Commit cb97b377 authored by Kalesh AP's avatar Kalesh AP Committed by Leon Romanovsky
Browse files

RDMA/bnxt_re: Refurbish CQ to NQ hash calculation 



There are few use cases where CQ create and destroy
is seen before re-creating the CQ, this kind of use
case is disturbing the RR distribution and all the
active CQ getting mapped to only 2 NQ alternatively.

Fixing the CQ to NQ hash calculation by implementing
a quick load sorting mechanism under a mutex.

Using this, if the CQ was allocated and destroyed
before using it, the nq selecting algorithm still
obtains the least loaded CQ. Thus balancing the load
on NQs.

Signed-off-by: default avatarSelvin Xavier <selvin.xavier@broadcom.com>
Signed-off-by: default avatarKalesh AP <kalesh-anakkur.purayil@broadcom.com>
Link: https://patch.msgid.link/1731577748-1804-4-git-send-email-selvin.xavier@broadcom.com


Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
parent 30b87133

drivers/infiniband/hw/bnxt_re/bnxt_re.h

+2 −0
Original line number Diff line number Diff line
@@ -159,6 +159,8 @@ struct bnxt_re_pacing { 
struct bnxt_re_nq_record {

	struct bnxt_qplib_nq	nq[BNXT_RE_MAX_MSIX];

	int			num_msix;

	/* serialize NQ access */

	struct mutex		load_lock;

};



#define MAX_CQ_HASH_BITS		(16)

drivers/infiniband/hw/bnxt_re/ib_verbs.c

+26 −11
Original line number Diff line number Diff line
@@ -3029,6 +3029,28 @@ int bnxt_re_post_recv(struct ib_qp *ib_qp, const struct ib_recv_wr *wr, 
	return rc;

}



static struct bnxt_qplib_nq *bnxt_re_get_nq(struct bnxt_re_dev *rdev)

{

	int min, indx;



	mutex_lock(&rdev->nqr->load_lock);

	for (indx = 0, min = 0; indx < (rdev->nqr->num_msix - 1); indx++) {

		if (rdev->nqr->nq[min].load > rdev->nqr->nq[indx].load)

			min = indx;

	}

	rdev->nqr->nq[min].load++;

	mutex_unlock(&rdev->nqr->load_lock);



	return &rdev->nqr->nq[min];

}



static void bnxt_re_put_nq(struct bnxt_re_dev *rdev, struct bnxt_qplib_nq *nq)

{

	mutex_lock(&rdev->nqr->load_lock);

	nq->load--;

	mutex_unlock(&rdev->nqr->load_lock);

}



/* Completion Queues */

int bnxt_re_destroy_cq(struct ib_cq *ib_cq, struct ib_udata *udata)

{
@@ -3047,6 +3069,8 @@ int bnxt_re_destroy_cq(struct ib_cq *ib_cq, struct ib_udata *udata) 
		hash_del(&cq->hash_entry);

	}

	bnxt_qplib_destroy_cq(&rdev->qplib_res, &cq->qplib_cq);



	bnxt_re_put_nq(rdev, nq);

	ib_umem_release(cq->umem);



	atomic_dec(&rdev->stats.res.cq_count);
@@ -3065,8 +3089,6 @@ int bnxt_re_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr, 
		rdma_udata_to_drv_context(udata, struct bnxt_re_ucontext, ib_uctx);

	struct bnxt_qplib_dev_attr *dev_attr = &rdev->dev_attr;

	struct bnxt_qplib_chip_ctx *cctx;

	struct bnxt_qplib_nq *nq = NULL;

	unsigned int nq_alloc_cnt;

	int cqe = attr->cqe;

	int rc, entries;

	u32 active_cqs;
@@ -3117,16 +3139,10 @@ int bnxt_re_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr, 


		cq->qplib_cq.dpi = &rdev->dpi_privileged;

	}

	/*

	 * Allocating the NQ in a round robin fashion. nq_alloc_cnt is a

	 * used for getting the NQ index.

	 */

	nq_alloc_cnt = atomic_inc_return(&rdev->nq_alloc_cnt);

	nq = &rdev->nqr->nq[nq_alloc_cnt % (rdev->nqr->num_msix - 1)];

	cq->qplib_cq.max_wqe = entries;

	cq->qplib_cq.cnq_hw_ring_id = nq->ring_id;

	cq->qplib_cq.nq	= nq;

	cq->qplib_cq.coalescing = &rdev->cq_coalescing;

	cq->qplib_cq.nq = bnxt_re_get_nq(rdev);

	cq->qplib_cq.cnq_hw_ring_id = cq->qplib_cq.nq->ring_id;



	rc = bnxt_qplib_create_cq(&rdev->qplib_res, &cq->qplib_cq);

	if (rc) {
@@ -3136,7 +3152,6 @@ int bnxt_re_create_cq(struct ib_cq *ibcq, const struct ib_cq_init_attr *attr, 


	cq->ib_cq.cqe = entries;

	cq->cq_period = cq->qplib_cq.period;

	nq->budget++;



	active_cqs = atomic_inc_return(&rdev->stats.res.cq_count);

	if (active_cqs > rdev->stats.res.cq_watermark)

drivers/infiniband/hw/bnxt_re/main.c

+2 −0
Original line number Diff line number Diff line
@@ -1566,6 +1566,8 @@ static int bnxt_re_init_res(struct bnxt_re_dev *rdev) 


	bnxt_qplib_init_res(&rdev->qplib_res);



	mutex_init(&rdev->nqr->load_lock);



	for (i = 1; i < rdev->nqr->num_msix ; i++) {

		db_offt = rdev->en_dev->msix_entries[i].db_offset;

		rc = bnxt_qplib_enable_nq(rdev->en_dev->pdev, &rdev->nqr->nq[i - 1],

drivers/infiniband/hw/bnxt_re/qplib_fp.c

+1 −0
Original line number Diff line number Diff line
@@ -551,6 +551,7 @@ int bnxt_qplib_enable_nq(struct pci_dev *pdev, struct bnxt_qplib_nq *nq, 
	nq->pdev = pdev;

	nq->cqn_handler = cqn_handler;

	nq->srqn_handler = srqn_handler;

	nq->load = 0;



	/* Have a task to schedule CQ notifiers in post send case */

	nq->cqn_wq  = create_singlethread_workqueue("bnxt_qplib_nq");

drivers/infiniband/hw/bnxt_re/qplib_fp.h

+1 −0
Original line number Diff line number Diff line
@@ -519,6 +519,7 @@ struct bnxt_qplib_nq { 
	struct tasklet_struct		nq_tasklet;

	bool				requested;

	int				budget;

	u32				load;



	cqn_handler_t			cqn_handler;

	srqn_handler_t			srqn_handler;