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

[Vladimir Kempik]

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
>