RFR (XS) JDK-8015272: Make @Contended within the same group to use the same oop map

[Aleksey Shipilev]

Hi Karen,

Thanks for looking into this.

On 11/06/2014 06:01 PM, Karen Kinnear wrote:
> I agree with Christian that it is too late for jdk8u.

...and I am not advocating for the inclusion to jdk8u, as you can see in
my today's message. This minor cleanup may be done in jdk9 only,
therefore jdk8u schedule does not apply.

> Could you please do additional testing  

Sure, that would take a while. I'm not sure why we need to burn time on
this trivial change, since the the code is copied 1:1 from the same
well-exercised codepath for non- at Contended oops, and additionally
exercised by runtime jtreg tests.

Anyhow:

> - e.g. what about the vmtestbase vm/runtime/contended tests (and yes, some tests should be removed from that testlist)

Submitted the test job, no progress yet.

> - vmtestbase: vm.quick.testlist (required for runtime changes)

Submitted the test job, no progress yet.

> - and since @Contended annotation is used in the JDK core libraries - the jtreg jdk tests?

There are two group of @Contended users: java/lang/Thread and
java/util/concurrent/*. jdk/test/java/lang and
jdk/test/java/util/concurrent jtreg tests yield no new failures on my
Linux x86_64/fastdebug. The testing jobs submitted above should run them
on all platforms.


> Does @Contended sometimes run into platform-specific bugs? Looking through earlier bugtails
> I see bugs only filed against specific platforms, but it is not clear to me if the bugs also were seen
> on other platforms and not recorded.

@Contended handling code is platform-agnostic, we haven't seen the
platform-specific bugs there.

> So the question is - is this a feature that needs testing on multiple platforms?

No, I don't think so.

Thanks,
-Aleksey.

> thanks,
> Karen
> 
> On Nov 6, 2014, at 8:00 AM, Aleksey Shipilev wrote:
> 
>> Hi,
>>
>> The Halloween is over, but here is a creepy undead patch from the past.
>>  http://cr.openjdk.java.net/~shade/8015272/webrev.01/
>>  https://bugs.openjdk.java.net/browse/JDK-8015272
>>
>> 8u does not need the patch, but it would be nice to have it in 9.
>>
>> I have checked:
>>  * Still the same chunk of code as for non- at Contended cases
>>  * Still builds fine on Linux x86_64 fastdebug/release
>>  * Still passes all hotspot/test/runtime jtreg tests
>>  * Still passes the JPRT
>>
>> Thanks,
>> -Aleksey.
>>
>> On 10/14/2013 01:01 AM, Aleksey Shipilev wrote:
>>> Hi Christian,
>>>
>>> Your call. I'm merely announcing the patch is ready. :)
>>>
>>> -Aleksey.
>>>
>>> On 10/13/2013 10:02 PM, Christian Tornqvist wrote:
>>>> Hi Aleksey
>>>>
>>>> We're well past Feature Complete (May 23) and Zero Bug Bounce is around the
>>>> corner, this is not the time to push enhancements. In my opinion this should
>>>> be done in the next 8u or in jdk9.
>>>>
>>>> Thanks,
>>>> Christian
>>>>
>>>> -----Original Message-----
>>>> From: hotspot-runtime-dev-bounces at openjdk.java.net
>>>> [mailto:hotspot-runtime-dev-bounces at openjdk.java.net] On Behalf Of Aleksey
>>>> Shipilev
>>>> Sent: Sunday, October 13, 2013 12:11 PM
>>>> To: hotspot-runtime-dev at openjdk.java.net
>>>> Subject: RFR (XS) JDK-8015272: Make @Contended within the same group to use
>>>> the same oop map
>>>>
>>>> Hi,
>>>>
>>>> Please review the simple improvement:
>>>>  http://cr.openjdk.java.net/~shade/8015272/webrev.00/
>>>>
>>>> I have copy-pasted the same block from the non- at Contended handling, because
>>>> it is generic for both cases. The change is also on the path which is
>>>> excercized only with @Contended with the same tag. Both @Contended
>>>> regression tests cover this case, as well as j.l.Thread containing
>>>> @Contended over the TLR state implicitly tests it in every VM run.
>>>>
>>>> Testing:
>>>> - Linux x86_64 fastdebug/release: all hotspot/test/runtime jtreg
>>>> - JPRT full cycle against hotspot-rt
>>>> - vm.quick (running)
>>>>
>>>> -Aleksey.
>>>>
>>>
>>
>>
>