UQP: Re-Mapped NVMe Queue Path for Handling Urgent I/O Requests

Recently, Most consumer electronics devices employ flash storage as their main storage, and to fully exploit the storage performance, the multi-queue-based NVMe device driver is being used in high-end devices. Thanks to its multi-queue architecture, the NVMe device driver can handle multiple I/O requests in parallel. However, this benefit may largely be diminished due to lock contentions which may frequently occur. To overcome this limitation, we propose a scheme of Urgent Queue Path, called UQP, which can significantly reduce the frequency of the lock contentions. Experimental results clearly show that the UQP outperforms 35.6% over the conventional Vanilla kernel.