如今的计算机架构中CPU和main memory的访问速度的差异是很大的,解决这一瓶颈有这么几种形式: RAM硬件设计的改善(速度和并行) Memory controller设计 CPU caches 给设备用的Direct memory access(DMA) 2 Commodity Hardware Today 大众架构 Figure 2.1: Structure with
非易失性内存Non-volatile memory (NVM) 操作系统不变,DRAM换成NVM也白搭。 Non-volatile memory: typically including NAND flash and solid-state drives (SSD) [不是硬盘吗?], and ROM chips such as EPROM (erasable programmable ROM) and EEPROM (electrically erasable programmable ROM). It can also be...
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...
global memory order可以是实际上存在于某个硬件实体上的顺序,例如CPU中的core0/core1(只有两个core)有自己的L1 cache,但是共享一个L2 cache,那么我们就可以认为global memory order就是L2 cache观察到的内存操作顺序。这里的global指的是core0/core1的范畴,如果我们引入其他DMA设备,这个global范畴就不再适用了。 ...
也就是说如果这个数据一开始在L1d、L2都不存在,那么就得先从main memory加载到L2,然后从L2加载到L1d,最后CPU才可以访问。 3.3 CPU Cache Implementation Details 3.3.1 Associativity 没看懂。略。 3.3.2 Measurements of Cache Effects keyword:cache prefetching、TLB cache miss ...
原文标题:Motherboard Chipsets and the Memory Map 原文地址:http://duartes.org/gustavo/blog/ [注:本人水平有限,只好挑一些国外高手的精彩文章翻译一下。一来自己复习,二来与大家分享。] 我打算写一组讲述计算机内幕的文章,旨在揭示现代操作系统内核的工作原理。我希望这些文章能对电脑爱好者和程序员有所帮助,特...
诊断视图下,执行display cpu-usage process[slotslot-id]和display cpu-usage processprocess-id命令,分别查看CPU占用率高的进程和组件,发现PROTO2进程、CACHE组件CPU占用率高,一般是单板报文上送过多导致。 诊断视图下,执行display cpu-defend statistics-all slot1命令查看单板的CP-CAR上送统计,连续查看CP-CAR上送...
(8)Memory latencies(内存操作延时) L1:缓存1 L2:缓存2 Main Mem:连续内存 Rand Mem:内存随机访问延时 Guesses 假如L1和L2近似,会显示“No L1 cache?” 假如L2和Main Mem近似,会显示“No L2 cache?” CPU上下文切换的次数和时间(context switch) ...
A CPU works through two main stages: Fetch-Execute Cycle and Decode-Execute Cycle. In the Fetch-Execute cycle, the processor fetches an instruction from memory, then decodes and executes that instruction before moving on to the next one until all instructions are complete. ...
Caches are small blocks of relatively fast RAM located close either directly inside or near the central processing unit which serves two functions: firstly, taking pressure off main memory reads and writes since caches operate at lower latency secondly speeding up. ...