[sh/jdk8u] RFR [backport] 8232747: Shenandoah: Concurrent GC should deactivate SATB before processing weak roots

[Zhengyu Gu]

On 12/1/20 2:49 PM, Roman Kennke wrote:
> 
> 
> 
>> This is *not* straight forward backport, as sh/jdk8u has yet adopted 
>> parallel_cleaning() from upstream, which is too risky to backport, IMHO.
>>
>> The key point of this patch is that, we should deactivate SATB before 
>> processing weak roots.
>>
>> Original bug: https://bugs.openjdk.java.net/browse/JDK-8232747
>> Original patch: https://hg.openjdk.java.net/jdk/jdk/rev/ef2b75750838
>>
>> sh/jdk8u webrev: 
>> http://cr.openjdk.java.net/~zgu/shenandoah/JDK-8232747-8u/webrev.00/
>>
>> Test:
>>    hotspot_gc_shenandoah Linux x86_64 and x86_32
>>
> 
> Don't we also need:
> 
> +      set_has_forwarded_objects(false);
> 
I am assuming you are referring to the one in op_final_mark()? we don't 
have that branch anymore. I believe that branch is for dealing with 
piggyback ref update cycle.

-Zhengyu


> from the original patch?
> 
> Roman
>