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

[Vladimir Kozlov]

Nice!

Thank you,
Vladimir

On 9/1/16 11:03 AM, Dmitrij Pochepko wrote:
> 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
>>>>>>>>
>>>>>>
>>>>
>