Re: [PATCH rdma-next] RDMA/rdmavt: Decouple QP and SGE lists allocations

From: Dennis Dalessandro
Date: Tue May 11 2021 - 08:26:55 EST

On 5/11/21 6:36 AM, Leon Romanovsky wrote:
From: Leon Romanovsky <leonro@xxxxxxxxxx>

The rdmavt QP has fields that are both needed for the control and data
path. Such mixed declaration caused to the very specific allocation flow
with kzalloc_node and SGE list embedded into the struct rvt_qp.

This patch separates QP creation to two: regular memory allocation for
the control path and specific code for the SGE list, while the access to
the later is performed through derefenced pointer.

Such pointer and its context are expected to be in the cache, so
performance difference is expected to be negligible, if any exists.

Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>

This change is needed to convert QP to core allocation scheme. In that
scheme QP is allocated outside of the driver and size of such allocation
is constant and can be calculated at the compile time.

Thanks Leon, we'll get this put through our testing.