HotSpot 16 and OpenJDK6

[Joseph D. Darcy]

Joe Darcy wrote:
> Andrew John Hughes wrote:
>> On 24 February 2010 00:28, Joe Darcy <Joe.Darcy at sun.com> wrote:
>>  
>>> Andrew John Hughes wrote:
>>>    
>>>> On 23 February 2010 20:10, Joseph D. Darcy <Joe.Darcy at sun.com> wrote:
>>>>
>>>>      
>>>>> Hello.
>>>>>
>>>>> Andrew John Hughes wrote:
>>>>>
>>>>>        
>>>>>> Here's the merge:
>>>>>>
>>>>>> http://cr.openjdk.java.net/~andrew/jdk6-hs16-merge/webrev.01/
>>>>>>
>>>>>> which now builds, thanks to this additional changeset from Daniel
>>>>>> Daugherty in baseline:
>>>>>> http://hg.openjdk.java.net/hsx/hsx16/baseline/rev/c9740f5ed5b4
>>>>>>
>>>>>>
>>>>>>           
>>>>> Good.
>>>>>
>>>>>
>>>>>        
>>>>>> It also includes an additional fix, also listed separately at:
>>>>>>
>>>>>> http://cr.openjdk.java.net/~andrew/jdk6-hs16-merge/webrev.02/
>>>>>>
>>>>>> which reverts an erroneous change from SIZE_FORMAT to %d in
>>>>>>
>>>>>> changeset:   734:dbbe28fc66b5
>>>>>> user:        twisti
>>>>>> date:        Fri Feb 27 03:35:40 2009 -0800
>>>>>> summary:     6778669: Patch from Red Hat -- fixes compilation errors
>>>>>>
>>>>>> fixing the build on x86_64.  We'll need a bug ID for this reversion.
>>>>>>
>>>>>>
>>>>>>           
>>>>> The webrev generally looks good, but I have a few questions and 
>>>>> comments
>>>>> before this goes back.
>>>>>
>>>>> Do you know why webrev shows so many files with zero changes?  I 
>>>>> assume
>>>>> this
>>>>> is an artifact of the merge.
>>>>>
>>>>>
>>>>>         
>>>> No, you're right that does seem strange.  All I did was a pull from
>>>> hs16 and then a merge.  Perhaps this is some webrev oddity?
>>>>
>>>> If you look at
>>>> http://mail.openjdk.java.net/pipermail/jdk6-dev/2010-February/001230.html 
>>>>
>>>> I included a diff of the merged OpenJDK6 against the hs16 master
>>>> (which includes Daniel's patch that is currently only in baseline).
>>>> It actually makes the other questions below a bit clearer.
>>>>
>>>>       
>>> Yes, that patch size is more manageable!
>>>
>>>    
>>>>> In hotspot_version, what are the semantics of JDK_PREVIOUS_VERSION?
>>>>>
>>>>>
>>>>>         
>>>> I'm not sure.  It doesn't seem to do much.  Its only use is to set a
>>>> default BOOTDIR AFAICS:
>>>>
>>>> # Find JDK used for javac compiles
>>>>
>>>> BOOTDIR=$(SLASH_JAVA)/re/j2se/$(PREVIOUS_JDK_VERSION)/latest/binaries/$(PLATFORM) 
>>>>
>>>>
>>>> (from hotspot/make/defs.make)
>>>>
>>>> We actually differ from hs16 by still using 1.5.0 rather than 1.6.0.
>>>> 1.5.0 implicitly seems to make more sense to me, because 1.6.0 is the
>>>> version being built.  But in practice, it doesn't seem to matter
>>>> unless you're relying on the contents of a /java tree.
>>>>
>>>>       
>>> I have a vague recollection of there being a particular reason why 
>>> this was
>>> upgraded to 1.6.0 so I'd prefer to see this kept as 1.6.0.
>>>
>>>    
>>>>> In terms of fixing the %d vs SIZE_FORMAT in vmError.cpp, I've filed
>>>>> 6929005
>>>>> "Fix format specifier in vmError.cpp."  However, I notice that the 
>>>>> JDK 7
>>>>> master still has %d in this location.  I'll approve going back 
>>>>> from %d ->
>>>>> SIZE_FORMAT in OpenJDK 6 conditional on the review and approval of a
>>>>> HotSpot
>>>>> engineer.
>>>>>
>>>>>
>>>>>         
>>>> Interesting; I didn't check OpenJDK7 and indeed you're right.  Looking
>>>> again at the diff, it seems that we don't apply part of the same
>>>> changeset:
>>>>
>>>> --- ../hs16/src/share/vm/utilities/vmError.hpp  2010-01-13
>>>> 14:35:26.651211783 +0000
>>>> +++ hotspot/src/share/vm/utilities/vmError.hpp  2010-02-17
>>>> 11:07:40.899854566 +0000
>>>> @@ -50,7 +50,7 @@
>>>>
>>>>   // additional info for VM internal errors
>>>>   const char * _filename;
>>>> -  int          _lineno;
>>>> +  size_t       _lineno;
>>>>
>>>>   // used by fatal error handler
>>>>   int          _current_step;
>>>>
>>>> keeping the size_t rather than using int.  So I'll change the fix to
>>>> be making vmError.hpp match hs16 and OpenJDK7, rather than changing
>>>> vmError.cpp.
>>>>
>>>> The remaining diffs are typos and license fixups from the previous
>>>> merge which need to go back to the main HotSpot tree.
>>>>
>>>>
>>>>       
>>> If vmError.hpp matches what is in JDK 7 and HS 16, I approve your 
>>> merge of
>>> HS 16 + Dan's fixes into OpenJDK 6.
>>>
>>>     
>>
>> Pushed.  I reused 6929005 as Fix HS16 merge issues in OpenJDK 6 to
>> make vmError.hpp and JDK_PREVIOUS_VERSION match hs16.  You should
>> probably update the bug itself to match :-)
>>
>>   
>
> A fine use for that bug id; content of the bug adjusted accordingly :-)
>
> -Joe

Hmm, after syncing my repos and doing a build, I see test 2 HotSpot 
regression test failures

    * compiler/6823453/Test.java : DeoptimizeALot causes fastdebug 
server jvm to fail with assert(false,"unscheduable graph")
    * compiler/6833129/Test.java : Object.clone() and Arrays.copyOf 
ignore coping with -XX:+DeoptimizeALot

both complaining of an unrecognized +DeoptimizeALot option.

-Joe