEST_PASSED ? "TEST PASSED" : "TEST FAILED");
    >    87         System.exit(result + Consts.JCK_STATUS_BASE);
    >    88     }
    >
    > Best regards,
    > Daniil
    >
    > On 3/22/19, 2:09 PM, "Chris Plummer" <chris.plummer at oracle.com> wrote:
    >
    >      Hi Daniil,
    >      
    >      What triggers the JVMCI initialization, what (in general) is done during
    >      the initialization, and how did you come up with the 10k iterations and
    >      a 10s sleep to ensure that initialization is complete?
    >      
    >      What was the reason for the heap size increase? Does the OOME happen
    >      before 10k iterations if you don't increase the heap size?
    >      
    >      thanks,
    >      
    >      Chris
    >      
    >      On 3/22/19 1:53 PM, Daniil Titov wrote:
    >      > Please review the change that fixes the failure of the test when running with Graal.
    >      >
    >      > The problem here is that the test consumes all memory before JVMCI runtime is fully initialized. As a result the call to JVMCIRuntime::get_HotSpotJVMCIRuntime(CHECK_EXIT)
    >      > at src/hotspot/share/jvmci/jvmciCompiler.cpp:132 throws OutOfmemoryError that is caught by CHECK_EXIT macro that in turn calls JVMCICompiler::exit_on_pending_exception that performs vm_exit(-1).
    >      >
    >      > The fix increases the maximum heap size the test uses and adds a delay to ensure the JVMCI Runtime is fully initialized before proceeding with provoking OutOfMemoryError.
    >      >
    >      > Before the change  the test failure rate in Mach5 builds was about 25% . With this change after 900 rounds in Mach5 no failure was detected. The test execution time  with the change is 50 second.
    >      >
    >      > Webrev: http://cr.openjdk.java.net/~dtitov/8217827/webrev.01/
    >      > Bug: https://bugs.openjdk.java.net/browse/JDK-8217827
    >      >
    >      > Thanks!
    >      > --Daniil
    >      >
    >      >
    >      
    >      
    >
    >