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

[Gil Tene]

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

-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: Message signed with OpenPGP
URL: <https://mail.openjdk.java.net/pipermail/hotspot-compiler-dev/attachments/20190410/439520c8/signature-0001.asc>