RFR: 8257145: Performance regression with -XX:-ResizePLAB after JDK-8079555 [v2]

[Thomas Schatzl]

On Mon, 30 Nov 2020 09:53:16 GMT, Stefan Johansson <sjohanss at openjdk.org> wrote:

>> Dongbo He has updated the pull request incrementally with one additional commit since the last revision:
>> 
>>   store the "default size" for the PLAB in the PLABStats
>
> src/hotspot/share/gc/g1/g1CollectedHeap.cpp line 1410:
> 
>> 1408:   _archive_allocator(NULL),
>> 1409:   _survivor_evac_stats("Young", YoungPLABSize, YoungPLABSize * ParallelGCThreads, PLABWeight),
>> 1410:   _old_evac_stats("Old", OldPLABSize, OldPLABSize * ParallelGCThreads, PLABWeight),
> 
> I think you could leave those two unchanged and in the constructor for `G1EvacStats` do the multiplication with `ParallelGCThreads` for the desired value.

And rename the `default_plab_sz` parameter to `default_per_thread_plab_size` (and remove the `desired_net_plab_sz_` as suggested).

-------------

PR: https://git.openjdk.java.net/jdk/pull/1474