Measuring semop() +1 operations without undo
average over 10000 operations
number of operations per second: 35421.7
clock secs:2.82313e-05(=28.2313 usecs)  cpu secs:2.8e-05(=28 usecs)

Measuring semop() -1 operations without undo
average over 10000 operations
number of operations per second: 35197.3
clock secs:2.84113e-05(=28.4113 usecs)  cpu secs:2.9e-05(=29 usecs)

Measuring semop() +1 operations with undo
average over 10000 operations
number of operations per second: 24320.1
clock secs:4.11183e-05(=41.1183 usecs)  cpu secs:4.1e-05(=41 usecs)

Measuring semop() -1 operations with undo
average over 10000 operations
number of operations per second: 24348.5
clock secs:4.10703e-05(=41.0703 usecs)  cpu secs:4.1e-05(=41 usecs)