ADDITIONAL SYSTEM INFORMATION :
centos7

A DESCRIPTION OF THE PROBLEM :
8 core cpu cores/16 threads
high load (~7), high memory allocation rate
64G memory, 16G heap (size is not the problem, after gc allocation going down to <10%)

1day/jdk15.02 (default ParallelGCThreads=10, ConcGCThreads=2)
10181 garbage collections
414 Allocation Stall
sum allocation stall time: 72s
jobs executed: 1.98M

1day/jdk16 (default ParallelGCThreads=10, ConcGCThreads=2)
10118 garbage collections
94180 Allocation Stall
sum allocation stall time: 10335s

1day/jdk16 (optimized, ParallelGCThreads=10, ConcGCThreads=6)
10353 garbage collections
3566 Allocation Stall
sum allocation stall time: 152s
jobs executed: 1.96M


REGRESSION : Last worked in version 15.0.2


FREQUENCY : often