Consider a block with 8 threads

executing a section of code before

reaching a barrier. The

threads require the following amount of

time (in micro seconds) to execute the

sections: 2.0.

2.3, 3.0, 2.8, 2.4, 1.9, 2.6, 2.9 and spend

the rest of their time waiting for the

barrier. What

percentage of the threads' summed up

execution times is spent waiting for the

barrier?