RFR 8204947: Port ShenandoahTaskTerminator to mainline and make it default
zgu at redhat.com
Thu Nov 29 14:41:08 UTC 2018
Updated version also passed submit tests.
On 11/28/18 10:26 PM, Zhengyu Gu wrote:
> Webrev updated to suppress multiple copy constructors and assignment
> operators warnings on Window.
> Webrev: http://cr.openjdk.java.net/~zgu/JDK-8204947/webrev.01/
> On 11/28/18 2:08 PM, Zhengyu Gu wrote:
>> ShenandoahTaskTerminator is based on Google's work stealing protocol,
>> described in paper . The implementation diverges in a way to
>> emphasize termination latency vs. power efficiency (see comments in
>> code for details).
>> Shenandoah switched to ShenandoahTaskTerminator as default terminator,
>> shortly after it was implemented, and has been very stable since.
>> On performance side, it showed better termination latency on almost
>> all tests/benchmarks I ran, comparing to ParallelTaskTerminator. As
>> the result, we (Shenandoah) purged fallback branches and uses it as
>> the sole task terminator.
>> This patch introduces a new experimental flag "UseOWSTTaskTerminator"
>> (default: true), and switches G1 and Parallel GC to use it as default
>> terminator. You can switch back to ParallelTaskTerminator with JVM
>> option "-XX:+UnlockExperimentalVMOptions -XX:-UseOWSTTaskTerminator"
>> I did not port it to CMS, as it is depreciated.
>> Bug: https://bugs.openjdk.java.net/browse/JDK-8204947
>> Webrev: http://cr.openjdk.java.net/~zgu/JDK-8204947/webrev.00/
>> hotspot_gc and vmTestbase_vm_gc on Linux 64.
>>  Understanding and improving JVM GC work stealing at the data
>> center scale (http://dl.acm.org/citation.cfm?id=2926706)
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