[PATCH 07/20] IB/mad: Convert ib_mad_private allocations from kmem_cache to kmalloc

[ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org]

From: Ira Weiny <ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

Use the new mad_size specified by devices for the allocations and DMA maps.

kmalloc is more flexible to support devices with different sized MADs and
research and testing showed that the current use of kmem_cache does not provide
performance benefits over kmalloc.

Signed-off-by: Ira Weiny <ira.weiny-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/infiniband/core/mad.c |   73 +++++++++++++++++------------------------
 1 files changed, 30 insertions(+), 43 deletions(-)

diff --git a/drivers/infiniband/core/mad.c b/drivers/infiniband/core/mad.c
index 031ae6f..b1ec225 100644
--- a/drivers/infiniband/core/mad.c
+++ b/drivers/infiniband/core/mad.c
@@ -59,8 +59,6 @@ MODULE_PARM_DESC(send_queue_size, "Size of send queue in number of work requests
 module_param_named(recv_queue_size, mad_recvq_size, int, 0444);
 MODULE_PARM_DESC(recv_queue_size, "Size of receive queue in number of work requests");
 
-static struct kmem_cache *ib_mad_cache;
-
 static struct list_head ib_mad_port_list;
 static u32 ib_mad_client_id = 0;
 
@@ -717,6 +715,13 @@ static void build_smp_wc(struct ib_qp *qp,
 	wc->port_num = port_num;
 }
 
+static struct ib_mad_private *alloc_mad_priv(struct ib_device *dev)
+{
+	return (kmalloc(sizeof(struct ib_mad_private_header) +
+			sizeof(struct ib_grh) +
+			dev->attributes.mad_size, GFP_ATOMIC));
+}
+
 /*
  * Return 0 if SMP is to be sent
  * Return 1 if SMP was consumed locally (whether or not solicited)
@@ -771,7 +776,8 @@ static int handle_outgoing_dr_smp(struct ib_mad_agent_private *mad_agent_priv,
 	}
 	local->mad_priv = NULL;
 	local->recv_mad_agent = NULL;
-	mad_priv = kmem_cache_alloc(ib_mad_cache, GFP_ATOMIC);
+
+	mad_priv = alloc_mad_priv(mad_agent_priv->agent.device);
 	if (!mad_priv) {
 		ret = -ENOMEM;
 		dev_err(&device->dev, "No memory for local response MAD\n");
@@ -801,10 +807,10 @@ static int handle_outgoing_dr_smp(struct ib_mad_agent_private *mad_agent_priv,
 			 */
 			atomic_inc(&mad_agent_priv->refcount);
 		} else
-			kmem_cache_free(ib_mad_cache, mad_priv);
+			kfree(mad_priv);
 		break;
 	case IB_MAD_RESULT_SUCCESS | IB_MAD_RESULT_CONSUMED:
-		kmem_cache_free(ib_mad_cache, mad_priv);
+		kfree(mad_priv);
 		break;
 	case IB_MAD_RESULT_SUCCESS:
 		/* Treat like an incoming receive MAD */
@@ -820,14 +826,14 @@ static int handle_outgoing_dr_smp(struct ib_mad_agent_private *mad_agent_priv,
 			 * No receiving agent so drop packet and
 			 * generate send completion.
 			 */
-			kmem_cache_free(ib_mad_cache, mad_priv);
+			kfree(mad_priv);
 			break;
 		}
 		local->mad_priv = mad_priv;
 		local->recv_mad_agent = recv_mad_agent;
 		break;
 	default:
-		kmem_cache_free(ib_mad_cache, mad_priv);
+		kfree(mad_priv);
 		kfree(local);
 		ret = -EINVAL;
 		goto out;
@@ -1237,7 +1243,7 @@ void ib_free_recv_mad(struct ib_mad_recv_wc *mad_recv_wc)
 					    recv_wc);
 		priv = container_of(mad_priv_hdr, struct ib_mad_private,
 				    header);
-		kmem_cache_free(ib_mad_cache, priv);
+		kfree(priv);
 	}
 }
 EXPORT_SYMBOL(ib_free_recv_mad);
@@ -1924,6 +1930,11 @@ static void ib_mad_complete_recv(struct ib_mad_agent_private *mad_agent_priv,
 	}
 }
 
+static size_t mad_recv_buf_size(struct ib_device *dev)
+{
+	return(sizeof(struct ib_grh) + dev->attributes.mad_size);
+}
+
 static bool generate_unmatched_resp(struct ib_mad_private *recv,
 				    struct ib_mad_private *response)
 {
@@ -1964,8 +1975,7 @@ static void ib_mad_recv_done_handler(struct ib_mad_port_private *port_priv,
 	recv = container_of(mad_priv_hdr, struct ib_mad_private, header);
 	ib_dma_unmap_single(port_priv->device,
 			    recv->header.mapping,
-			    sizeof(struct ib_mad_private) -
-			      sizeof(struct ib_mad_private_header),
+			    mad_recv_buf_size(port_priv->device),
 			    DMA_FROM_DEVICE);
 
 	/* Setup MAD receive work completion from "normal" work completion */
@@ -1982,7 +1992,7 @@ static void ib_mad_recv_done_handler(struct ib_mad_port_private *port_priv,
 	if (!validate_mad(&recv->mad.mad.mad_hdr, qp_info->qp->qp_num))
 		goto out;
 
-	response = kmem_cache_alloc(ib_mad_cache, GFP_KERNEL);
+	response = alloc_mad_priv(port_priv->device);
 	if (!response) {
 		dev_err(&port_priv->device->dev,
 			"ib_mad_recv_done_handler no memory for response buffer\n");
@@ -2075,7 +2085,7 @@ out:
 	if (response) {
 		ib_mad_post_receive_mads(qp_info, response);
 		if (recv)
-			kmem_cache_free(ib_mad_cache, recv);
+			kfree(recv);
 	} else
 		ib_mad_post_receive_mads(qp_info, recv);
 }
@@ -2535,7 +2545,7 @@ local_send_completion:
 		spin_lock_irqsave(&mad_agent_priv->lock, flags);
 		atomic_dec(&mad_agent_priv->refcount);
 		if (free_mad)
-			kmem_cache_free(ib_mad_cache, local->mad_priv);
+			kfree(local->mad_priv);
 		kfree(local);
 	}
 	spin_unlock_irqrestore(&mad_agent_priv->lock, flags);
@@ -2664,7 +2674,7 @@ static int ib_mad_post_receive_mads(struct ib_mad_qp_info *qp_info,
 			mad_priv = mad;
 			mad = NULL;
 		} else {
-			mad_priv = kmem_cache_alloc(ib_mad_cache, GFP_KERNEL);
+			mad_priv = alloc_mad_priv(qp_info->port_priv->device);
 			if (!mad_priv) {
 				dev_err(&qp_info->port_priv->device->dev,
 					"No memory for receive buffer\n");
@@ -2674,8 +2684,7 @@ static int ib_mad_post_receive_mads(struct ib_mad_qp_info *qp_info,
 		}
 		sg_list.addr = ib_dma_map_single(qp_info->port_priv->device,
 						 &mad_priv->grh,
-						 sizeof *mad_priv -
-						   sizeof mad_priv->header,
+						 mad_recv_buf_size(qp_info->port_priv->device),
 						 DMA_FROM_DEVICE);
 		if (unlikely(ib_dma_mapping_error(qp_info->port_priv->device,
 						  sg_list.addr))) {
@@ -2699,10 +2708,9 @@ static int ib_mad_post_receive_mads(struct ib_mad_qp_info *qp_info,
 			spin_unlock_irqrestore(&recv_queue->lock, flags);
 			ib_dma_unmap_single(qp_info->port_priv->device,
 					    mad_priv->header.mapping,
-					    sizeof *mad_priv -
-					      sizeof mad_priv->header,
+					    mad_recv_buf_size(qp_info->port_priv->device),
 					    DMA_FROM_DEVICE);
-			kmem_cache_free(ib_mad_cache, mad_priv);
+			kfree(mad_priv);
 			dev_err(&qp_info->port_priv->device->dev,
 				"ib_post_recv failed: %d\n", ret);
 			break;
@@ -2739,10 +2747,9 @@ static void cleanup_recv_queue(struct ib_mad_qp_info *qp_info)
 
 		ib_dma_unmap_single(qp_info->port_priv->device,
 				    recv->header.mapping,
-				    sizeof(struct ib_mad_private) -
-				      sizeof(struct ib_mad_private_header),
+				    mad_recv_buf_size(qp_info->port_priv->device),
 				    DMA_FROM_DEVICE);
-		kmem_cache_free(ib_mad_cache, recv);
+		kfree(recv);
 	}
 
 	qp_info->recv_queue.count = 0;
@@ -3138,45 +3145,25 @@ static struct ib_client mad_client = {
 
 static int __init ib_mad_init_module(void)
 {
-	int ret;
-
 	mad_recvq_size = min(mad_recvq_size, IB_MAD_QP_MAX_SIZE);
 	mad_recvq_size = max(mad_recvq_size, IB_MAD_QP_MIN_SIZE);
 
 	mad_sendq_size = min(mad_sendq_size, IB_MAD_QP_MAX_SIZE);
 	mad_sendq_size = max(mad_sendq_size, IB_MAD_QP_MIN_SIZE);
 
-	ib_mad_cache = kmem_cache_create("ib_mad",
-					 sizeof(struct ib_mad_private),
-					 0,
-					 SLAB_HWCACHE_ALIGN,
-					 NULL);
-	if (!ib_mad_cache) {
-		pr_err("Couldn't create ib_mad cache\n");
-		ret = -ENOMEM;
-		goto error1;
-	}
-
 	INIT_LIST_HEAD(&ib_mad_port_list);
 
 	if (ib_register_client(&mad_client)) {
 		pr_err("Couldn't register ib_mad client\n");
-		ret = -EINVAL;
-		goto error2;
+		return(-EINVAL);
 	}
 
 	return 0;
-
-error2:
-	kmem_cache_destroy(ib_mad_cache);
-error1:
-	return ret;
 }
 
 static void __exit ib_mad_cleanup_module(void)
 {
 	ib_unregister_client(&mad_client);
-	kmem_cache_destroy(ib_mad_cache);
 }
 
 module_init(ib_mad_init_module);
-- 
1.7.1

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