Lines Matching refs:a

21 done at a much more granular level than a full page.
37 memory to be describable by what is called a *PRP list*. To be described by a
41 * The first device page can be a partial page starting at any 4-byte aligned
44 * If there is more than one device page, the first device page must end on a
46 * The last device page begins on a physical 4KiB page boundary, but is not
47   required to end on a physical 4KiB page boundary.
55 User space drivers run in the context of a regular process and so have access
60 within a process. This file contains the virtual address to physical address
64 into whether a PCI device is directly transferring data to a set of physical
66 movement. When an operating system flags a page such that the virtual to
72 operating system also moves pages during a process called compaction, which
76 which may trigger a physical address rebalance to optimize interleaving.
78 POSIX provides the `mlock` call that forces a virtual page of memory to always
79 be backed by a physical page. In effect, this is disabling swapping. This does
81 static. The `mlock` call should not be confused with a **pin** call, and it
89 could change in future versions, but it is true today and has been for a number
90 of years (see the later section on the IOMMU for a future-proof solution).
100 Management Unit (IOMMU). An IOMMU is much like a regular MMU, except it
103 system, so the IOMMU associates a particular device with one of these mappings
107 address to a virtual address and then the virtual address to the physical
110 provides a device driver, `vfio-pci`, that allows a user to configure the IOMMU
113 This is a future-proof, hardware-accelerated solution for performing DMA
114 operations into and out of a user space process and forms the long-term