Measuring semop() +1 operations without undo
average over 10000 operations
number of operations per second: 46126.5
clock secs:2.16795e-05(=21.6795 usecs)  cpu secs:2.1e-05(=21 usecs)

Measuring semop() -1 operations without undo
average over 10000 operations
number of operations per second: 46500.4
clock secs:2.15052e-05(=21.5052 usecs)  cpu secs:2.2e-05(=22 usecs)

Measuring semop() +1 operations with undo
average over 10000 operations
number of operations per second: 41364.9
clock secs:2.41751e-05(=24.1751 usecs)  cpu secs:2.4e-05(=24 usecs)

Measuring semop() -1 operations with undo
average over 10000 operations
number of operations per second: 41477.4
clock secs:2.41095e-05(=24.1095 usecs)  cpu secs:2.4e-05(=24 usecs)