HotSpot 17 merge

[Andrew Haley]

On 05/17/2010 12:44 PM, Erik Trimble wrote:
> 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?
>>
>> 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?
>>   
> http://hg.openjdk.java.net/hsx/hsx17/master/rev/357d4e2eb4dd
> 
> this changeset turns EA on.  It was putback at hs17-b01, so it's never
> been enabled in HS16 or before.
> 
> EA was on for all of HS17 testing, and we've been working on it, but
> it's /just/ not quite production-ready, and the decision was made to not
> spend the effort to try and fix it in HS17. We're hoping to get it fully
> fixed in the current HS.

One other thing: if I apply a patch to enable EA in an earlier
HotSpot, will it probably work well enough for me to do some
benchmarking?  I'm interested to know how much EA will help, even
though we can't ship it.

Andrew.