Concurrent marking of root objects

[raell at web.de]

Hi Zhengyu, 

cool. Thank you very much for the information. 

Regards
Ralph 
 
 

On 5/29/20 8:47 PM, zgu at redhat.com wrote: 
> Hi Ralph,
>
> I am working on moving some root marking into concurrent phase.
> https://bugs.openjdk.java.net/browse/JDK-8245961
> 
> ZGC also has concurrent thread stack marking
> (https://github.com/openjdk/zgc/commit/d9abea0cc6df148a3781600dfe6bfcc1a4a1873c#diff-a6bc76531aecc703472f887d4e162b94[https://github.com/openjdk/zgc/commit/d9abea0cc6df148a3781600dfe6bfcc1a4a1873c#diff-a6bc76531aecc703472f887d4e162b94]),
> hopefully, will mature in near future.
> 
> After that, remaining STW roots are quite small.

> -Zhengyu

> On 5/28/20 8:17 PM, raell at web.de wrote:
>> Hi,
>>
>> this isn't a real question, but more kind of an idea. After Shenandoah has made evacuation
>> of root objects concurrent in JDK 14, I wonder if it shouldn't be possible to mark root
>> objects concurrently, as well? To my understanding, the SATB barrier is already able
>> to detect reference changes on root objects. So, at least from the SATB barrier point of view,
>> it shouldn't be much of a difference if root objects are marked in a STW phase or concurrently.
>>
>> Regards
>> Ralph
>>