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

[Daniel D. Daugherty]

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...

Thumbs up!

Dan

>
>
> Thanks,
>
> Patricio