DFS-prefetch-benchmark

Simple benchmark to test effectiveness of prefetching in the mark-phase of garbage collectors.

lscpu

Architecture:                    x86_64
CPU op-mode(s):                  32-bit, 64-bit
Byte Order:                      Little Endian
Address sizes:                   46 bits physical, 48 bits virtual
CPU(s):                          36
On-line CPU(s) list:             0-35
Thread(s) per core:              2
Core(s) per socket:              18
Socket(s):                       1
NUMA node(s):                    1
Vendor ID:                       GenuineIntel
CPU family:                      6
Model:                           85
Model name:                      Intel(R) Xeon(R) Platinum 8124M CPU @ 3.00GHz
Stepping:                        4
CPU MHz:                         1505.787
BogoMIPS:                        5999.99
Hypervisor vendor:               KVM
Virtualization type:             full
L1d cache:                       576 KiB
L1i cache:                       576 KiB
L2 cache:                        18 MiB
L3 cache:                        24.8 MiB
NUMA node0 CPU(s):               0-35
Vulnerability Itlb multihit:     KVM: Vulnerable
Vulnerability L1tf:              Mitigation; PTE Inversion
Vulnerability Mds:               Vulnerable: Clear CPU buffers attempted, no microcode; SMT Host state unknown
Vulnerability Meltdown:          Mitigation; PTI
Vulnerability Spec store bypass: Vulnerable
Vulnerability Spectre v1:        Mitigation; usercopy/swapgs barriers and __user pointer sanitization
Vulnerability Spectre v2:        Mitigation; Full generic retpoline, STIBP disabled, RSB filling
Vulnerability Srbds:             Not affected
Vulnerability Tsx async abort:   Not affected
Flags:                           fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss ht syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon rep_good nopl xtopolog
                                 y nonstop_tsc cpuid aperfmperf tsc_known_freq pni pclmulqdq monitor ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lah
                                 f_lm abm 3dnowprefetch invpcid_single pti fsgsbase tsc_adjust bmi1 avx2 smep bmi2 erms invpcid mpx avx512f avx512dq rdseed adx smap clflushopt clwb avx512cd avx512bw avx512vl xsaveo
                                 pt xsavec xgetbv1 xsaves ida arat pku ospke

Eager (object enqueueing)

 Performance counter stats for './a.out':

         939148124      cache-references                                            
         715013232      cache-misses              #   76.134 % of all cache refs    
      103334874546      cycles                                                      
       11349140492      instructions              #    0.11  insn per cycle         
        2686988208      branches                                                    
             32922      faults                                                      
                 0      migrations                                                  

      29.921045550 seconds time elapsed

      29.859988000 seconds user
       0.060080000 seconds sys

Lazy (edge enqueueing)

Performance counter stats for './a.out lazy':

         968644071      cache-references                                            
         738536116      cache-misses              #   76.244 % of all cache refs    
      128893216274      cycles                                                      
       12052674761      instructions              #    0.09  insn per cycle         
        2586785613      branches                                                    
             32921      faults                                                      
                 0      migrations                                                  

      37.301091162 seconds time elapsed

      37.215494000 seconds user
       0.084071000 seconds sys

Eager prefetch (object enqueueing + prefetch)

Performance counter stats for './a.out prefetch':

         758815118      cache-references                                            
         581584323      cache-misses              #   76.644 % of all cache refs    
       75534973743      cycles                                                      
       33427897695      instructions              #    0.44  insn per cycle         
        6778701607      branches                                                    
             33122      faults                                                      
                 0      migrations                                                  

      21.878402555 seconds time elapsed

      21.801422000 seconds user
       0.076117000 seconds sys

Lazy prefetch (edge enqueueing + prefetch)

Performance counter stats for './a.out prefetch lazy':

         766396384      cache-references                                            
         585606035      cache-misses              #   76.410 % of all cache refs    
       53974221073      cycles                                                      
       33423314496      instructions              #    0.62  insn per cycle         
        6778155652      branches                                                    
             33021      faults                                                      
                 0      migrations                                                  

      15.644569534 seconds time elapsed

      15.523668000 seconds user
       0.120214000 seconds sys