Answer :
The changes would be necessary so that a process waiting to acquire a mutex lock would be blocked and placed into a waiting queue is: Spinlocks.
What is spinlock?
Spinlock can be defined as the process of enabling a thread to wait while looking for lock that are available.
Spinlock is important as it enable thread to partition processor based on their needs so as to make it possible for thread waiting for spinlock to make use of one processor while other threads can as well run on other processor without hindering or interrupting one another.
Inconclusion the changes would be necessary so that a process waiting to acquire a mutex lock is: Spinlocks.
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