RFR(XS): 8001424: G1: Rename certain G1-specific flags

Bengt Rutisson bengt.rutisson at oracle.com
Wed Dec 19 22:30:31 PST 2012


Hi again John,

I realized that I was a bit too fast with my comment about using 
ObsoleteFlag. Your code is aliasing the old names for the new ones which 
is something the obsolete flag management does not do.

But on the other hand, do we really want to do this? These are all 
experimental flags and we are pushing this change to a major release, 
JDK8. Personally I don't think it is worth supporting the old names.

Bengt

On 12/20/12 5:45 AM, Bengt Rutisson wrote:
>
> Hi John,
>
> This looks good. But I think that instead of your change in 
> arguments.cpp you could make use of the obsolete_jvm_flags list that 
> exist in the same file. I think that is intended for exactly this 
> purpose. Accepting a removed flag name for a little while. The nice 
> thing about it it that you specify how long you will accept the old name.
>
> static ObsoleteFlag obsolete_jvm_flags[] = {
>   { "UseTrainGC",                    JDK_Version::jdk(5), 
> JDK_Version::jdk(7) },
>
> If you use this you also have to remove the old flag names from 
> globals.hpp.
>
> Bengt
>
>
> On 12/20/12 1:56 AM, John Cuthbertson wrote:
>> Hi Everyone,
>>
>> Some flag name changes suggested by the JVM performance team based 
>> upon feedback they have received. The webrev can found at: 
>> http://cr.openjdk.java.net/~johnc/8001424/webrev.0/
>>
>> Basically the changes are those listed in the webrev:
>>
>> G1DefaultMinNewGenPercent is being replaced by G1NewSizePercent
>> G1DefaultMaxNewGenPercent is being replaced by G1MaxNewSizePercent
>> G1OldCSetRegionLiveThresholdPercent is being replaced by 
>> G1MixedGCLiveThresholdPercent
>>
>> Thanks,
>>
>> JohnC
>

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