IO内存是直接把寄存器的地址空间直接映射到系统地址空间,系统地址空间往往会保留一段内存区用于这种MMIO的映射(当然肯定是位于系统内存区),这样系统可以直接使用普通的访存指令直接访问设备的寄存器,随着计算机内存容量的日益增大,这种方式更是显出独特的优势,在性能至上的理念下,使用MMIO可以最大限度满足日益增长的系统和...
it's easiest if you write the functions from bottom to top. By that we mean if functionfooperforms some asynchronous operation and when that completes functionbaris called, then functionbarperforms some operation that calls functionbazon completion, a good way to write it is as such: ...
This can result in significantly fewer MMIO writes to the doorbell register under heavy load, greatly improving performance. spdk_nvme_ctrlr_get_regs_cmbsz() was added to report the size of the controller memory buffer, if available.
针对执行失败的请求,QP并不会将其丢弃,而是先加入queued_req队列,以便后续做retry处理,当queued_req不为空的时候,后续新的请求都会提交到该队列,以保证之前失败的请求先做执行。 最后,每个QP还会绑定两个doorbell寄存器(每个doorbell占用4字节空间),以便向设备控制通知cmd的就绪情况,以及cpl的完成情况(基于MMIO方式更新...
#include "spdk/mmio.h" #include "spdk/pci_ids.h" #include "spdk/util.h" #include "spdk/memory.h" #include "spdk/nvme_intel.h" #include "spdk/nvmf_spec.h" #include "spdk/tree.h" #include "spdk/uuid.h" #include "spdk_internal/assert.h" #include "spdk/log.h" ...
用户空间驱动程序利用 uio 或 vfio 中的功能将设备的 PCI BAR 映射到当前进程,从而允许驱动程序直接执行 MMIO。例如,SPDK NVMe 驱动程序映射 NVMe 设备的 BAR,然后按照 NVMe 规范...
Provides direct, zero-copy data transfer to and from NVMe SSDs. It controls NVMe devices by directly mapping the PCI BAR into the local process and performing MMIO. I/O is submitted asynchronously via queue pairs. NVMe over Fabrics Target ...
mmio.h TEST_HEADER include/spdk/bdev_module.h TEST_HEADER include/spdk/opal.h TEST_HEADER include/spdk/event.h TEST_HEADER include/spdk/base64.h TEST_HEADER include/spdk/nvmf.h TEST_HEADER include/spdk/nvmf_spec.h TEST_HEADER include/spdk/blobfs_bdev.h TEST_HEADER include/spdk/fd.h TEST...
This can result in significantly fewer MMIO writes to the doorbell register under heavy load, greatly improving performance. spdk_nvme_ctrlr_get_regs_cmbsz() was added to report the size of the controller memory buffer, if available. spdk_nvme_ctrlr_get_flags() was added to return ...
最后,每个QP还会绑定两个doorbell寄存器(每个doorbell占用4字节空间),以便向设备控制通知cmd的就绪情况,以及cpl的完成情况(基于MMIO方式更新) IO处理 创建IO qpair 根据NVMe协议要求:先创建IO CQ再创建IO SQ,如下图所示 image-20230314141340176.png SPDK使用polling机制来检查CQ,而不是使用MSI/MSI-X等中断形式,在创建...