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

@ -252,6 +252,34 @@ struct ib_cq *__ib_alloc_cq_user(struct ib_device *dev, void *private,
}
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.

View File

@ -1767,8 +1767,8 @@ static int srpt_create_ch_ib(struct srpt_rdma_ch *ch)
goto out;
retry:
ch->cq = ib_alloc_cq(sdev->device, ch, ch->rq_size + sq_size,
0 /* XXX: spread CQs */, IB_POLL_WORKQUEUE);
ch->cq = ib_alloc_cq_any(sdev->device, ch, ch->rq_size + sq_size,
IB_POLL_WORKQUEUE);
if (IS_ERR(ch->cq)) {
ret = PTR_ERR(ch->cq);
pr_err("failed to create CQ cqe= %d ret= %d\n",

View File

@ -1654,15 +1654,17 @@ static struct smbd_connection *_smbd_get_connection(
info->send_cq = NULL;
info->recv_cq = NULL;
info->send_cq = ib_alloc_cq(info->id->device, info,
info->send_credit_target, 0, IB_POLL_SOFTIRQ);
info->send_cq =
ib_alloc_cq_any(info->id->device, info,
info->send_credit_target, IB_POLL_SOFTIRQ);
if (IS_ERR(info->send_cq)) {
info->send_cq = NULL;
goto alloc_cq_failed;
}
info->recv_cq = ib_alloc_cq(info->id->device, info,
info->receive_credit_max, 0, IB_POLL_SOFTIRQ);
info->recv_cq =
ib_alloc_cq_any(info->id->device, info,
info->receive_credit_max, IB_POLL_SOFTIRQ);
if (IS_ERR(info->recv_cq)) {
info->recv_cq = NULL;
goto alloc_cq_failed;

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

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@ -685,9 +685,9 @@ rdma_create_trans(struct p9_client *client, const char *addr, char *args)
goto error;
/* Create the Completion Queue */
rdma->cq = ib_alloc_cq(rdma->cm_id->device, client,
opts.sq_depth + opts.rq_depth + 1,
0, IB_POLL_SOFTIRQ);
rdma->cq = ib_alloc_cq_any(rdma->cm_id->device, client,
opts.sq_depth + opts.rq_depth + 1,
IB_POLL_SOFTIRQ);
if (IS_ERR(rdma->cq))
goto error;

View File

@ -454,14 +454,14 @@ static struct svc_xprt *svc_rdma_accept(struct svc_xprt *xprt)
dprintk("svcrdma: error creating PD for connect request\n");
goto errout;
}
newxprt->sc_sq_cq = ib_alloc_cq(dev, newxprt, newxprt->sc_sq_depth,
0, IB_POLL_WORKQUEUE);
newxprt->sc_sq_cq = ib_alloc_cq_any(dev, newxprt, newxprt->sc_sq_depth,
IB_POLL_WORKQUEUE);
if (IS_ERR(newxprt->sc_sq_cq)) {
dprintk("svcrdma: error creating SQ CQ for connect request\n");
goto errout;
}
newxprt->sc_rq_cq = ib_alloc_cq(dev, newxprt, rq_depth,
0, IB_POLL_WORKQUEUE);
newxprt->sc_rq_cq =
ib_alloc_cq_any(dev, newxprt, rq_depth, IB_POLL_WORKQUEUE);
if (IS_ERR(newxprt->sc_rq_cq)) {
dprintk("svcrdma: error creating RQ CQ for connect request\n");
goto errout;

View File

@ -521,18 +521,17 @@ int rpcrdma_ep_create(struct rpcrdma_xprt *r_xprt)
init_waitqueue_head(&ep->rep_connect_wait);
ep->rep_receive_count = 0;
sendcq = ib_alloc_cq(ia->ri_id->device, NULL,
ep->rep_attr.cap.max_send_wr + 1,
ia->ri_id->device->num_comp_vectors > 1 ? 1 : 0,
IB_POLL_WORKQUEUE);
sendcq = ib_alloc_cq_any(ia->ri_id->device, NULL,
ep->rep_attr.cap.max_send_wr + 1,
IB_POLL_WORKQUEUE);
if (IS_ERR(sendcq)) {
rc = PTR_ERR(sendcq);
goto out1;
}
recvcq = ib_alloc_cq(ia->ri_id->device, NULL,
ep->rep_attr.cap.max_recv_wr + 1,
0, IB_POLL_WORKQUEUE);
recvcq = ib_alloc_cq_any(ia->ri_id->device, NULL,
ep->rep_attr.cap.max_recv_wr + 1,
IB_POLL_WORKQUEUE);
if (IS_ERR(recvcq)) {
rc = PTR_ERR(recvcq);
goto out2;