在 2024/9/8 14:18, Michael Guralnik 写道:
On 06/09/2024 08:35, Zhu Yanjun wrote:
As such, it seems that it can save memory via not pinning down the
underlying physical pages of the address space, and track the validity
of the mappings.
What is the difference on the performance with/without ODP enabled? And
about memory usage, is there any test result about this?
And ODP can be used mlx5 IB device? Or ODP can only be used in mlx5
RoCEv2 device?
The performance while using ODP is highly dependent on many factors that
dictate how many page faults the kernel will have to deal with.
Each page fault will introduce a latency hit.
Both the examples in rdma_core (e.g ibv_rc_pingpong) and the perftest
(e.g. ib_write_bw) support running with ODP to test this.
Thanks a lot. I have developed ODP for other RDMA devices. From my
tests, it seems that with ODP, the system memory is needed less than
without ODP.
From your descriptions, it seems that the latency of RDMA will increase
if I get you correctly.
If others (for example, bandwidth) remain unchanged, the tradeoff should
be between memory and latency.
Best Regards,
Zhu Yanjun
ODP can be used in both IB and RoCE.
Michael
Thanks,
Zhu Yanjun
