RDS: IB: Add vector spreading for cqs

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 <santosh.shilimkar@oracle.com>

diff --git a/net/rds/ib.c b/net/rds/ib.c
index 5680d90b0b779ec41d019f1d0797dca7b5072ece..8d70884d7bb60294c1402892bff3ebe4c81d3663 100644 (file)
--- 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 c62e5513d306c38c2b058f5eba61fa2eaa582c45..1fe9f79fead52dd8cc00569d6955872ca86ad825 100644 (file)
--- a/net/rds/ib.h
+++ b/net/rds/ib.h
@@ -185,6 +185,10 @@ struct rds_ib_connection {
 
        /* Endpoint role in connection */
        bool                    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 4d1bf04b06b5b458ea16ec625396bc7443b9f414..33c8584ada1fdeddf66a312b8d41fbcb458daff2 100644 (file)
--- 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)