Receive 1．  napi && none napi 讲网络收报过程,必然要涉及到网卡收报模型发展历史.总体上看,网络收报过经历了如下发展过程: 轮询 ---à 中断 ---à 中断期间处理多帧 ---à定时器驱动的中断 ---à中断加轮询 轮询:最早出现的收报方式,易于理解和编程,核心思想是cpu不断读取网卡指定寄存器来判断是否有数据达到netdevice,从而进一步决定是否启动收报线程.轮询的特点是低流量时浪费cpu资源,cpu负载过高,高流量时表现较好. 中断:每当有一个数据帧…

This 125 kHz RFID reader http://www.serasidis.gr/circuits/RFID_reader/125kHz_RFID_reader.htm http://www.serasidis.gr/circuits/RFID_reader/images/125kHz_RFID_reader_schem.GIF I will try to explain with simple words how the RFID works. The ATtiny13 use…

VNF网络性能提升解决方案及实践 2016年7月 作者:    王智民 贡献者:     创建时间:    2016-7-20 稳定程度:    初稿 修改历史 版本 日期 修订人 说明 1.0 2016-7-20 王智民 初稿                 目录 1    引言    1 1.1    编写目的    1 1.2    背景    1 2    SDN    1 2.1    SDN核心思想    1 2.2    网络虚拟化    4 3    NFV    7 3.1  …

Introduction============ This document describes a set of complementary techniques in the Linuxnetworking stack to increase parallelism and improve performance formulti-processor systems. The following technologies are described: RSS: Receive Side Sc…

A computer-implemented system and method for a lock-less, zero data copy messaging mechanism in a multi-core processor for use on a modem in a telecommunications network are described herein. The method includes, for each of a plurality of processing…

/** * struct sock - network layer representation of sockets * @__sk_common: shared layout with inet_timewait_sock * @sk_shutdown: mask of %SEND_SHUTDOWN and/or %RCV_SHUTDOWN * @sk_userlocks: %SO_SNDBUF and %SO_RCVBUF settings * @sk_lock: synchronizer…

扩展Linux网络栈 来自Linux内核文档.之前看过这篇文章,一直好奇,问什么一条网络流会固定在一个CPU上进行处理,本文档可以解决这个疑问.为了更好地理解本文章中的功能,将这篇文章穿插入内. 简介 本文的描述了Linux网络栈中的一组补充技术,用于增加多处理器系统的并行性和提高性能. 描述的结束为: RSS: Receive Side Scaling RPS: Receive Packet Steering RFS: Receive Flow Steering Accelerated Rec…

蓝牙BLE实用教程 Bluetooth BLE 欢迎使用 小书匠(xiaoshujiang)编辑器,您可以通过 设置 里的修改模板来改变新建文章的内容. 1.蓝牙BLE常见问答 Q: Smart Ready 和 Smart 以及传统蓝牙之间是什么关系? Q: 双模(dual-mode)和单模(single-mode)有什么区别? Q: There is a confusion between Server-Client vs Master-Slave vs Central-Peripheral.…

原文地址: https://software.intel.com/en-us/articles/enhancing-the-scalability-of-memcached-0 1 Introduction - Memcached and Web Services Memcached is a Key-Value cache used by cloud and web service delivery companies, such as Facebook [1], Twitter [2], R…

http://blog.packagecloud.io/eng/2016/06/22/monitoring-tuning-linux-networking-stack-receiving-data/ Jun 22, 2016 • packagecloud Tags: packagecloud linux kernel networking optimization tuning monitoring TL;DR This blog post explains how computers runn…

https://www.coverfire.com/articles/queueing-in-the-linux-network-stack/ Queueing in the Linux Network Stack http://blog.jobbole.com/62917/ [A slightly shorter and edited version of this article appeared in the July 2013 issue of Linux Journal. Thanks…

1.前言 本文是对K64 datasheet 之ENET部分的功能描述,将对每个部分进行详细说明 2.Ethernet MAC frame formats MAC帧组成格式 (1)7字节前导码:如按最低位先传则为0x55 0x55 0x55 0x55 0x55 0x55: (2)起始帧定界符(SFD):如按最低位先传则为0XD5: (3)2个地址域:包括源MAC地址和目的MAC地址: (4)VLAN-tagged :可选,占4字节 (5)长度或类型域:代表有效负荷的长度或者类型,以太网802.3…

欢迎使用 小书匠(xiaoshujiang)编辑器,您可以通过 设置 里的修改模板来改变新建文章的内容. 1.蓝牙BLE常见问答 Q: Smart Ready 和 Smart 以及传统蓝牙之间是什么关系? Q: 双模(dual-mode)和单模(single-mode)有什么区别? Q: There is a confusion between Server-Client vs Master-Slave vs Central-Peripheral. I need a simplified exp…

How can you add extra hardware UARTs to a 32bit TMS470 ARM7-based microcontroller at zero cost? Solution: Designers can use the high-end timer (HET) peripheral found on all Texas Instruments ARM7-based, 32-bit TMS470 microcontrollers to implement add…

Congestion Avoidance in TCP Consequence of lack of congestion control When a popular resource is shared without regulation the result is always over-utilization With the introduction of TCP in 1983, users can write networking applications that requir…

14.1 网络设备驱动结构 网络协议接口层:硬件无关,标准收发函数dev_queue_xmit()和netif_rx();  注意,netif_rx是将接收到的数据给上层,有时也在驱动收到数据以后调用. 网络设备接口层,net_device,统一接口名称,使上层独立于具体硬件. 设备驱动功能层,实现net_device的各成员 物理层 在整个以太网架构里,有两个数据结构非常重要,即sk_buff和net_device,后面两节有说明. 还有一些与内核交互的函数,需要掌握,如netif_start…

不多说,直接上干货! 见suricata官网 https://suricata.readthedocs.io/en/latest/rules/index.html 一.Suricata的规则所放位置 下面,是我使用的SELKS里安装的Suricata默认自带规则. 见博客 Stamus Networks的产品SELKS(Suricata IDPS.Elasticsearch .Logstash .Kibana 和 Scirius )的下载和安装(带桌面版和不带桌面版)(图文详解) root@SE…

A method for optimizing the throughput of TCP/IP applications by aggregating user application data and consolidating multiple TCP/IP connection streams into a single optimized stream for delivery to a destination application. Optimization of the inte…

In one embodiment, a source device detects a packet flow that meets criteria for multi-path forwarding, and forwards a probe packet on a primary path from the source device to a destination device, the probe packet carrying an indication to cause a p…

https://www.cmrr.umn.edu/~strupp/serial.html#CONTENTS Introduction Chapter 1, Basics of Serial Communications What Are Serial Communications? What Is RS-232? Signal Definitions Asynchronous Communications What Are Full Duplex and Half Duplex? Flow Co…

https://datatracker.ietf.org/doc/rfc8684/?include_text=1 TCP Extensions for Multipath Operation with Multiple AddressesRFC 8684   Document Type   RFC - Proposed Standard (March 2020; No errata) Obsoletes RFC 6824 Was draft-ietf-mptcp-rfc6824bis (mptc…

proto socket 关联结构: { .type = SOCK_STREAM, .protocol = IPPROTO_TCP, .prot = &tcp_prot, .ops = &inet_stream_ops, .flags = INET_PROTOSW_PERMANENT | INET_PROTOSW_ICSK, }, { .type = SOCK_DGRAM, .protocol = IPPROTO_UDP, .prot = &udp_prot, .ops = &am…

[转]wpa_supplicant与wpa_cli之间通信过程 转自:http://blog.chinaunix.net/uid-26585427-id-4051479.html wpa_supplicant编译: 1. wpa_supplicant/Android.mk : -- wpa_cli -- wpa_supplicant -- libwpa_client.so 2. hostapd/Android.mk : -- hostapd_cli -- hostapd 从通信层次上划分,wpa…

接续前节. 7 PMD (Poll Mode Driver) A Poll Mode Driver (PMD) consists of APIs, provided through the BSD driver running in user space, to configure the devices and their respective queues. In addition, a PMD accesses the RX and TX descriptors directly with…

USART簡介與特性 NRZ標準資料格式(Mark/Space) 半雙工/全雙工 Synchronous 同步傳輸 CLOCK SKEW Asynchronous 非同步傳輸 半/全雙工.同步/非同步 & Serial bus 示意圖 RS232 介面標準 RS-232電器與機械特性 RS-232訊號傳輸 STM32 USART介紹與特性 USART Block Diagram USART data frame & M bit 10種中斷 3個傳輸檢測標誌 Tx傳送器 資料的傳送 傳送器的…

1 前言 STM32有强大的固件库,绝大部分函数都可以有库里面的函数组合编写.固件库可以到ST官网(www.st.com)上下载,也可以搜索“STM32 固件库 v3.5”下载到固件库.本文章就是基于固件库来编写有关串口的输入输出函数.由于博主的知识水平有限,目前仅仅是将程序的思路和实现给出,具体到函数的执行效率.代码的简化方面未进行深入探讨.如果有兴趣的同学可以联系我,我们可以一起探讨一下. 2 STM32固件库 有关固件库的详细介绍,在emouse 思·睿 技术博客里有较为详细的解释(详见h…

Beej's Guide to Network Programming Using Internet Sockets Brian "Beej Jorgensen" Hallbeej@beej.us Version 3.0.15July 3, 2012 Copyright © 2012 Brian "Beej Jorgensen" Hall Contents 1. Intro 1.1. Audience 1.2. Platform and Compiler 1.3. …

I test multicast on openstack. I use external Router in this test. Openstack Environment: Havana (ML2 + OVS)    Test Environment: VM1 is in Vlan 850. VM2,VM3,VM4 are in Vlan 820. VM2 and VM3 are on the same compute node ci91szcmp003 , VM1 and VM4 are…

转自:https://blog.csdn.net/dosthing/article/details/80384541 前言 网络编程是程序连接网络拓展的基础,尤其是在物联网.互联网加等概念火热的当下,网络编程能力体现了一个程序员能否具有大型程序的开发能力.在实际应用中,往往需要显示目前系统的实时网速等信息,当然获取网速等信息的软件方法很多,但是用小几行代码,并可移植性好的方法却不多,这里介绍如何通过Linux的proc文件系统进行实时获取网卡收发速率. 原理简介 Linux提供的LKM机制可以使…

Overview of HAL drivers The HAL drivers were designed to offer a rich set of APIs and to interact easily with the application upper layers.Each driver consists of a set of functions covering the most common peripheral features.The development of each…