[8u] RFR: 8221355: Performance regression after JDK-8155635 backport into 8u

[Gil Tene]

Since there is a time crunch on this, and no new update has been posted in the
thread in the past ~35 hours in response to the below, we will proceed with the
assumption that the plan in the e-mail from Andrew Hughes below (to include
the pushed patch in an expected final 8u212-b04) is going forward. Lets not
change from that at this late point.

In future cycles, I think that we probably need a bit more time for review and
input before making such a call so close to the final release. We went from
first identification (https://mail.openjdk.java.net/pipermail/jdk8u-dev/2019-April/009074.html )
to decision (https://mail.openjdk.java.net/pipermail/jdk8u-dev/2019-April/009086.html)
in under 7 hours, which occurred between 1:39AM and 8:26AM Pacific time.

— Gil.

> On Apr 10, 2019, at 12:29 PM, Gil Tene <gil at azul.com> wrote:
> 
> Before we jump ahead and integrate this into the upcoming April 8u212, and bump the
> build number from b03 to b04, I'd like to point out that the Oracle backport
> (https://bugs.openjdk.java.net/browse/JDK-8221954) appears to be to their 8u212 b31,
> which is likely a BPR, and not the initial version of 8u212 that will be out in a week.
> 
> So the premise that not including this in the initial version of OpenJDK 8u212 will lead to a
> performance regression compared Oracle's 8u212 is not quite right. The difference will
> happen when oracle publishes their 8u212-b31.
> 
> Given the time crunch, the risk, and the fact that Oracle's April 16 update will likely NOT
> include this fix to the regression initially introduced in 8u202, I would advocate to still build
> a 8u212-b03, which would not include this back-port, and to either do a b04 later, or push
> this to July.
> 
> — Gil.
> 
>> On Apr 10, 2019, at 8:26 AM, Andrew John Hughes <gnu.andrew at redhat.com> wrote:
>> 
>> 
>> 
>> On 10/04/2019 12:25, Aleksey Shipilev wrote:
>>> On 4/10/19 1:18 PM, Severin Gehwolf wrote:
>>>> Could I please get a review of this 8u212 performance regression fix?
>>>> webrev: http://cr.openjdk.java.net/~sgehwolf/webrevs/JDK-8221355/01/webrev/
>>> 
>>> This is not the same patch that Oracle apparently pushed, or that I tested myself. Compare with:
>>> http://cr.openjdk.java.net/~shade/8221355/8221355-01.patch
>>> 
>>> The difference is not critical, but better match?
>>> 
>>> It should definitely be in 8u-dev (next CPU). I'll leave the decision for 8u (current CPU) to 8u
>>> maintainers.
>>> 
>>> -Aleksey
>>> 
>> 
>> 
>> I think it should be 8u212 to avoid a performance regression between
>> OpenJDK 8u212 and Oracle's 8u212.
>> 
>> Once Severin has pushed his patch, I'll pull that into my local version
>> of jdk8u and the result will be tagged jdk8u212-b04.
>> --
>> Andrew :)
>> 
>> Senior Free Java Software Engineer
>> Red Hat, Inc. (http://www.redhat.com)
>> 
>> PGP Key: ed25519/0xCFDA0F9B35964222 (hkp://keys.gnupg.net)
>> Fingerprint = 5132 579D D154 0ED2 3E04  C5A0 CFDA 0F9B 3596 4222
>> https://keybase.io/gnu_andrew
>