Function: host_register_v2

Ascend 950PR/Ascend 950DT

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Atlas A3 training products/Atlas A3 inference products

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Atlas A2 training products/Atlas A2 inference products

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Atlas training products

x

Atlas inference products

x

Atlas 200I/500 A2 inference products

x

ptr

Host memory address.

The host memory address must be 4K-page-aligned.

If the OS kernel version is 5.10 or earlier, using non-page-locked memory will cause exceptions. Therefore, you must call aclrtMallocHost to allocate page-locked host memory.

If the OS kernel version is later than 5.10, non-page-locked host memory can be used. Therefore, you can either call aclrtMallocHost to allocate page-locked host memory or call malloc to allocate non-page-locked host memory.

size

Buffer size in bytes.

flag

Memory registration type.

• 0x2: ACL_HOST_REG_MAPPED: Maps and registers host memory as a memory address that can be accessed by the device, and then calls acl.rt.host_get_device_pointer to obtain the mapped device memory address.
• 0x4: ACL_HOST_REG_IOMEMORY: Maps and registers the I/O space (registers and cache) of a third-party PCIe device on the host as accessible to the device, including read and write operations. Reserved. Not supported yet.
• 0x8: ACL_HOST_REG_READONLY: Maps and registers host memory as read-only to the device. This reserved option is not supported currently.
• 0x10000000: ACL_HOST_REG_PINNED: Registers host non-page-locked memory as page-locked memory.

ret

Int, 0 on success; else failure.