[11u] RFR: 8209061 & 8209062: G1MonitoringSupport changes

[Vladimir Kempik]

Hello
Any credible "gc experts" left on this mailing list ?
Or can we go forward with a single review from JohnC ?
Thanks in advance, Vladimir.
> 23 окт. 2020 г., в 21:12, Langer, Christoph <christoph.langer at sap.com> написал(а):
> 
> Hi Aleksey,
> 
> I'm wondering whether you could give an assessment about these changes, similar to what you've done regarding the proposed backport of JEP 346? I would hope this one would be less effort...
> 
> Thanks
> Christoph
> 
>> -----Original Message-----
>> From: Vladimir Kempik <vkempik at azul.com>
>> Sent: Dienstag, 13. Oktober 2020 22:01
>> To: Langer, Christoph <christoph.langer at sap.com>
>> Cc: John Cuthbertson <johnc at azul.com>; Andrew Haley
>> <aph at redhat.com>; Severin Gehwolf <sgehwolf at redhat.com>; Aleksey
>> Shipilev <shade at redhat.com>; jdk-updates-dev at openjdk.java.net
>> Subject: Re: [11u] RFR: 8209061 & 8209062: G1MonitoringSupport changes
>> 
>> Hello
>> 
>> Any objections about these patches ?
>> 
>> Regards, Vladimir.
>> 
>>> 17 сент. 2020 г., в 11:24, Vladimir Kempik <vkempik at azul.com>
>> написал(а):
>>> 
>>> Hello Langer
>>> 
>>>> Another thing: Looking at JBS I can see that JDK-8208498 was marked as a
>> blocker for JDK-8209061 and the former hasn't been backported to 11. Is that
>> an issue
>>>> Generally, would it be possible to fix the issue of JDK-8207200 in a way
>> that's less invasive?
>>> 
>>> well, I have tried to make 8207200 less invasive by not including 8208498.
>>> 
>>> There is a race condition in g1 monitoring which still can be see by some
>> openjdk11 users ( commited < used) and this is the attempt to fix it.
>>> I have verified it helps at least one user. Sadly I don’t have a reproducer.
>>> 
>>> Regards, Vladimir
>>> 
>>> 
>>>> 17 сент. 2020 г., в 10:43, Langer, Christoph <christoph.langer at sap.com>
>> написал(а):
>>>> 
>>>> Hi,
>>>> 
>>>> I've just looked at approving this series of backports (JDK-8209061, JDK-
>> 8209062 and JDK-8207200).
>>>> 
>>>> While I'm sure that JDK-8207200 fixes an important issue and I also trust
>> your reviews of the backports, I can see that these 3 patches together mean
>> some significant changes in the area of G1 GC. This makes me kind of
>> hesitant to approve the backports right away. I'd like to get some
>> assessment/reassurance of the other JDK11 maintainers (aph, sgehwolf) on
>> whether we should admit them or not?
>>>> 
>>>> Also, Aleksey, maybe you can give some technical advice as a gc expert if
>> you think these backports are feasible?
>>>> 
>>>> Another thing: Looking at JBS I can see that JDK-8208498 was marked as a
>> blocker for JDK-8209061 and the former hasn't been backported to 11. Is that
>> an issue?
>>>> 
>>>> Generally, would it be possible to fix the issue of JDK-8207200 in a way
>> that's less invasive?
>>>> 
>>>> Please understand that I'd like to err on the side of caution here...
>>>> 
>>>> Thanks & Best regards
>>>> Christoph
>>>> 
>>>>> -----Original Message-----
>>>>> From: jdk-updates-dev <jdk-updates-dev-retn at openjdk.java.net> On
>>>>> Behalf Of John Cuthbertson
>>>>> Sent: Dienstag, 15. September 2020 19:07
>>>>> To: Vladimir Kempik <vkempik at azul.com>
>>>>> Cc: jdk-updates-dev at openjdk.java.net
>>>>> Subject: Re: [11u] RFR: 8209061 & 8209062: G1MonitoringSupport
>> changes
>>>>> 
>>>>> Hi Vladimir,
>>>>> 
>>>>> On Sep 3, 2020, at 5:28 AM, Vladimir Kempik
>>>>> <vkempik at azul.com<mailto:vkempik at azul.com>> wrote:
>>>>> 
>>>>> Hello
>>>>> 
>>>>> Please review these backports of JDK-8209061:Move G1 serviceability
>>>>> functionality to G1MonitoringSupport  and JDK-8209062:Clean up
>>>>> G1MonitoringSupport to jdk11u
>>>>> 
>>>>> These backports are prerequestes for JDK-8207200 which we can see in
>> the
>>>>> wild with jdk8 and jdk11.
>>>>> 
>>>>> JDK-8209061 and JDK-8209062 applies mostly clean, very few places
>> where it
>>>>> wasn’t clean due to surrounding code or code layout.
>>>>> 
>>>>> after these two, JDK-8207200 applies cleanly.
>>>>> 
>>>>> Testing: tier1.
>>>>> 
>>>>> The webrevs:
>>>>> 
>>>>> http://cr.openjdk.java.net/~vkempik/8209061/webrev.00/
>>>>> 
>>>>> This looks good to me and matches
>>>>> http://hg.openjdk.java.net/jdk/jdk/rev/ec014e5694ec.
>>>>> 
>>>>> http://cr.openjdk.java.net/~vkempik/8209062/webrev.00/
>>>>> 
>>>>> This looks good to me also and matches
>>>>> http://hg.openjdk.java.net/jdk/jdk/rev/9a5200b84046.
>>>>> 
>>>>> 
>>>>> All mentioned bugs:
>>>>> https://bugs.openjdk.java.net/browse/JDK-8209062
>>>>> https://bugs.openjdk.java.net/browse/JDK-8209061
>>>>> https://bugs.openjdk.java.net/browse/JDK-8207200
>>>>> 
>>>>> Original changesets:
>>>>> 8209061: http://hg.openjdk.java.net/jdk/jdk/rev/ec014e5694ec
>>>>> 8209062: http://hg.openjdk.java.net/jdk/jdk/rev/9a5200b84046
>>>>> 
>>>>> Thanks, Vladimir
>>>>> 
>>>>> Regards,
>>>>> 
>>>>> JohnC
>>> 
>