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>
This commit is contained in:
Chuck Lever
2019-07-29 13:22:09 -04:00
committed by Doug Ledford
parent 31d0e6c149
commit 20cf4e0267
7 changed files with 68 additions and 20 deletions

View File

@@ -3711,6 +3711,25 @@ static inline struct ib_cq *ib_alloc_cq(struct ib_device *dev, void *private,
NULL);
}
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);
/**
* ib_alloc_cq_any: Allocate kernel CQ
* @dev: The IB device
* @private: Private data attached to the CQE
* @nr_cqe: Number of CQEs in the CQ
* @poll_ctx: Context used for polling the CQ
*/
static inline struct ib_cq *ib_alloc_cq_any(struct ib_device *dev,
void *private, int nr_cqe,
enum ib_poll_context poll_ctx)
{
return __ib_alloc_cq_any(dev, private, nr_cqe, poll_ctx,
KBUILD_MODNAME);
}
/**
* ib_free_cq_user - Free kernel/user CQ
* @cq: The CQ to free