[SPDK] Re: About SPDK I/OAT Driver.

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Hi Jim,

Thanks for your reply.
Now, I am trying to use SPDK I/OAT driver to copy data.  =

Copy data between SSD's CMB and host memory. =

The CMB type can be configured as prefetchable or non-prefetchable by upgra=
de SSD firmware.

The test application use "spdk_ioat_submit_copy" to copy data , =

Host memory is allocated by spdk_dma_zmalloc(...), CMB is allocated by spdk=
_nvme_ctrlr_map_cmb(...).

Test result found that the prefetchable CMB performance is poorer than non-=
prefetchable CMB.
Could you give me advice why prefetchable CMB is poorer than non-prefetchab=
le=EF=BC=9F
Thanks a lot!

Test environment=EF=BC=9A

IOAT device info :
  Found matching device at 0000:80:04.7 vendor:0x8086 device:0x2021
attach ioat chan 0x171d010

CPU=EF=BC=9A
 Intel(R) Xeon(R) Gold 6230 CPU @ 2.10GHz

Motherboard : Supermicro X11DPU

SPDK git version : 307b8c112ffd90a26d53dd15fad67bd9038ef526
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