Hi Max-
> On Mar 17, 2020, at 9:40 AM, Max Gurtovoy <maxg@xxxxxxxxxxxx> wrote:
>
> In some cases, e.g. when using ib_alloc_cq_any, one would like to know
> the completion vector that eventually assigned to the CQ. Cache this
> value during CQ creation.
I'm confused by the mention of the ib_alloc_cq_any() API here.
Is your design somehow dependent on the way the current ib_alloc_cq_any()
selects comp_vectors? The contract for _any() is that it is an API for
callers that simply do not care about what comp_vector is chosen. There's
no guarantee that the _any() comp_vector allocator will continue to use
round-robin in the future, for instance.
If you want to guarantee that there is an SRQ for each comp_vector and a
comp_vector for each SRQ, stick with a CQ allocation API that enables
explicit selection of the comp_vector value, and cache that value in the
caller, not in the core data structures.
> Signed-off-by: Max Gurtovoy <maxg@xxxxxxxxxxxx>
> ---
> drivers/infiniband/core/cq.c | 1 +
> include/rdma/ib_verbs.h | 1 +
> 2 files changed, 2 insertions(+)
>
> diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c
> index 4f25b24..a7cbf52 100644
> --- a/drivers/infiniband/core/cq.c
> +++ b/drivers/infiniband/core/cq.c
> @@ -217,6 +217,7 @@ struct ib_cq *__ib_alloc_cq_user(struct ib_device *dev, void *private,
> cq->device = dev;
> cq->cq_context = private;
> cq->poll_ctx = poll_ctx;
> + cq->comp_vector = comp_vector;
> atomic_set(&cq->usecnt, 0);
>
> cq->wc = kmalloc_array(IB_POLL_BATCH, sizeof(*cq->wc), GFP_KERNEL);
> diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h
> index fc8207d..0d61772 100644
> --- a/include/rdma/ib_verbs.h
> +++ b/include/rdma/ib_verbs.h
> @@ -1558,6 +1558,7 @@ struct ib_cq {
> struct ib_device *device;
> struct ib_ucq_object *uobject;
> ib_comp_handler comp_handler;
> + u32 comp_vector;
> void (*event_handler)(struct ib_event *, void *);
> void *cq_context;
> int cqe;
> --
> 1.8.3.1
>
--
Chuck Lever
chucklever@xxxxxxxxx
