On Tue, May 17, 2022 at 07:32:51PM +0000, Long Li wrote:

quoted

Subject: Re: [PATCH 05/12] net: mana: Set the DMA device max page size

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

quoted

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?

Yes, this is the maximum page size used in hardware page tables.

As I said, it should be the size of the sge in the WQE, not the
"hardware page tables"

Jason