RFR 8231264: Implementation of JEP 374: Disable biased-locking and deprecate all flags related to biased-locking

[Patricio Chilano]

Hi Dan,

On 3/27/20 1:41 PM, Daniel D. Daugherty wrote:
> On 3/26/20 3:23 PM, Patricio Chilano wrote:
>> Hi all,
>>
>> Please review the following implementation for JEP 374: Disable and 
>> Deprecate Biased Locking.
>>
>> As already discussed we will change the default value for 
>> UseBiasedLocking to false. Deprecating the flags will also give more 
>> visibility to the change and should increase our changes to 
>> potentially get more feedback.  After a transition/evaluation period 
>> and based on collected evidence that will complement the results of 
>> our own benchmarks we can decide if we want to keep this feature or not.
>>
>> I modified test VMDeprecatedOptions.java to include the deprecated 
>> flags, except for the two diagnostic ones 
>> (PrintBiasedLockingStatistics, PrintPreciseBiasedLockingStatistics).
>>
>> Tested in mach5, tiers1-7 on all platforms (Linux-x64, macOS-x64, 
>> Windows-x64, Solaris-sparcv9).
>>
>> Let me know if there are more tests I should run.
>>
>> Bug:
>>   https://bugs.openjdk.java.net/browse/JDK-8231264
>>
>> Webrev:
>>   http://cr.openjdk.java.net/~pchilanomate/8231264/v1/webrev/
>
> src/hotspot/share/opto/c2_globals.hpp
>     No comments.
>
> src/hotspot/share/runtime/arguments.cpp
>     No comments.
>
> src/hotspot/share/runtime/globals.hpp
>     No comments.
>
> test/hotspot/gtest/oops/test_markWord.cpp
>     No comments.
>
> test/hotspot/jtreg/runtime/CommandLine/VMDeprecatedOptions.java
>     Is there a C2 specific test for checking deprecation of
>     PrintPreciseBiasedLockingStatistics and UseOptoBiasInlining?
>     I don't remember there being one, but I figured I would ask...
I didn't find any other test to check that besides VMDeprecatedOptions.java.

> Thumbs up!
Thanks for reviewing this Dan!


Patricio
> Dan
>
>>
>>
>> Thanks,
>>
>> Patricio
>