Re: [PATCH v4 01/14] svcrdma: Reduce the number of rdma_rw contexts per-QP

Edward Srouji
2025-05-08T08:41:33Z

On 5/6/2025 5:22 PM, Jason Gunthorpe wrote:
> On Tue, May 06, 2025 at 10:19:06AM -0400, Chuck Lever wrote:
>>>> In this patch I'm trying to include the reg/inv multiplier in the
>>>> calculation, but that doesn't seem to be enough to make "accept"
>>>> reliable, IMO due to this extra calculation in calc_sq_size().
>>> Did ib_create_qp get called with more than max_qp_wr ?
>> The request was for, like, 9300 SQEs. max_qp_wr is 32K on my systems.
> Sounds like it is broken then..
>
> props->max_qp_wr = 1 << MLX5_CAP_GEN(mdev, log_max_qp_sz);
>
> So it is ignoring the wqe_size adustment.. It should adjust by the worst
> case result of calc_send_wqe() for the device..
How do you suggest adjusting to the worst case?
How inline messages could be addressed and taken into account?
Even if we ignore the inline size, worst case potentially could be less
than 1/8th of the max HCA CAP, not sure we want to deliver this as a
limitation to users.
> Jason
>