【摘要】 嵌入式系统是资源受限的系统。在分析Linux对嵌入式系统网络实时性支持不足的基础上,提出了基于零拷贝技术的网络实时性能优化策略。采用虚拟内存操作方法消除内核空间和用户空间之间的数据拷贝,来减轻CPU的通信负担.用静态分配网络缓冲区代替原系统的动态分配。本文还提出了一种定长的分包机制,既可降低网络传输的延迟时间,同时也保证了1个数据包不会跨越2个页面的问题。实验结果表明:经过优化的网络系统的实时性能得到了明显的改善。更多还原

【Abstract】 Embedded system is usually resource limited in terms of processing power, memory and power consumption,thus embedded system should be designed to make the best of limited resources. After the lack of real-time performance in Linux network for embedded system is analyzed, real-time performance optimization methods based on zero-copy mechanism are proposed. In order to decrease the processing overhead,page remapping mechanism to eliminate the data copies between the user space and the kernel space is used.On the other hand, network buffer pre-allocated is provided to substitute the dynamic buffer allocating in original Linux. And also a fragmentation method is proposed, which can result in lower overall latencies and prevent a packet crossing the page boundary.The experimental result shows that the proposed method can improve the transmission efficiency obviously.更多还原