diff options
| author | Chuck Lever <chuck.lever@oracle.com> | 2019-07-29 13:22:09 -0400 |
|---|---|---|
| committer | Doug Ledford <dledford@redhat.com> | 2019-08-05 11:50:32 -0400 |
| commit | 20cf4e026730104892fa1268de0371a631cee294 (patch) | |
| tree | 08a7e60c303ff468d50a33d52e2bc98eab9b1b30 /drivers/infiniband/core/cq.c | |
| parent | 31d0e6c149b8c9a9bddc6d68f8600918bb771cb9 (diff) | |
rdma: Enable ib_alloc_cq to spread work over a device's comp_vectors
Send and Receive completion is handled on a single CPU selected at
the time each Completion Queue is allocated. Typically this is when
an initiator instantiates an RDMA transport, or when a target
accepts an RDMA connection.
Some ULPs cannot open a connection per CPU to spread completion
workload across available CPUs and MSI vectors. For such ULPs,
provide an API that allows the RDMA core to select a completion
vector based on the device's complement of available comp_vecs.
ULPs that invoke ib_alloc_cq() with only comp_vector 0 are converted
to use the new API so that their completion workloads interfere less
with each other.
Suggested-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Cc: <linux-cifs@vger.kernel.org>
Cc: <v9fs-developer@lists.sourceforge.net>
Link: https://lore.kernel.org/r/20190729171923.13428.52555.stgit@manet.1015granger.net
Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband/core/cq.c')
| -rw-r--r-- | drivers/infiniband/core/cq.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/drivers/infiniband/core/cq.c b/drivers/infiniband/core/cq.c index 7c599878ccf7..bbfded6d5d3d 100644 --- a/drivers/infiniband/core/cq.c +++ b/drivers/infiniband/core/cq.c @@ -253,6 +253,34 @@ out_free_cq: EXPORT_SYMBOL(__ib_alloc_cq_user); /** + * __ib_alloc_cq_any - allocate a completion queue + * @dev: device to allocate the CQ for + * @private: driver private data, accessible from cq->cq_context + * @nr_cqe: number of CQEs to allocate + * @poll_ctx: context to poll the CQ from + * @caller: module owner name + * + * Attempt to spread ULP Completion Queues over each device's interrupt + * vectors. A simple best-effort mechanism is used. + */ +struct ib_cq *__ib_alloc_cq_any(struct ib_device *dev, void *private, + int nr_cqe, enum ib_poll_context poll_ctx, + const char *caller) +{ + static atomic_t counter; + int comp_vector = 0; + + if (dev->num_comp_vectors > 1) + comp_vector = + atomic_inc_return(&counter) % + min_t(int, dev->num_comp_vectors, num_online_cpus()); + + return __ib_alloc_cq_user(dev, private, nr_cqe, comp_vector, poll_ctx, + caller, NULL); +} +EXPORT_SYMBOL(__ib_alloc_cq_any); + +/** * ib_free_cq_user - free a completion queue * @cq: completion queue to free. * @udata: User data or NULL for kernel object |