linux os processor optimizations for OpenJDK performance enhancement

[David Holmes]

Redirecting to hotspot-dev mailing list, please drop jdk10-dev on future 
replies.

On 13/04/2017 9:39 AM, Ram Krishnan wrote:
> We are working on linux os processor specific optimizations centered around
> cache partitioning and better processor core thread(s) affinity for OpenJDK
> GC performance enhancement with the following benefits
> - throughput increase
> - minimizing tail latency for latency sensitive applications
> - superior isolation in a multi-tenant environment
>
> ​We have been looking at the G1GC code/documentation and performed some
> initial experiments. Based on this, what we understand is that STW events
> pause all application threads independent of which regions are being
> impacted by garbage collection. For example, if application thread "x" uses
> regions 1, 4, 5 and  garbage collection is working on regions 2 and 11,
> application thread "x" is paused during the STW event.

A stop-the-world event does stop all application threads (all 
JavaThreads in VM terminology) by using a safepoint.

I'll let the GC folks comment on the details wrt. G1 region management.

Cheers,
David

> Your expert opinion on this topic is much appreciated.
>