RFR 8069291: [TESTBUG] Fibonacci test: OutOfMemoryError: unable to create native thread

[Dmitry Dmitriev]

Hello David,

Thank you for proposal. I was think about it, but finally decided to 
implement different fix. I leave the original thread creation logic, but 
exclude running this test on 32 bit JVM on Windows(via "@requires" jtreg 
tag).

New open webrev: 
http://cr.openjdk.java.net/~ctornqvi/webrev/8069291/webrev.01/ 
<http://cr.openjdk.java.net/%7Ectornqvi/webrev/8069291/webrev.01/>
JBS Bug: https://bugs.openjdk.java.net/browse/JDK-8069291

Regards,
Dmitry

On 17.02.2015 2:24, David Holmes wrote:
> On 17/02/2015 7:31 AM, Dmitry Dmitriev wrote:
>> Hi Christian,
>>
>> With this fix the N threads will be alive at the same time for N 
>> Fibonacci number. E.g. for 15th Fibonacci number at the same time 
>> will be 15 threads alive. Test takes small amount of time to run, 
>> less than a minute.
>>
>> But now I understand that for finding possible thread corruption it 
>> will be better to keep previous logic for creation threads. But in 
>> this case we need to limit maximum Fibonacci number for 32 bit 
>> systems to lower value, e.g. to 13. In this case only 751 threads 
>> will be created. For example 1973 threads are created for 15th 
>> Fibonacci number.
>
> So the usefulness of this seems to be as a stress test - in which case 
> scaling it back renders it less useful.
>
> I'm still inclined to treat the OOME as a transient error that may 
> affect some systems. Have the test not fail when that occurs if you 
> want to reduce testing noise.
>
> David
>
>> Thanks,
>> Dmitry
>>
>> ----- Original Message -----
>> From: christian.tornqvist at oracle.com
>> To: dmitry.dmitriev at oracle.com, hotspot-runtime-dev at openjdk.java.net
>> Sent: Tuesday, 17 February, 2015 12:02:44 AM GMT +03:00 Iraq
>> Subject: RE: RFR 8069291: [TESTBUG] Fibonacci test: OutOfMemoryError: 
>> unable to    create native thread
>>
>> Hi Dmitry,
>>
>> How many threads will usually be alive at the same time? How long 
>> does the test usually take to run?
>>
>> Thanks,
>> Christian
>>
>> -----Original Message-----
>> From: hotspot-runtime-dev 
>> [mailto:hotspot-runtime-dev-bounces at openjdk.java.net] On Behalf Of 
>> Dmitry Dmitriev
>> Sent: Friday, February 13, 2015 3:12 PM
>> To: hotspot-runtime-dev at openjdk.java.net
>> Subject: RFR 8069291: [TESTBUG] Fibonacci test: OutOfMemoryError: 
>> unable to create native thread
>>
>> Hello!
>>
>>
>>
>> Please review this fix for JDK-8069291. Unfortunately, the bug report 
>> isn't visible outside Oracle.
>>
>>
>> This test calculates Fibonacci numbers "recursively" via threads and 
>> compares the result with the classical calculation. I correct 
>> out-of-memory error which sometimes occurred on 32 bit systems. I 
>> changed how the recursive threads are created. Now left & right 
>> branches creates separately and thread wait one branch to finish 
>> before creating thread for another branch.
>>
>>
>> As part of the fixing the OOM issue I am moving the test to OpenJDK.
>>
>>
>> Open webrev: 
>> http://cr.openjdk.java.net/~ctornqvi/webrev/8069291/webrev.00/
>>
>>
>> JBS bug: https://bugs.openjdk.java.net/browse/JDK-8069291
>>
>>
>> I run this test on all main platforms; Linux x64, Linux x32, Win x32, 
>> Win x64, MacOS x64, Solaris x64, Solaris Sparc64
>>
>>
>> Thanks,
>> Dmitry
>>
>>