Thread (27 messages) flat view 27 messages, 2 authors, 2016-12-07

[net-next][PATCH v2 12/18] RDS: IB: Add vector spreading for cqs

From: Santosh Shilimkar <hidden>
Date: 2016-12-07 04:03:57
Also in: lkml
Subsystem: networking [general], rds - reliable datagram sockets, the rest · Maintainers: "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Allison Henderson, Linus Torvalds

Based on available device vectors, allocate cqs accordingly to
get better spread of completion vectors which helps performace
great deal..

Signed-off-by: Santosh Shilimkar <redacted>
---
 net/rds/ib.c    | 11 +++++++++++
 net/rds/ib.h    |  5 +++++
 net/rds/ib_cm.c | 40 +++++++++++++++++++++++++++++++++++++---
 3 files changed, 53 insertions(+), 3 deletions(-)
diff --git a/net/rds/ib.c b/net/rds/ib.c
index 5680d90..8d70884 100644
--- a/net/rds/ib.c
+++ b/net/rds/ib.c
@@ -111,6 +111,9 @@ static void rds_ib_dev_free(struct work_struct *work)
 		kfree(i_ipaddr);
 	}
 
+	if (rds_ibdev->vector_load)
+		kfree(rds_ibdev->vector_load);
+
 	kfree(rds_ibdev);
 }
 
@@ -159,6 +162,14 @@ static void rds_ib_add_one(struct ib_device *device)
 	rds_ibdev->max_initiator_depth = device->attrs.max_qp_init_rd_atom;
 	rds_ibdev->max_responder_resources = device->attrs.max_qp_rd_atom;
 
+	rds_ibdev->vector_load = kzalloc(sizeof(int) * device->num_comp_vectors,
+					 GFP_KERNEL);
+	if (!rds_ibdev->vector_load) {
+		pr_err("RDS/IB: %s failed to allocate vector memory\n",
+			__func__);
+		goto put_dev;
+	}
+
 	rds_ibdev->dev = device;
 	rds_ibdev->pd = ib_alloc_pd(device, 0);
 	if (IS_ERR(rds_ibdev->pd)) {
diff --git a/net/rds/ib.h b/net/rds/ib.h
index 4987387..4b133b8 100644
--- a/net/rds/ib.h
+++ b/net/rds/ib.h
@@ -185,6 +185,10 @@ struct rds_ib_connection {
 
 	/* Endpoint role in connection */
 	int			i_active_side;
+
+	/* Send/Recv vectors */
+	int			i_scq_vector;
+	int			i_rcq_vector;
 };
 
 /* This assumes that atomic_t is at least 32 bits */
@@ -227,6 +231,7 @@ struct rds_ib_device {
 	spinlock_t		spinlock;	/* protect the above */
 	atomic_t		refcount;
 	struct work_struct	free_work;
+	int			*vector_load;
 };
 
 #define ibdev_to_node(ibdev) dev_to_node(ibdev->dma_device)
diff --git a/net/rds/ib_cm.c b/net/rds/ib_cm.c
index 4d1bf04..33c8584 100644
--- a/net/rds/ib_cm.c
+++ b/net/rds/ib_cm.c
@@ -358,6 +358,28 @@ static void rds_ib_cq_comp_handler_send(struct ib_cq *cq, void *context)
 	tasklet_schedule(&ic->i_send_tasklet);
 }
 
+static inline int ibdev_get_unused_vector(struct rds_ib_device *rds_ibdev)
+{
+	int min = rds_ibdev->vector_load[rds_ibdev->dev->num_comp_vectors - 1];
+	int index = rds_ibdev->dev->num_comp_vectors - 1;
+	int i;
+
+	for (i = rds_ibdev->dev->num_comp_vectors - 1; i >= 0; i--) {
+		if (rds_ibdev->vector_load[i] < min) {
+			index = i;
+			min = rds_ibdev->vector_load[i];
+		}
+	}
+
+	rds_ibdev->vector_load[index]++;
+	return index;
+}
+
+static inline void ibdev_put_vector(struct rds_ib_device *rds_ibdev, int index)
+{
+	rds_ibdev->vector_load[index]--;
+}
+
 /*
  * This needs to be very careful to not leave IS_ERR pointers around for
  * cleanup to trip over.
@@ -399,25 +421,30 @@ static int rds_ib_setup_qp(struct rds_connection *conn)
 	/* Protection domain and memory range */
 	ic->i_pd = rds_ibdev->pd;
 
+	ic->i_scq_vector = ibdev_get_unused_vector(rds_ibdev);
 	cq_attr.cqe = ic->i_send_ring.w_nr + fr_queue_space + 1;
-
+	cq_attr.comp_vector = ic->i_scq_vector;
 	ic->i_send_cq = ib_create_cq(dev, rds_ib_cq_comp_handler_send,
 				     rds_ib_cq_event_handler, conn,
 				     &cq_attr);
 	if (IS_ERR(ic->i_send_cq)) {
 		ret = PTR_ERR(ic->i_send_cq);
 		ic->i_send_cq = NULL;
+		ibdev_put_vector(rds_ibdev, ic->i_scq_vector);
 		rdsdebug("ib_create_cq send failed: %d\n", ret);
 		goto out;
 	}
 
+	ic->i_rcq_vector = ibdev_get_unused_vector(rds_ibdev);
 	cq_attr.cqe = ic->i_recv_ring.w_nr;
+	cq_attr.comp_vector = ic->i_rcq_vector;
 	ic->i_recv_cq = ib_create_cq(dev, rds_ib_cq_comp_handler_recv,
 				     rds_ib_cq_event_handler, conn,
 				     &cq_attr);
 	if (IS_ERR(ic->i_recv_cq)) {
 		ret = PTR_ERR(ic->i_recv_cq);
 		ic->i_recv_cq = NULL;
+		ibdev_put_vector(rds_ibdev, ic->i_rcq_vector);
 		rdsdebug("ib_create_cq recv failed: %d\n", ret);
 		goto out;
 	}
@@ -780,10 +807,17 @@ void rds_ib_conn_path_shutdown(struct rds_conn_path *cp)
 		/* first destroy the ib state that generates callbacks */
 		if (ic->i_cm_id->qp)
 			rdma_destroy_qp(ic->i_cm_id);
-		if (ic->i_send_cq)
+		if (ic->i_send_cq) {
+			if (ic->rds_ibdev)
+				ibdev_put_vector(ic->rds_ibdev, ic->i_scq_vector);
 			ib_destroy_cq(ic->i_send_cq);
-		if (ic->i_recv_cq)
+		}
+
+		if (ic->i_recv_cq) {
+			if (ic->rds_ibdev)
+				ibdev_put_vector(ic->rds_ibdev, ic->i_rcq_vector);
 			ib_destroy_cq(ic->i_recv_cq);
+		}
 
 		/* then free the resources that ib callbacks use */
 		if (ic->i_send_hdrs)
-- 
1.9.1
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