Re: [Patch v8 12/12] RDMA/mana_ib: Add a driver for Microsoft Azure Network Adapter

From: Tom Talpey
Date: Fri Oct 21 2022 - 20:35:05 EST


On 10/21/2022 6:55 PM, Long Li wrote:
The upper 8 bits of an ib_mr remote token are reserved for use as a
rotating key, this allows a consumer to more safely reuse an ib_mr
without having to overallocate large region pools.

Tom.

Right, my point was that one cannot encode INT_MAX different MR
identifiers into 32 - 8 = 24 bits.

Best,
Bernard.

The hardware exposes the number of MRs that exceeds UINT32_MAX.
There is no software stack limit from hardware perspective.

In this case, maybe it's a good idea to set it to 0xFFFFFF. I'm making the change.

Actually, 2^24 MRs is enormous in itself. Does this driver
actually support that many? Without falling over?

Tom.