Spdk_nvme_ctrlr_process_admin_completions() Send the given admin command to the NVMe controller. Process any outstanding completions for I/O submitted on a queue pair. Submit a flush request to the specified NVMe namespace. Submit a data set management request to the specified NVMe namespace. Submit a write zeroes I/O to the specified NVMe namespace. Submit a write I/O to the specified NVMe namespace. Submit a read I/O to the specified NVMe namespace. Submits a read I/O to the specified NVMe namespace. Get a handle to a namespace for the given controller.
Perf -q 1 -o 4096 -w read -r 'trtype:PCIe traddr:0000:04:00.0' -t 200 -e 'PRACT=0,PRCKH=GUARD'Įnumerate the bus indicated by the transport ID and attach the userspace NVMe driver to each device found if desired.Īllocate an I/O queue pair (submission and completion queue).
The following examples demonstrate how to use perf.Įxample: Using perf for 4K 100% Random Read workload to a local NVMe SSD for 300 seconds The perf benchmarking tool provides several run time options to support the most common workload. fio with the 4K 100% Random Read workload. We have measured up to 2.6 times more IOPS/core when using perf vs.
Therefore, SPDK provides a perf benchmarking tool which has minimal overhead during benchmarking. However, that flexibility adds overhead and reduces the efficiency of SPDK. The fio tool is widely used because it is very flexible. NVMe perf utility in the examples/nvme/perf is one of the examples which also can be used for performance tests. See the fio start up guide for more details. SPDK provides a plugin to the very popular fio tool for running some basic benchmarks. They are all in the examples/nvme directory in the repository. There are a number of examples provided that demonstrate how to use the NVMe library. Users may now call spdk_nvme_probe() on both local PCI busses and on remote NVMe over Fabrics discovery services. More recently, the library has been improved to also connect to remote NVMe devices via NVMe over Fabrics. I/O is submitted asynchronously via queue pairs and the general flow isn't entirely dissimilar from Linux's libaio. The library controls NVMe devices by directly mapping the PCI BAR into the local process and performing MMIO. It is entirely passive, meaning that it spawns no threads and only performs actions in response to function calls from the application itself. The NVMe driver is a C library that may be linked directly into an application that provides direct, zero-copy data transfer to and from NVMe SSDs.