8 Matching Annotations
  1. Apr 2022
    1. Repeated references to local variables are good because the compiler cancache them in the register file (temporal locality).. Stride-1 reference patterns are good because caches at all levels of the memoryhierarchy store data as contiguous blocks (spatial locality).

      重复使用 local variable 以及 stride-1 pattern 为什么是 cache-friendly 的?

    2. A copy of w is contained in the line if and only if the valid bit is setand the tag in the cache line matches the tag in the address of w.

      如何判断要读取的 w 在 cache line 里面?

    3. The process that a cache goes through of determining whether a request is ahit or a miss and then extracting the requested word consists of three steps: (1) setselection, (2) line matching, and (3) word extraction.

      process 请求内存,有哪三个步骤?

  2. Mar 2022
    1. Restrictive placement policies of this kind lead to a type of miss known asa conflict miss, in which the cache is large enough to hold the referenced dataobjects, but because they map to the same cache block, the cache keeps missing.

      如何理解 conflict miss?

    2. When the size of the working set exceedsthe size of the cache, the cache will experience what are known as capacity misses.

      什么是 capacity miss?

    3. For caches high in the memory hierarchy (close tothe CPU) that are implemented in hardware and where speed is at a premium,this policy is usually too expensive to implement because randomly placed blocksare expensive to locate.

      cache 等级高的 memory 为什么不要实现最灵活的 placement policy?

    4. The decision about which block to replace is governed by the cache’s replacementpolicy.

      当 cache misses 发生的时候,需要做什么事情,有哪些方式?

    5. a program needs a particular data object d from level k + 1, it first looksfor d in one of the blocks currently stored at level k. If d happens to be cachedat level k, then we have what is called a cache hit.

      什么是 cache hits?什么是 cache misses?