HotSpot 17 merge

[Andrew John Hughes]

On 17 May 2010 20:54, Joe Darcy <joe.darcy at oracle.com> wrote:
> Andrew John Hughes wrote:
>>
>> On 17 May 2010 18:08, Vladimir Kozlov <vladimir.kozlov at oracle.com> wrote:
>>
>>>
>>> Andrew,
>>>
>>> yes, you should revert/remove the 6909480 changeset in OpenJDK6 after
>>> merge
>>> with hs17
>>>
>>> Vladimir
>>>
>>> Andrew John Hughes wrote:
>>>
>>>>
>>>> On 17 May 2010 17:29, Vladimir Kozlov <vladimir.kozlov at oracle.com>
>>>> wrote:
>>>>
>>>>>
>>>>> When we released jdk6u18 (hs16) there were 2 EA critical bugs
>>>>> for which we did not have time to fix in 6u18:
>>>>>
>>>>> http://hg.openjdk.java.net/jdk7/hotspot-comp/hotspot/rev/f96a1a986f7b
>>>>> http://hg.openjdk.java.net/jdk7/hotspot-comp/hotspot/rev/7fee0a6cc6d4
>>>>>
>>>>> In short, with escape analysis the generated code produces NULL(0)
>>>>> instead of expected (stored) values.
>>>>>
>>>>> There was no enough time for full testing in 6u18 and changes were too
>>>>> big.
>>>>> I would advice to not use EA with HS16.
>>>>>
>>>>> In hs17 we enabled EA again and tested it until 6u21 release in which
>>>>> the default flag's value is set to false but you can specify the flag
>>>>> on command line to enable EA. There are few problems which needs to be
>>>>> fixed before we enable EA by default.
>>>>>
>>>>> Andrew, you are right to not merge changes from hs16. And you can use
>>>>> the flag on command line for HS17 instead of patch to enable EA.
>>>>> It would be easier for benchmarking.
>>>>>
>>>>>
>>>>
>>>> Unfortunately it's not a matter of choosing not to merge the change,
>>>> but having to revert it as it's already part of OpenJDK6 from the
>>>> earlier hs16 merge (currently showing up as a difference between
>>>> OpenJDK6's HotSpot and the hs17 branch).  See the results and
>>>> discussion in the mail I just posted.
>>>>
>>>>
>>>>>
>>>>> Vladimir
>>>>>
>>>>> Andrew John Hughes wrote:
>>>>>
>>>>>>
>>>>>> On 16 May 2010 18:22, Andrew Haley <aph at redhat.com> wrote:
>>>>>>
>>>>>>>
>>>>>>> On 05/16/2010 05:14 PM, Andrew John Hughes wrote:
>>>>>>>
>>>>>>>>
>>>>>>>> The webrev is here:
>>>>>>>>
>>>>>>>> http://cr.openjdk.java.net/~andrew/jdk6-hs17-merge/
>>>>>>>>
>>>>>>>> I'd also like to revert:
>>>>>>>>
>>>>>>>> 6909480: Disable Escape Analysis in jdk 6u18
>>>>>>>> http://hg.openjdk.java.net/hsx/hsx16/master/rev/4ebd3f8407eb
>>>>>>>>
>>>>>>>> which isn't present in hs17 (and so remains a difference between
>>>>>>>> jdk6
>>>>>>>> and hs17) as, unlike jdk6's version, hs17 is based on the main
>>>>>>>> HotSpot
>>>>>>>> tree rather than the hs16 master.  I didn't include this in the
>>>>>>>> merge
>>>>>>>> because it's clearer what's going on if it appears as a separate
>>>>>>>> change.
>>>>>>>>
>>>>>>>
>>>>>>> Ahh, good catch.
>>>>>>>
>>>>>>> Do we have any idea why escape analysis is disabled?
>>>>>>>
>>>>>>> Andrew.
>>>>>>>
>>>>>>>
>>>>>>
>>>>>> I assume it wasn't stable enough in hs16, but the bug isn't visible.
>>>>>> Can someone from the HotSpot team shed more light on this?
>>>>>>
>>>>
>>>>
>>
>> Yeah :-)
>>
>> Just waiting for the go-ahead from Joe now...
>>
>
> Hello.
>
> I just finished looking over the lengthy patch.
>
> I approve the patch to update OpenJDK 6 to HS17 going back along with the
> subsequence reverting of 6909480.
>
> Thanks,
>
> -Joe
>

I've pushed the merge.  I guess I'll need a bug ID to push the
reversion.  Can you provide me with one?

Thanks,
-- 
Andrew :-)

Free Java Software Engineer
Red Hat, Inc. (http://www.redhat.com)

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