RFR (smallish?) 8061611: Remove deprecated command line flags

Jon Masamitsu jon.masamitsu at oracle.com
Mon Nov 24 18:21:18 UTC 2014


On 11/24/2014 03:55 AM, Bengt Rutisson wrote:
>
> Hi Derek,
>
> Sorry for taking so long to review this.
>
> On 2014-11-18 17:40, Derek White wrote:
>> Hi Team,
>>
>> First review request. Please let me know if I've forgotten something 
>> or have gone completely off the rails.
>>
>> The main point of this bug is to remove deprecated -XX options which 
>> are alias for other options.
>>
>> The only complicated part is that one case, 
>> /CMSParPromoteBlocksToClaim/ was not a true alias for /OldPLABSize/ 
>> but a parallel option with different defaults that were synchronized 
>> in ergo processing. This fix removes the /CMSParPromoteBlocksToClaim 
>> /variable but preserves using different defaults in the CMS case.
>>
>> Also in this fix I added warning messages to several remaining 
>> undocumented command line options aliases. This should ease removal 
>> of these options in the future
>> CMSMarkStackSize ==> MarkStackSize        (MarkStackSize not documented either, but came in jdk6)
>> G1MarkStackSize  ==> MarkStackSize
>> CMSMarkStackSizeMax ==> MarkStackSizeMax  (MarkStackSizeMax not documented either)
>> ParallelMarkingThreads =>  ConcGCThreads  (ConcGCThreads came in jdk6)
>> ParallelCMSThreads     ==> ConcGCThread
>>
>> Thanks,
>>  - Derek
>>
>> *Webrev*: http://cr.openjdk.java.net/~drwhite/8061611/webrev.00/
>>
>> *Bug*: https://bugs.openjdk.java.net/browse/JDK-8061611
>
> Looks good to me. One minor nit regarding the naming of the new 
> constants that you introduce:
>
>  682   static const int defaultDynamicOldPLABSize = 16;
>  683   static const int defaultStaticOldPLABSize  = 50;
>
> HotSpot does not have a common guideline for how to name constants. 
> There are at least three widely used naming standards:
>
> - All caps: DEFAULT_DYNAMIC_OLD_PLAB_SIZE
> - Like an instance variable: _default_dynamic_old_plab_size
> - Like a flag: DefaultDynamicOldPLABSize
>
> I think it is hard to say which one is "standard" but I would prefer 
> if we don't introduce yet another naming standard for constants. Do 
> you mind changing to one of these? Personally I prefer the last one 
> (the "Like a flag" version).

Sorry for this Derek, but I prefer the "_default_dynamic_old_plab_size"
because of the leading "_".  It is least likely to  confuse me (as does
like a flag or like an All caps macro).

But as Bengt says, there is no standard.

Jon

>
> Bengt
>
>>
>> *Testing*:
>> jprt:
>>     Saw 1-2 intermittent failures that went away on retesting - hangs 
>> and timeouts.
>>
>> refworkload:
>>     no differences
>>
>> jtreg: Saw a few unexplained results. Not sure if typical or not:
>>
>>
>>             Execution failed: `main' threw exception:
>>             java.lang.Exception: jmap -heap exited with error code: 1
>>
>>       * gc/metaspace/CompressedClassSpaceSizeInJmapHeap.java
>>         <http://oklahoma.us.oracle.com/net/bussund0416//export/users/drwhite/hs-gc-mine/hotspot/test/JTwork/gc/metaspace/CompressedClassSpaceSizeInJmapHeap.jtr>:
>>         Checks that jmap -heap contains the flag
>>         CompressedClassSpaceSize
>>
>>
>>             Program
>>             `/export/users/drwhite/test-builds/j2sdk-image.11.17.2014/bin/java'
>>             interrupted! (timed out?)
>>
>>       * closed/runtime/AppCDS/SharedArchiveConsistency.java
>>         <http://oklahoma.us.oracle.com/net/bussund0416//export/users/drwhite/hs-gc-mine/hotspot/test/JTwork/closed/runtime/AppCDS/SharedArchiveConsistency.jtr>:
>>         SharedArchiveConsistency
>>
>>     Plus a bunch of tests that are labelled "ignored".
>>
>>
>

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