Commit 52f7aeb7 authored by Shuhei Matsumoto's avatar Shuhei Matsumoto Committed by Tomasz Zawadzki
Browse files

nvmf/rdma: Speed up qpair lookup by using RB tree 



To speed up qpair lookup, an idea to use the DPDK hash library was
proposed. But we have some concerns for the idea, we may see performance
regression for small configuration, lib/nvmf is depending on the DPDK
feature, and so on.

On the other hand, RB tree is simple to use and is not likely to have
negative side effect.

To use RB tree easily, cache QP num into struct spdk_nvmf_rdma_qpair.

Change-Id: Id4ea4e75692f86335b3e984c3fc128e187f22c72
Signed-off-by: default avatarShuhei Matsumoto <smatsumoto@nvidia.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/11798


Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Community-CI: Mellanox Build Bot
Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
parent 7613e3fe

lib/nvmf/rdma.c

+27 −17
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ 
#include "spdk/nvmf_transport.h"

#include "spdk/string.h"

#include "spdk/trace.h"

#include "spdk/tree.h"

#include "spdk/util.h"



#include "spdk_internal/assert.h"
@@ -327,6 +328,9 @@ struct spdk_nvmf_rdma_qpair { 
	struct spdk_rdma_srq			*srq;

	struct rdma_cm_id			*listen_id;



	/* Cache the QP number to improve QP search by RB tree. */

	uint32_t				qp_num;



	/* The maximum number of I/O outstanding on this connection at one time */

	uint16_t				max_queue_depth;
@@ -364,7 +368,7 @@ struct spdk_nvmf_rdma_qpair { 
	/* Number of requests not in the free state */

	uint32_t				qd;



	TAILQ_ENTRY(spdk_nvmf_rdma_qpair)	link;

	RB_ENTRY(spdk_nvmf_rdma_qpair)		node;



	STAILQ_ENTRY(spdk_nvmf_rdma_qpair)	recv_link;
@@ -419,7 +423,7 @@ struct spdk_nvmf_rdma_poller { 
	struct spdk_nvmf_rdma_resources		*resources;

	struct spdk_nvmf_rdma_poller_stat	stat;



	TAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs;

	RB_HEAD(qpairs_tree, spdk_nvmf_rdma_qpair) qpairs;



	STAILQ_HEAD(, spdk_nvmf_rdma_qpair)	qpairs_pending_recv;
@@ -517,6 +521,14 @@ static const struct spdk_json_object_decoder rdma_transport_opts_decoder[] = { 
	},

};



static int

nvmf_rdma_qpair_compare(struct spdk_nvmf_rdma_qpair *rqpair1, struct spdk_nvmf_rdma_qpair *rqpair2)

{

	return rqpair1->qp_num - rqpair2->qp_num;

}



RB_GENERATE_STATIC(qpairs_tree, spdk_nvmf_rdma_qpair, node, nvmf_rdma_qpair_compare);



static bool

nvmf_rdma_request_process(struct spdk_nvmf_rdma_transport *rtransport,

			  struct spdk_nvmf_rdma_request *rdma_req);
@@ -893,7 +905,7 @@ nvmf_rdma_qpair_destroy(struct spdk_nvmf_rdma_qpair *rqpair) 
	}



	if (rqpair->poller) {

		TAILQ_REMOVE(&rqpair->poller->qpairs, rqpair, link);

		RB_REMOVE(qpairs_tree, &rqpair->poller->qpairs, rqpair);



		if (rqpair->srq != NULL && rqpair->resources != NULL) {

			/* Drop all received but unprocessed commands for this queue and return them to SRQ */
@@ -1017,6 +1029,8 @@ nvmf_rdma_qpair_initialize(struct spdk_nvmf_qpair *qpair) 
		goto error;

	}



	rqpair->qp_num = rqpair->rdma_qp->qp->qp_num;



	rqpair->max_send_depth = spdk_min((uint32_t)(rqpair->max_queue_depth * 2),

					  qp_init_attr.cap.max_send_wr);

	rqpair->max_send_sge = spdk_min(NVMF_DEFAULT_TX_SGE, qp_init_attr.cap.max_send_sge);
@@ -1205,7 +1219,7 @@ nvmf_rdma_event_accept(struct rdma_cm_id *id, struct spdk_nvmf_rdma_qpair *rqpai 
	 * Fields below are ignored by rdma cm if qpair has been

	 * created using rdma cm API. */

	ctrlr_event_data.srq = rqpair->srq ? 1 : 0;

	ctrlr_event_data.qp_num = rqpair->rdma_qp->qp->qp_num;

	ctrlr_event_data.qp_num = rqpair->qp_num;



	rc = spdk_rdma_qp_accept(rqpair->rdma_qp, &ctrlr_event_data);

	if (rc) {
@@ -2847,7 +2861,7 @@ nvmf_rdma_disconnect_qpairs_on_port(struct spdk_nvmf_rdma_transport *rtransport, 


	TAILQ_FOREACH(rgroup, &rtransport->poll_groups, link) {

		TAILQ_FOREACH(rpoller, &rgroup->pollers, link) {

			TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {

			RB_FOREACH(rqpair, qpairs_tree, &rpoller->qpairs) {

				if (rqpair->listen_id == port->id) {

					spdk_nvmf_qpair_disconnect(&rqpair->qpair, NULL, NULL);

				}
@@ -3275,7 +3289,7 @@ nvmf_rdma_poll_group_create(struct spdk_nvmf_transport *transport, 
		poller->device = device;

		poller->group = rgroup;



		TAILQ_INIT(&poller->qpairs);

		RB_INIT(&poller->qpairs);

		STAILQ_INIT(&poller->qpairs_pending_send);

		STAILQ_INIT(&poller->qpairs_pending_recv);
@@ -3401,7 +3415,7 @@ nvmf_rdma_poll_group_destroy(struct spdk_nvmf_transport_poll_group *group) 
	TAILQ_FOREACH_SAFE(poller, &rgroup->pollers, link, tmp) {

		TAILQ_REMOVE(&rgroup->pollers, poller, link);



		TAILQ_FOREACH_SAFE(qpair, &poller->qpairs, link, tmp_qpair) {

		RB_FOREACH_SAFE(qpair, qpairs_tree, &poller->qpairs, tmp_qpair) {

			nvmf_rdma_qpair_destroy(qpair);

		}
@@ -3491,7 +3505,7 @@ nvmf_rdma_poll_group_add(struct spdk_nvmf_transport_poll_group *group, 
		return -1;

	}



	TAILQ_INSERT_TAIL(&poller->qpairs, rqpair, link);

	RB_INSERT(qpairs_tree, &poller->qpairs, rqpair);



	rc = nvmf_rdma_event_accept(rqpair->cm_id, rqpair);

	if (rc) {
@@ -3614,15 +3628,11 @@ nvmf_rdma_close_qpair(struct spdk_nvmf_qpair *qpair, 
static struct spdk_nvmf_rdma_qpair *

get_rdma_qpair_from_wc(struct spdk_nvmf_rdma_poller *rpoller, struct ibv_wc *wc)

{

	struct spdk_nvmf_rdma_qpair *rqpair;

	/* @todo: improve QP search */

	TAILQ_FOREACH(rqpair, &rpoller->qpairs, link) {

		if (wc->qp_num == rqpair->rdma_qp->qp->qp_num) {

			return rqpair;

		}

	}

	SPDK_ERRLOG("Didn't find QP with qp_num %u\n", wc->qp_num);

	return NULL;

	struct spdk_nvmf_rdma_qpair find;



	find.qp_num = wc->qp_num;



	return RB_FIND(qpairs_tree, &rpoller->qpairs, &find);

}



#ifdef DEBUG