RFR(S): 8146096 - [TEST BUG] compiler/loopopts/UseCountedLoopSafepoints.java Timeouts

[Dmitrij Pochepko]

Hi,

I've added LoopUnrollLimit=0 to spawned vm options and tested on 
linux-amd64.

Please take a look at v04: 
http://cr.openjdk.java.net/~dpochepk/8146096/webrev.04/

Thanks,

Dmitrij

On 01.09.2016 20:47, Vladimir Kozlov wrote:
> I forgot an other useful C2 flag -XX:LoopUnrollLimit=0  to avoid loop 
> iteration splitting. Otherwise you will get several loops (pre-, main- 
> post-).
>
> Thanks,
> Vladimir
>
> On 9/1/16 10:40 AM, Vladimir Kozlov wrote:
>> Yes, this looks good.
>>
>> On 9/1/16 7:28 AM, Dmitrij Pochepko wrote:
>>> Thank you for attentive review.
>>>
>>>
>>>> Wow! You wrote "parser" to C2 Ideal graph.
>>>>
>>>> // now, find SafePoint->CountedLoopEnd edge
>>>>
>>>> Actually CountedLoopEnd  input edge should point to SafePoint. Not
>>>> reverse. You should search from LoopEnd up.
>>> fixed
>>>>
>>>>  115    SafePoint    ===  112  1  107  1  1  10  110  [[ 116 ]]
>>>> SafePoint !orig=76 !jvms: SimpleTest::testMethod @ bci:21
>>>>  116    CountedLoopEnd    ===  115  105  [[ 117  118 ]] [lt]
>>>> P=0.500000, C=6633.000000 !orig=97,[80] !jvms: SimpleTest::testMethod
>>>> @ bci:5
>>>>
>>>> The test is too simple. Without UseCountedLoopSafepoints the loop is
>>>> folded to accum += 100. You need a little more complex.
>>> I've changed increment to combination of different shifts
>>>>
>>>> Also test should be run only with C2 (Tiered should be off). I don't
>>>> think require vm.opt.TieredStopAtLevel is the same as
>>>> -XX:-TieredCompilation.
>>> Requires expression just help to ensure level 4 is available, because
>>> testMethod specifically compiled on level=4 using WhiteBox
>>> (CompilerWhiteBoxTest.COMP_LEVEL_FULL_OPTIMIZATION).
>>> This differs from original test idea to disable tiered compilation and
>>> trigger compilation by running cycle 2 billion times, which made it a
>>> long "stress" test. Now that method compiled via WhiteBox, this test
>>> became much more faster
>>
>> Got it.
>>
>> Thanks,
>> Vladimir
>>
>>>
>>> Please take a look at v03:
>>> http://cr.openjdk.java.net/~dpochepk/8146096/webrev.03/
>>>
>>> Thanks,
>>> Dmitrij
>>>>
>>>> Thanks,
>>>> Vladimir
>>>>
>>>> On 8/31/16 12:03 PM, Dmitrij Pochepko wrote:
>>>>> Hi,
>>>>>
>>>>> Please take a look at v02.
>>>>>
>>>>> I've rewritten this test. Now it launch vm with
>>>>> -XX:+UseCountedLoopSafepoints (restricting compilation to tested 
>>>>> method
>>>>> with single simple counted loop) and checks that output of
>>>>> -XX:+PrintIdeal have edge SafePoint -> CountedLoopEnd
>>>>>
>>>>> Then, launch the same with -XX:-UseCountedLoopSafepoints and checks
>>>>> that
>>>>> there is no such edge.
>>>>>
>>>>> I've tested fix via rbt on all platforms.
>>>>>
>>>>> webrev: http://cr.openjdk.java.net/~dpochepk/8146096/webrev.02/
>>>>>
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Dmitrij
>>>>>
>>>>> On 29.08.2016 19:28, Vladimir Kozlov wrote:
>>>>>> I am not against marking test as stress but I think the test 
>>>>>> itself is
>>>>>> not good. It should be rewrote. I added comment to the JBS with
>>>>>> discussion during original 8146096 RFR.
>>>>>>
>>>>>> Thanks,
>>>>>> Vladimir
>>>>>>
>>>>>> On 8/29/16 7:08 AM, Dmitrij Pochepko wrote:
>>>>>>> Hi,
>>>>>>>
>>>>>>> please review small fix for 8146096 - [TEST BUG]
>>>>>>> compiler/loopopts/UseCountedLoopSafepoints.java Timeouts
>>>>>>>
>>>>>>>
>>>>>>> Test timeouts on slow platforms, so, this fix adds execution 
>>>>>>> control
>>>>>>> with respect to elapsed time. Also, test marked as stress.
>>>>>>>
>>>>>>> webrev: http://cr.openjdk.java.net/~dpochepk/8146096/webrev.01/
>>>>>>>
>>>>>>> CR: https://bugs.openjdk.java.net/browse/JDK-8146096
>>>>>>>
>>>>>>>
>>>>>>> I've tested this fix on linux-amd64.
>>>>>>>
>>>>>>>
>>>>>>> Thanks,
>>>>>>>
>>>>>>> Dmitrij
>>>>>>>
>>>>>
>>>