2. [4 points] Discuss the pros and cons of shared vs. private L2 caches for both single-threaded, multi-threaded, and multiprogrammed workloads, and reconsider them if having on-chip L3 caches2 3. 6 points] How do write buffers improve CPU performance? Are there any conditions under which write buffers can't help? Explain. 4. [6 points] (a) Explain the tradeoffs between virtually-addressed caches and physically-addressed caches. b) Why is it more difficult to have a virtually-addressed write-back cache? How can this limitation be overcome