RFR (M): 6848902: [TESTBUG] The compiler/6589834/Test_ia32.java timed out

[Filipp Zhinkin]

Hi Vladimir,

thank you for watching at it.

On 07/11/2014 10:33 PM, Vladimir Kozlov wrote:
> 2 * availableProcessors() is still very big on Sparc machines (could 
> be > 100). Do we need more threads then available processors for bug 
> reproduction?
The more threads we have, the more our chances to reproduce issue.

Issue could be reproduced when method deoptimized at particular safepoint
and I don't see how to make this test more stable.

I executed this test w/ jdk6u17 on different platforms w/ different options
and here are results for three different approaches to choose threads count:

a) 2 * availableProcessors:
Test failed 111 times.
Test passed 57 times.

b) 1 * availableProcessors:
Test failed 58 times.
Test passed 100 times.

c) min(100, 2 * availableProcessors):
Test failed: 100 times.
Test passed:  68 times.

So I think we can cut off threads count by 100.
>
> Do not use one symbol f(), g() methods names. Use something like 
> foo(), bar() or test1(), test2().
Sure, I'll rename it.

Thanks,
Filipp.
>
> thanks,
> Vladimir
>
> On 7/11/14 8:24 AM, Filipp Zhinkin wrote:
>> Hi all,
>>
>> please review fix for 6848902.
>>
>> compiler/6589834/Test_ia32.java starts 100 threads with spin-loop inside
>> and on some hosts with small amount of CPU coresit takes too much time.
>>
>> Also there is another issue - test intended to catch interpreter's stack
>> corruption after deoptimization, but it can fail only on VM crash.
>> I've checked how it works w/ JDK 6u17 (where 6589834 was not fixed) and
>> found that issue may not cause VM crash. In suchsituation test just
>> prints message "Bug!", but do not actually fail.
>>
>> I reduced amount of used threads to 2 * availableProcessors()
>> and add more asserts on test results, so now it can catch original
>> issue even if VM doesn't crash.
>>
>> Also, VerifyStackwas added to test's options as it was suggested in
>> original test.
>>
>> After all, test still can reproduce original issue w/ 6u17.
>>
>> Testing: on local machine, automated on all platforms.
>> Bug: https://bugs.openjdk.java.net/browse/JDK-6848902
>> Webrev: http://cr.openjdk.java.net/~fzhinkin/6848902/webrev.00/
>>
>> Thanks,
>> Filipp.