Host-side page victimizations can easily overflow the SSD internal buffer, which interferes I/O services of diverse user applications thereby degrading user-level experiences. To address this, we propose FastDrain, a co-design of OS kernel and flash firmware to avoid the buffer overflow, caused by page victimizations. Specifically, FastDrain can detect a triggering point where a near-future page victimization introduces an overflow of the SSD internal buffer. Our new flash firmware then speculatively scrubs the buffer space to accommodate the requests caused by the page victimization. In parallel, our new OS kernel design controls the traffic of page victimizations by considering the target device buffer status, which can further reduce the risk of buffer overflow. To secure more buffer spaces, we also design a latency-aware FTL, which dumps the dirty data only to the fast flash pages. Our evaluation results reveal that FastDrain reduces the 99th response time of user applications by 84%, compared to a conventional system.

中文翻译：

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FastDrain：消除 NVMe 存储堆栈中的页面损坏开销

主机端页面受害很容易使 SSD 内部缓冲区溢出，从而干扰不同用户应用程序的 I/O 服务，从而降低用户级体验。为了解决这个问题，我们提出了 FastDrain，这是一种 OS 内核和闪存固件的协同设计，以避免由页面受害引起的缓冲区溢出。具体来说，FastDrain 可以检测到一个触发点，即近期页面受害导致 SSD 内部缓冲区溢出。我们的新闪存固件然后推测性地清理缓冲区空间以适应由页面受害引起的请求。同时，我们新的操作系统内核设计通过考虑目标设备缓冲区状态来控制页面受害的流量，这可以进一步降低缓冲区溢出的风险。为了确保更多的缓冲空间，我们还设计了一个延迟感知 FTL，它只将脏数据转储到快速闪存页面。我们的评估结果表明，与传统系统相比，FastDrain 将用户应用程序的第 99 次响应时间缩短了 84%。