Programs intended for running on GPUs or other computing accelerators that support Remote DMA (RDMA), can use this library to enable direct disk access from the accelerators. Currently, the library supports setting up mappings for GPUDirect-capable Nvidia GPUs.

2019年8月6日 · The NVIDIA DGX-2, consisting of 16 V100 GPUs contains a stock configuration of 30 TB of NVMe SSD memory (8x 3.84TB) and 1.5 TB of system memory. Enablement of DMA operations from drives allows for fast memory access with increased bandwidth, lower latency, and potentially unlimited storage capacity.

2023年1月10日 · In this paper, we propose an efficient and dynamically adaptive user-level DMA (UDMA) mechanism for different I/O sizes for NVMe SSDs, which lightens the I/O software stack by amortizing per-request latency.

This ensures the DMA engine in the NVMe A SSD sends MemWr or MemRd TLPs to the CMB on the NVMe B SSD. Note work still needs to be done on allocator, VFIO and ACS issues. The P2PDMA framework proposed for the Linux Kernel is much more general than SPDK.

当Host的driver需要跟PCIe设备传输数据的时候，只需要告诉PCIe设备存放数据的地址就可以了，下面将介绍NVMe是如何使用DMA传输NVMe Command的。 先回顾下之前文章提到的内容，一是NVMe Command占用64个字节，二是NVMe的PCIe BAR空间被映射到虚拟内存空间（其中包括用来通知NVMe SSD Controller读取Command的Doorbell寄存器）。 另外，提一下NVMe数据 …

2019年5月28日 · The SATA controller (for example) has I/O registers that the CPU needs to write to, to program it to make a DMA transfer of n sectors from a certain disk offset to a certain physical memory address. Some or all of these I/O registers might be accessible via MMIO (normal loads and stores to special addresses) rather than in / out port IO.

2012年6月11日 · SWMA2, MWDMA2, and UDMA6 are DMA Mode settings. If your motherboard BIOS is AMIBIOS then the DMA Mode settings are for CD and DVD drives, not SSDs. SWDMA2 has a data transfer rate of 8.3MB/s....

We evaluate SPIN on NVIDIA and AMD GPUs us-ing standard file I/O benchmarks, application traces and end-to-end experiments. SPIN achieves significant per-formance speedups across a wide range of workloads, ex-ceeding P2P throughput by up to an order of magnitude.

I am trying to use DMA to transfer data from an SSD drive (PCIe device) to an AXI4 stream peripheral e.g., a FIFO implemented on FPGA. DDR memory is not involved in the transaction. PCIe is implemented using the AXI Memory Mapped to PCI Express (2.9) IP and configured as root complex in Vivado.

2022年2月23日 · UPM-DMA can amortize per-request latency by dynamically selecting the appropriate pinned memory mode for different sizes of IO requests. We integrate UPM-DMA into SPDK and do experiments based on SPDK’s official testing tools, and the experimental results verify the effectiveness of our work.