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

From: Leon Romanovsky
Date: Tue May 11 2021 - 08:35:24 EST


On Tue, May 11, 2021 at 08:26:43AM -0400, Dennis Dalessandro wrote:
> 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>
> > ---
> > Hi,
> >
> > 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.

Thanks a lot.

>
> -Denny