Description of problem:
RHEL8.1 java-11 performance regression vs RHEL 7.6 java-11, using the specjbb2005 benchmark.

There are some CVE mitigation differences, would like to try measuring the older java-11 on my RHEL 8.1 environment if it is possible to force install the el7 rpm.


Version-Release number of selected component (if applicable):

RHEL 8.1 update 2.4
  java-11-openjdk-11.0.5.10-2.el8_1.x86_64  
  4.18.0-147.3.1.el8_1.x86_64
microcode	: 0x2000064	(pre Nov 19)
vulnerabilities/itlb_multihit:KVM: Mitigation: Split huge pages
vulnerabilities/l1tf:Mitigation: PTE Inversion; VMX: conditional cache flushes, SMT disabled
vulnerabilities/mds:Mitigation: Clear CPU buffers; SMT disabled
vulnerabilities/meltdown:Mitigation: PTI
vulnerabilities/spec_store_bypass:Mitigation: Speculative Store Bypass disabled via prctl and seccomp
vulnerabilities/spectre_v1:Mitigation: usercopy/swapgs barriers and __user pointer sanitization
vulnerabilities/spectre_v2:Mitigation: Full generic retpoline, IBPB: conditional, IBRS_FW, RSB filling
vulnerabilities/tsx_async_abort:Mitigation: Clear CPU buffers; SMT disabled

RHEL 7.6 GA
  java-11-openjdk-11.0.ea.28-7.el7.x86_64
  3.10.0-957.el7.x86_64
microcode	: 0x200004d	GA ~Nov 2018
vulnerabilities/l1tf:Mitigation: PTE Inversion; VMX: SMT disabled, L1D conditional cache flushes
vulnerabilities/meltdown:Mitigation: PTI
vulnerabilities/spec_store_bypass:Mitigation: Speculative Store Bypass disabled via prctl and seccomp
vulnerabilities/spectre_v1:Mitigation: Load fences, __user pointer sanitization
vulnerabilities/spectre_v2:Mitigation: IBRS (kernel)


Steps to Reproduce:

specjbb2005 benchmark, using the following params:
input.jvm_instances=1
input.starting_number_warehouses=4
input.increment_number_warehouses=4
input.ending_number_warehouses=8
input.ramp_up_seconds=120
input.measurement_seconds=120

Running 6 JBB instances on the same baremetal 32c Skylake, looking at total throughput across all instances. Switching between RHEL 8.1 and 7.6 disk for the comparison. 

Actual results:
8.1 / java-11-openjdk-11.0.5.10-2.el8_1
total WH4	1,188,621	
total WH8	1,404,064	


7.6 / java-11-openjdk-11.0.ea.28-7.el7
total WH4	1,383,549
total WH8	1,537,329

regression of 9-16%


Additional info:
numactl pinned results show even higher regression (numabalancing improvements reduce pinning impacts on RHEL8.x):
-- pinned 3 JBB instances on each numa node -- 
8.1: 
total WH4	1,216,123
total WH8	1,448,118

7.6:
total WH4	1,440,882
total WH8	1,730,265