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

Tom Talpey
2022-10-21T14:33:50Z

On 10/20/2022 4:42 PM, Long Li wrote:
>> [Bernard wrote...]

>>> + props->max_qp_wr = MAX_SEND_BUFFERS_PER_QUEUE;
>>> +
>>> + /*
>>> + * max_cqe could be potentially much bigger.
>>> + * As this version of driver only support RAW QP, set it to the same
>>> + * value as max_qp_wr
>>> + */
>>> + props->max_cqe = MAX_SEND_BUFFERS_PER_QUEUE;
>>> +
>>> + props->max_mr_size = MANA_IB_MAX_MR_SIZE;
>>> + props->max_mr = INT_MAX;
>>
>> How the 24 bit wide MR keys can handle INT_MAX unique
>> MR's?
>
> Not sure if I understand this correctly, lkey and rkey are u32 in ib_mr.

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.