RFR: 8187809: UseMembar should be set true and deprecate the flag

[Daniel D. Daugherty]

On 11/8/17 3:52 PM, Robbin Ehn wrote:
> Hi,
>
> I forgot to say, UseMembar have been tested heavily on our supported 
> platforms.
> This particular changeset just passed sanity test of tier 1-2.
>
> Thanks, Robbin
>
> On 2017-11-08 21:48, Robbin Ehn wrote:
>> Hi all, please review!
>>
>> This patch set the default technique for reading thread state to 
>> memory barriers instead of using the asymmetric dekker 
>> synchronization on all platforms. We also deprecate the option and 
>> starting the removal process. There have been discussion with people 
>> involved in all platforms and we will have another discussion before 
>> obsoleting the flag to make sure no issue have been found.
>>
>> More info in CSR:
>> https://bugs.openjdk.java.net/browse/JDK-8187812
>>
>> Bug:
>> https://bugs.openjdk.java.net/browse/JDK-8187809
>>
>> Code:
>> http://cr.openjdk.java.net/~rehn/8187809/webrev/

src/hotspot/cpu/ppc/globals_ppc.hpp
src/hotspot/cpu/s390/globals_s390.hpp
src/hotspot/cpu/sparc/globals_sparc.hpp
src/hotspot/cpu/x86/globals_x86.hpp
     No comments.

src/hotspot/share/runtime/arguments.cpp
     No comments on your change.
     The existing inconsistent indents in those columns are annoying.

Thumbs up.

Dan


>>
>> Thanks, Robbin