Question

If a processor uses a 4-way set-associative cache with an LRU replacement policy, which memory block is evicted when a new block maps to a full set where every block has been accessed in the order 3, 1, 2, 0?

Accepted Answer

In a 4-way set-associative cache, the cache is divided into sets, each containing four slots called blocks that hold memory data. A set-associative cache uses a replacement policy to decide which existing block to remove when a new memory block needs to be loaded into a full set. The Least Recently Used (LRU) policy identifies the block that has gone the longest time without being accessed and evicts it to make room for the new block. The provided access sequence 3, 1, 2, 0 represents the relative time since each block was last used, where 3 is the most recently accessed block and 0 is the least recently accessed block. Because block 0 has the lowest value in this sequence, it is the one that has not been accessed for the longest time. Therefore, block 0 is the victim that will be evicted from the cache to accommodate the new incoming memory block.

Home → All Courses → Engineering and Technology Courses → Computer Engineering → Flashcard

If a processor uses a 4-way set-associative cache with an LRU replacement policy, which memory block is evicted when a new block maps to a full set where every block has been accessed in the order 3, 1, 2, 0?

In a 4-way set-associative cache, the cache is divided into sets, each containing four slots called blocks that hold memory data. A set-associative cache uses a replacement policy to decide which existing block to remove when a new memory block needs to be l....