1. 各种策略行为和优缺点 Read Through:CPU Read data Through(not Allocate) Cache to Main Memory. Read Allocate:CPU Read data from Main Memory and Allocate it in cache Write Through:CPU Write data Through Cache to Main Memory。 Write Back:CPU Write data Back to Cache. Write Allocate: CPU Wr...
我们应该知道程序是运行在 RAM之中,RAM 就是我们常说的DDR(例如 DDR3、DDR4等)。我们称之为main memory(主存)当我们需要运行一个进程的时候,首先会从Flash设备(例如,eMMC、UFS等)中将可执行程序load到main memory中,然后开始执行。在CPU内部存在一堆的通用寄存器(register)。如果CPU需要将一个变量(假设地址是A)...
比如从这种图中可以看到, 即使是l2 cache : main memory 也差不多是 1:10. 也就是说如果对于某一次访问 l2 cache 时间是 10ns, 然后内存访问的时间是100ns, 在没有优化前总的访问时间是 10 + 100 = 110ns, 在优化后访问的时间是 10/2 + 100 = 105 ns. 看起来对于延迟其实没有多大的提升. 只有5%...
A method for insuring data consistency between a plurality of individual processor cache memories and the main memory in a multi-processor cache memories and the main memory in a multi-processor computer system is provided which is capable of (1) detecting when one of a set of predefined data...
A processing system includes a cache memory system which receives an address and a memory request from a processor. Simultaneously, information is accessed responsive to the address from a main memory and from a cache memory. During access of the information from the main memory and cache memory...
数据在主存和缓存之间以固定大小的”块(block)”为单位传递,也就是每次从main memory读取的最小数据的单元。每个块的大小可能是4,8,16 Bytes或其他值,不同的CPU不尽相同,目前的x86 CPU cache line基本都是64 bytes。通常,人们更习惯称之为cache行,或者cache line。根据前一篇文章的描述,每个cache line除了包含...
cpu core -> l1 cache -> l2 cache -> l3 cache -> main memory L1缓存:几乎所有的现代多核CPU都会为每个核心提供独立的L1缓存,这是因为L1缓存设计用于提供极低的访问延迟。每个核心的L1缓存通常分为两部分:L1数据缓存(L1-D)和L1指令缓存(L1-I)。
Memory is split into a vast number of small sections known as cells. Each place or cell has a specific address that ranges from 0 to memory size – 1. There are three types of memory: Cache Memory, Primary Memory/Main Memory, and Secondary Memory....
12、Inclusive and exclusive caches 先讨论一个简单的内存读取,单核的. 如LDR X0, [X1], 假设X1指向main memory,且是cacheable. (1)、Core先去L1 cache读取,hit了,直接返回数据给Core (2)、Core先去L1 cache读取,miss了,然后会查询L2 cache,hit了,L2的cache数据会返回Core,还会导致这个cache line替换到L1...
cpu core -> l1 cache -> l2 cache -> l3 cache -> main memory L1缓存:几乎所有的现代多核CPU都会为每个核心提供独立的L1缓存,这是因为L1缓存设计用于提供极低的访问延迟。每个核心的L1缓存通常分为两部分:L1数据缓存(L1-D)和L1指令缓存(L1-I)。