做美剧盗版网站,国内购物网站案例分析,搭建个人小型服务器,宠物网站建设论文下面列出paramerter中和性能相关的几个以及他们的取值范围和默认值。InterruptThrottleRate范围#xff1a;100-100000 (0off, 1dynamic)默认#xff1a;0注#xff1a;不支持82542, 82543, 82545, 82544芯片RxDescriptors范围#xff1a;80-256 for 82542 and 82543-based…下面列出paramerter中和性能相关的几个以及他们的取值范围和默认值。InterruptThrottleRate范围100-100000 (0off, 1dynamic)默认0注不支持82542, 82543, 82545, 82544芯片RxDescriptors范围80-256 for 82542 and 82543-based adapters80-4096 for all other supported adapters默认:256RxIntDelay范围0-65535 (0off)默认0RxAbsIntDelay范围0-65535 (0off)默认128TxDescriptors范围80-256 for 82542 and 82543-based adapters80-4096 for all other supported adapters默认256TxIntDelay范围0-65535 (0off)默认64TxAbsIntDelay范围0-65535 (0off)默认64其中各种*IntDelay的单位是1.024 microseconds我们可以根据网卡的性能和cpu内存pci总线等不同来调整它们的值另外可以编译网卡驱动的时候修改编译选项NAPI和NO_NAPI。make CFLAGS_EXTRA-DCONFIG_E1000_NAPI我找到一个关于如何修改这些参数取值得例子不过是英文的怕翻译的不好还是放上来原文吧。A Sample ConfigurationSome example settings are described below. These numbers are for illustration purposes only. Foroptimal performance, the exact controller configuration is best determined through actualexperimentation.The discussion below assumes that software is optimizing for full-size frames of 1538 bytes.The calculations below make use of the following facts:•Gigabit Ethernet operates at 1.0 Gb/s or 1,000,000,000 bits per second. At this speed, the time required to transmit or receive a single bit (in other words, the bit-time) is 1.0 nanosecond.•A full-size Ethernet frame requires 1538 bytes (12,304 bits) of bandwidth:--8-byte preamble and start-of-frame delimiter--14-byte Ethernet header--1500-byte payload--4-byte FCS--12-byte inter-packet gap•The controller can transmit or receive a full-size frame every 12.3 microseconds or approximately 81,000 packets per second.Absolute TimersConfiguring the absolute timers is typically a matter of determining the desired interrupt rate or thedesired number of packets per interrupt. To receive approximately 3000 interrupts per second,software would configure the absolute timers to interrupt every 333 microseconds.Alternately, to receive approximately 50 packets per interrupt, the controller must interruptapproximately 1620 times per second (81,000 packets-per-second at 50 packets-per-interrupt).Software would then configure the absolute timers to interrupt every 617 microseconds.Packet TimersExperiments have shown that values between 20 and 40 microseconds work well for the packettimers.Software might set the packet timers to expire after 2 full-length packet-times, or approximately 25microseconds. The packet timers would then expire when throughput falls below about 333Mbps(two unused packet-times follow every packet arrival, so approximately one-third of the totalbandwidth is in use). At greater levels of utilization, the packet timers would likely chainrepeatedly until the one of the absolute timers expired.Interrupt Throttle TimerConfiguring the throttle timer is simply a question of determining the desired maximum interruptrate. As described earlier, software may realize better results by setting the throttle timer tointerrupt slightly more often than desired to reduce unnecessary latencies.For typical applications, software might configure the controller to interrupt no more than 5000times per second.Different operating systems and environments will be capable of sustaining different maximuminterrupt rates. Experiments have demonstrated that Microsoft Windows-based operating systemsperform best when the device interrupts between 4,000 and 12,000 times per second. Linux-basedoperating systems appear to perform best with an interrupt rate between 1,000 and 8,000 interruptsper second. Other operating systems will perform differently.Additional Tuning ConsiderationsThe example configuration described above will require modifications to suit the intendedenvironment. The following factors may influence the tuning of the interrupt moderationparameters:•The latency associated with scheduling an interrupt handler. Larger scheduling latenciesimply larger packet latencies. Lower interrupt delays may be required in these situationsto avoid overrun conditions and excessive per-packet delays.•The cost associated with handling an interrupt. In OS with low-cost interrupts, higher interrupt rates may be acceptable. In OS with high-cost interrupts, lower interrupt rates may be required.•The expected mixture of packet sizes. The preceding discussion assumes that software is optimizing for full-size frames. Optimizing for small packets or for a variety of packet sizes requires recalculating the expected packet rate.•The expected network utilization. High utilization implies high traffic rates, which makes the controller more susceptible to overrun conditions if it delays interrupts too long.
