What is busy waiting?

When strict alteration is done there may take place situation like two processes setting their flag as true. Therefore both of the processes have equal priority to enter into the critical section. Consider that P_i is setting its flag as true in addition to that time a context switch take place so that P_j also sets it flag. Like a result both of them will try to get into the critical section. Therefore neither of them get into the critical section. This circumstance is known as busy waiting. To resolve this Peterson's solution is used.