Proposal for back-porting JFR to OpenJDK8u

[Hohensee, Paul]

Imo JFR is both a feature and a backport, so it was a bit hazy how to proceed. The Alibaba folks will know better than me, but I expect the work won't be a clean backport in the sense that "normal" backports are. It's really new feature development in an update release that's based on a feature in tip.

There are multiple patches involved, starting with the initial push https://bugs.openjdk.java.net/browse/JDK-8199712, followed up by various fixes, all of which should be backported too. So the backport will actually be a series of backports. Alternatively, the 8199712 backport could include all the followup patches, but then there would be no formal record of those patches being backported.

Alibaba presumably has a large initial patch that they'd like to publish as the basis for the backport. Do we manually create a backport issue for 8199712 and attach it to that and then work together by exchanging patches? Would a project repo be more efficient?

I believe a CSR will also be required, but there's no CSR to backport. Perhaps create a backport request for the JEP https://bugs.openjdk.java.net/browse/JDK-8193393 and get that approved first? Or, manually create an 8199712 backport issue, then an associated new CSR, and get the latter approved first?

Thanks,

Paul

On 12/7/18, 2:24 AM, "jdk8u-dev on behalf of guangyu.zhu" <jdk8u-dev-bounces at openjdk.java.net on behalf of guangyu.zhu at aliyun.com> wrote:

    thanks, it makes sense. 
    ------------------------------------------------------------------
    Sender:Andrew Haley <aph at redhat.com>
    Sent at:2018 Dec 7 (Fri) 17:57
    To:guangyu.zhu <guangyu.zhu at aliyun.com>; Mario Torre <neugens at redhat.com>
    Cc:jdk8u-dev <jdk8u-dev at openjdk.java.net>; kingsum.chow <kingsum.chow at gmail.com>
    Subject:Re: Proposal for back-porting JFR to OpenJDK8u
    
    On 07/12/2018 02:52, guangyu.zhu wrote:
    > I still don't understand why feature backport is the right approach. What's the difference between feature backport and JEP? Can you give more comments?
    
    JEPs are proposals for new Java features. This isn't one.
    This is an already-existing Java feature being backported.
    A JEP is a waste of time. Why do you want one?
    
    -- 
    Andrew Haley
    Java Platform Lead Engineer
    Red Hat UK Ltd. <https://www.redhat.com>
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