Effective cache replacement policy for packet processing cache
Effective cache replacement policy for packet processing cache
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DOI：
10.1002/dac.4526
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发表时间：
2020-07
影响因子：
2.1
通讯作者：
Hayato Yamaki
中科院分区：
文献类型：
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作者：
Hayato Yamaki
随着互联网流量的爆炸式增长，提高核心路由器的吞吐量和能量效率是未来互联网的一个重要问题。核心路由器中的三进制内容可寻址存储器（TCAM）由于其低操作频率和功耗操作而会显著降低其吞吐量和能量效率。为了提高核心路由器的吞吐量和能效，可以潜在地使用分组处理缓存（PPC）。PPC可以通过将TCAM查找结果存储在快速且低能耗的高速缓存中并重用它们来处理后续数据包，从而减少TCAM访问的次数。为了提高PPC性能，重要的是减少PPC未命中的数量。然而，由于其容量小，最先进的PPC的PPC未命中率仍然很高。在这项研究中，我们提出了一个有效的缓存替换策略，称为电梯缓存（ELC），以提高PPC的未命中率。我们的仿真结果表明，与4路最近最少使用（LRU）和4路ELC相比，可以低硬件成本实现的8路ELC分别将PPC未命中次数减少了17.1%和5.67%。因此，与传统PPC相比，8路ELC可以实现1.21倍的吞吐量（560 Gbps），同时消耗83%的能源。
Owing to the explosive increase in Internet traffic, increasing the throughput and energy efficiency of core routers is an important issue for future internet. Accessing the ternary content addressable memory (TCAM) in a core router can significantly degrade its throughput and energy efficiency owing to its low operating frequency and power consuming operations. To improve the throughput and energy‐efficiency of core routers, packet processing caches (PPCs) can be potentially used. PPCs can reduce the number of TCAM accesses by storing the TCAM lookup results in a fast and low‐energy cache memory and reusing them to process subsequent packets. To enhance the PPC performance, it is important to reduce the number of PPC misses. However, the PPC miss rate of the state‐of‐the‐art PPC is still high owing to its small capacity. In this study, we propose an effective cache replacement policy, called elevator cache (ELC) to improve the PPC miss rate. Our simulation results showed that the 8‐way ELC, which can be implementable at low hardware cost, reduced the number of PPC misses by 17.1% and 5.67% in comparison to the 4‐way least recently used (LRU) and the 4‐way ELC, respectively. Consequently, it was found that the 8‐way ELC can achieve a 1.21 times higher throughput (560 Gbps) while consuming 83% energy in comparison to conventional PPCs.