IPoIB: Make send and receive queue sizes tunable

Make IPoIB's send and receive queue sizes tunable via module
parameters ("send_queue_size" and "recv_queue_size").  This allows the
queue sizes to be enlarged to fix disastrously bad performance on some
platforms and workloads, without bloating memory usage when large
queues aren't needed.

Signed-off-by: Shirley Ma <xma@us.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 22 insertions, 6 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 9cb9e430aaaf..5bf7e263454b 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -41,6 +41,7 @@
 #include <linux/init.h>
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
+#include <linux/kernel.h>
 
 #include <linux/if_arp.h>       /* For ARPHRD_xxx */
 
@@ -53,6 +54,14 @@ MODULE_AUTHOR("Roland Dreier");
 MODULE_DESCRIPTION("IP-over-InfiniBand net driver");
 MODULE_LICENSE("Dual BSD/GPL");
 
+int ipoib_sendq_size __read_mostly = IPOIB_TX_RING_SIZE;
+int ipoib_recvq_size __read_mostly = IPOIB_RX_RING_SIZE;
+
+module_param_named(send_queue_size, ipoib_sendq_size, int, 0444);
+MODULE_PARM_DESC(send_queue_size, "Number of descriptors in send queue");
+module_param_named(recv_queue_size, ipoib_recvq_size, int, 0444);
+MODULE_PARM_DESC(recv_queue_size, "Number of descriptors in receive queue");
+
 #ifdef CONFIG_INFINIBAND_IPOIB_DEBUG
 int ipoib_debug_level;
 
@@ -795,20 +804,19 @@ int ipoib_dev_init(struct net_device *dev, struct ib_device *ca, int port)
         struct ipoib_dev_priv *priv = netdev_priv(dev);
 
         /* Allocate RX/TX "rings" to hold queued skbs */
-
-        priv->rx_ring = kzalloc(IPOIB_RX_RING_SIZE * sizeof (struct ipoib_rx_buf),
+        priv->rx_ring = kzalloc(ipoib_recvq_size * sizeof *priv->rx_ring,
                                 GFP_KERNEL);
         if (!priv->rx_ring) {
                 printk(KERN_WARNING "%s: failed to allocate RX ring (%d entries)\n",
-                       ca->name, IPOIB_RX_RING_SIZE);
+                       ca->name, ipoib_recvq_size);
                 goto out;
         }
 
-        priv->tx_ring = kzalloc(IPOIB_TX_RING_SIZE * sizeof (struct ipoib_tx_buf),
+        priv->tx_ring = kzalloc(ipoib_sendq_size * sizeof *priv->tx_ring,
                                 GFP_KERNEL);
         if (!priv->tx_ring) {
                 printk(KERN_WARNING "%s: failed to allocate TX ring (%d entries)\n",
-                       ca->name, IPOIB_TX_RING_SIZE);
+                       ca->name, ipoib_sendq_size);
                 goto out_rx_ring_cleanup;
         }
 
@@ -876,7 +884,7 @@ static void ipoib_setup(struct net_device *dev)
         dev->hard_header_len     = IPOIB_ENCAP_LEN + INFINIBAND_ALEN;
         dev->addr_len            = INFINIBAND_ALEN;
         dev->type                = ARPHRD_INFINIBAND;
-        dev->tx_queue_len        = IPOIB_TX_RING_SIZE * 2;
+        dev->tx_queue_len        = ipoib_sendq_size * 2;
         dev->features            = NETIF_F_VLAN_CHALLENGED | NETIF_F_LLTX;
 
         /* MTU will be reset when mcast join happens */
@@ -1128,6 +1136,14 @@ static int __init ipoib_init_module(void)
 {
         int ret;
 
+        ipoib_recvq_size = roundup_pow_of_two(ipoib_recvq_size);
+        ipoib_recvq_size = min(ipoib_recvq_size, IPOIB_MAX_QUEUE_SIZE);
+        ipoib_recvq_size = max(ipoib_recvq_size, IPOIB_MIN_QUEUE_SIZE);
+
+        ipoib_sendq_size = roundup_pow_of_two(ipoib_sendq_size);
+        ipoib_sendq_size = min(ipoib_sendq_size, IPOIB_MAX_QUEUE_SIZE);
+        ipoib_sendq_size = max(ipoib_sendq_size, IPOIB_MIN_QUEUE_SIZE);
+
         ret = ipoib_register_debugfs();
         if (ret)
                 return ret;