OpenJDK 6 b19 features?

[Joseph D. Darcy]

Andrew John Hughes wrote:
> On 19 February 2010 19:24, Joseph D. Darcy <Joe.Darcy at sun.com> wrote:
>   
>> Andrew John Hughes wrote:
>>     
>>> On 19 February 2010 18:36, Joseph D. Darcy <Joe.Darcy at sun.com> wrote:
>>>
>>>       
>>>> Andrew John Hughes wrote:
>>>>
>>>>         
>>>>> On 18 February 2010 08:27, Gary Benson <gbenson at redhat.com> wrote:
>>>>>
>>>>>
>>>>>           
>>>>>> Andrew John Hughes wrote:
>>>>>>
>>>>>>
>>>>>>             
>>>>>>> On 17 February 2010 17:55, Joseph D. Darcy <Joe.Darcy at sun.com> wrote:
>>>>>>>
>>>>>>>
>>>>>>>               
>>>>>>>> Andrew has already started work on updating HotSpot.
>>>>>>>>
>>>>>>>>
>>>>>>>>                 
>>>>>>> This will be ready to push as soon as the issue with Daniel's patch
>>>>>>> is resolved.
>>>>>>>
>>>>>>>
>>>>>>>               
>>>>>> Does this updated HotSpot have Zero in it?
>>>>>>
>>>>>>
>>>>>>
>>>>>>             
>>>>> No, the patches were applied to hs17.
>>>>>
>>>>> We could backport it though.  With hs16, we'll be using what is now
>>>>> the alternate HotSpot build for IcedTea6 that is closer to the version
>>>>> against which Zero was applied upstream.
>>>>>
>>>>> Joe, what do you think about making Zero available upstream in
>>>>> OpenJDK6?  It already ships with IcedTea6 and builds have passed the
>>>>> TCK.
>>>>>
>>>>>
>>>>>           
>>>> Hmm.  I'm not sure.  What would making Zero available upstream mean
>>>> exactly
>>>> for OpenJDK 6?  I'm inferring Zero in is sufficiently new versions of
>>>> HotSpot (hs17 vs hs16) given the presence of a src/cpu/zero directory in
>>>> the
>>>> JDK 7 HotSpot repo.  Would the rough proposal be to port the Zero fixes
>>>> applied to hs17 in JDK 7 to the hs16 in OpenJDK 6?
>>>>
>>>>
>>>>         
>>> It would.  In fact, there would be no work to speak of as IcedTea6
>>> already supports applying it to both hs14 and hs16 (the latter being
>>> much less work).  Having it upstream would simplify the IcedTea build
>>> a little and possibly make it available to more people.
>>>
>>> I'm sure Gary (Zero's main author) can also make some other good
>>> points for its inclusion... :-)
>>>
>>>       
>> What would be the impact of putting Zero in OpenJDK 6 b19 with any future
>> update of OpenJDK 6 to HotSpot 17, just doing work now versus later?
>>
>> -Joe
>>
>>     
>
> Past behaviour suggests that HotSpot 17 won't be stabilised; the
> HotSpot engineers seem to stabilise even numbered versions in a
> separate branch.  It's likely to be a while before hs18 appears as a
> stable branch and is ready for production use.
>
> The backported changesets would be the same as those applied to 17 so
> they should just merge cleanly when we do bump to hs18.  It works with
> the IcedTea forest, which often has changesets before they appear in
> JDK7 build drops, Zero being one of them.
>
> The vast majority of people using OpenJDK6 do so via IcedTea6 so I
> don't think it will make as big a difference as it may appear, but it
> will simplify the maintenance of Zero significantly.
>   

Okay; with the understanding that I won't be doing any Zero-specific QA 
procedures for OpenJDK 6, I approve Zero being backported to OpenJDK 6 
after HS 16 is backported there.

-Joe