1. 平均内存引用时间 T = average memory reference time m = miss ratio = 1 - (hit ratio) Tm = time to make a main memory access when there is a miss (or, with multi-level cache, average memory reference time for the next-lower cache) Th =  the latency: the tim…

Cache replacement policies - Wikipedia https://en.wikipedia.org/wiki/Cache_replacement_policies Cache replacement policies From Wikipedia, the free encyclopedia     Jump to navigationJump to search This article is about general cache algorithms. For…

LRU(Least Recently Used)算法是缓存技术中的一种常见思想,顾名思义,最近最少使用,也就是说有两个维度来衡量,一个是时间(最近),一个频率(最少).如果需要按优先级来对缓存中的K-V实体进行排序的话,需要考虑这两个维度,在LRU中,最近使用频率最高的排在前面,也可以简单的说最近访问的排在前面.这就是LRU的大体思想. 在操作系统中,LRU是用来进行内存管理的页面置换算法,对于在内存中但又不用的数据块(内存块)叫做LRU,操作系统会根据哪些数据属于LRU而将其移出内存而腾出空间…

C++ Core Guidelines September 9, 2015 Editors: Bjarne Stroustrup Herb Sutter This document is a very early draft. It is inkorrekt, incompleat, and pµøoorly formatted. Had it been an open source (code) project, this would have been release 0.6. Copy…

http://docs.oracle.com/cd/E13222_01/wls/docs81/ConsoleHelp/jdbc_connection_pools.html#1106016 JDBC Connection Pools [Attributes and Console Screen Reference for JDBC Connection Pools] The following sections explain how to configure and manage JDBC co…

前言 Lab一做一晚上,blog一写能写两天,比做Lab的时间还长( 这篇博文是半夜才写完的,本来打算写完后立刻发出来,但由于今天发现白天发博点击量会高点,就睡了一觉后才发(几十的点击量也是点击量啊T_T).... 我个人计划采用bottom-up的方式,用两篇blog配合源码讲解xv6的文件系统. xv6对文件系统的架构做出了如下的分层: 我个人倾向于将设备驱动程序也加入到文件系统的架构中,因此最后形成的架构图如下: 本篇blog讲解首先谈了谈我个人对文件系统的见解,随后讲解xv6的存储介质层…

About Cache Eviction Algorithms A cache eviction algorithm is a way of deciding which element to evict when the cache is full. In Ehcache , the memory store and the off-heap store might be limited in size. When these stores get full, elements are evi…

cache 1.why The existence of cache is based on a mismatch between the performance characteristics of core components of computing architectures, namely that bulk storage cannot keep up with the performance requirements of the CPU and application proc…

Machine Learning Algorithms Study Notes 高雪松 @雪松Cedro Microsoft MVP 本系列文章是Andrew Ng 在斯坦福的机器学习课程 CS 229 的学习笔记. Machine Learning Algorithms Study Notes 系列文章介绍 2    Supervised Learning    3 2.1    Perceptron Learning Algorithm (PLA)    3 2.1.1    PLA --…

http://blog.sina.com.cn/s/blog_6472c4cc0102duzr.html 处理器微架构访问Cache的方法与访问主存储器有类似之处.主存储器使用地址编码方式,微架构可以地址寻址方式访问这些存储器.Cache也使用了类似的地址编码方式,微架构也是使用这些地址操纵着各级Cache,可以将数据写入Cache,也可以从Cache中读出内容.只是这一切微架构针对Cache的操作并不是简单的地址访问操作.为简化起见,我们忽略各类Virtual Cache,讨论最基础的Cach…