On Tue, May 17, 2022 at 02:04:29AM -0700, longli@linuxonhyperv.com wrote:

From: Long Li <longli@microsoft.com>

The system chooses default 64K page size if the device does not specify
the max page size the device can handle for DMA. This do not work well
when device is registering large chunk of memory in that a large page size
is more efficient.

Set it to the maximum hardware supported page size.

For RDMA devices this should be set to the largest segment size an
ib_sge can take in when posting work. It should not be the page size
of MR. 2M is a weird number for that, are you sure it is right?

Jason