This is a paragraph from Operating System Concepts, 9th edition by Silberschatz et al: The percentage of times that the page number of interest is found in the TLB is called the hit ratio. An 80-percent hit ratio, for example, means that we find the desired page number in the TLB 80 percent of the … Read more
This is done to exploit the principle of locality; spatial locality to be precise. This principle states that the data bytes which lie close together in memory are likely to be referenced together in a program. This is immediately apparent when accessing large arrays in loops. However, this is not always true (e.g. pointer based … Read more
Let’s consider a constant stream of cache requests with a cache capacity of 3, see below: If we just consider a Least Recently Used (LRU) cache with a HashMap + doubly linked list implementation with O(1) eviction time and O(1) load time, we would have the following elements cached while processing the caching requests as … Read more
Your definition of a “conflict miss” is a bit unhelpful. A conflict miss occurs when a block is needed which existed in the cache before, but was evicted in favor of another block that had to be mapped to the same slot. In your example, the accesses to 13 and 25 are unique, so they … Read more
I noticed this new wordpress version I’m running has a “Endurance Cache” option at the bottom of the “Settings > General” page. That is caching all of the changes I’m doing on css. So whenever I update something the changes don’t reflect on the browser instantaneously. I’m wondering if that’s wordpress native or if I … Read more
Summary (TL;DR) Updated June 3rd, 2017 Redis is more powerful, more popular, and better supported than memcached. Memcached can only do a small fraction of the things Redis can do. Redis is better even where their features overlap. For anything new, use Redis. Memcached vs Redis: Direct Comparison Both tools are powerful, fast, in-memory data … Read more