whaleshark> ./psum-run.pl
Summing 2^30 values
Threads Race Semaphore  Mutex   Adjacent memory acc     Spaced memory acc       Register acc    
1       3.34 33.85      32.66   3.47     3.71   0.51    
2       1.82 213.50     163.71  1.81     1.74   0.26    
3       1.24 271.09     276.85  1.23     1.24   0.17    
4       0.93 352.09     295.09  0.95     0.96   0.13    
5       1.12 359.80     344.55  1.11     1.06   0.15    
6       0.98 302.58     347.50  1.02     0.97   0.13