[openib-general] [PATCH for-2.6.21] IPoIB/cm: improve small message bandwidth
Michael S. Tsirkin
mst at mellanox.co.il
Tue Feb 20 10:17:55 PST 2007
Avoid overhead of freeing/reallocating and mapping/unmapping for dma
for pages that have not been written to by hardware.
Signed-off-by: Michael S. Tsirkin <mst at mellanox.co.il>
---
This gives >10% boost in BW for message sizes up to 32K. Please queue for 2.6.21.
before:
# ./netperf-2.4.2/src/netperf -f M -H 11.4.3.68 -c -C -- -m 32000
TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 11.4.3.68 (11.4.3.68) port 0 AF_INET : demo
Recv Send Send Utilization Service Demand
Socket Socket Message Elapsed Send Recv Send Recv
Size Size Size Time Throughput local remote local remote
bytes bytes bytes secs. MBytes /s % S % S us/KB us/KB
87380 16384 32000 10.00 716.23 26.22 23.94 1.430 1.306
after:
# ./netperf-2.4.2/src/netperf -f M -H 11.4.3.68 -c -C -- -m 32000
TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 11.4.3.68 (11.4.3.68) port 0 AF_INET : demo
Recv Send Send Utilization Service Demand
Socket Socket Message Elapsed Send Recv Send Recv
Size Size Size Time Throughput local remote local remote
bytes bytes bytes secs. MBytes /s % S % S us/KB us/KB
87380 16384 32000 10.00 888.67 24.13 25.08 1.061 1.102
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
index 8ee6f06..a23c8e3 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
@@ -68,14 +68,14 @@ struct ipoib_cm_id {
static int ipoib_cm_tx_handler(struct ib_cm_id *cm_id,
struct ib_cm_event *event);
-static void ipoib_cm_dma_unmap_rx(struct ipoib_dev_priv *priv,
+static void ipoib_cm_dma_unmap_rx(struct ipoib_dev_priv *priv, int frags,
u64 mapping[IPOIB_CM_RX_SG])
{
int i;
ib_dma_unmap_single(priv->ca, mapping[0], IPOIB_CM_HEAD_SIZE, DMA_FROM_DEVICE);
- for (i = 0; i < IPOIB_CM_RX_SG - 1; ++i)
+ for (i = 0; i < frags; ++i)
ib_dma_unmap_single(priv->ca, mapping[i + 1], PAGE_SIZE, DMA_FROM_DEVICE);
}
@@ -93,7 +93,8 @@ static int ipoib_cm_post_receive(struct net_device *dev, int id)
ret = ib_post_srq_recv(priv->cm.srq, &priv->cm.rx_wr, &bad_wr);
if (unlikely(ret)) {
ipoib_warn(priv, "post srq failed for buf %d (%d)\n", id, ret);
- ipoib_cm_dma_unmap_rx(priv, priv->cm.srq_ring[id].mapping);
+ ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
+ priv->cm.srq_ring[id].mapping);
dev_kfree_skb_any(priv->cm.srq_ring[id].skb);
priv->cm.srq_ring[id].skb = NULL;
}
@@ -101,8 +102,8 @@ static int ipoib_cm_post_receive(struct net_device *dev, int id)
return ret;
}
-static int ipoib_cm_alloc_rx_skb(struct net_device *dev, int id,
- u64 mapping[IPOIB_CM_RX_SG])
+static struct sk_buff *ipoib_cm_alloc_rx_skb(struct net_device *dev, int id, int frags,
+ u64 mapping[IPOIB_CM_RX_SG])
{
struct ipoib_dev_priv *priv = netdev_priv(dev);
struct sk_buff *skb;
@@ -110,7 +111,7 @@ static int ipoib_cm_alloc_rx_skb(struct net_device *dev, int id,
skb = dev_alloc_skb(IPOIB_CM_HEAD_SIZE + 12);
if (unlikely(!skb))
- return -ENOMEM;
+ return NULL;
/*
* IPoIB adds a 4 byte header. So we need 12 more bytes to align the
@@ -122,10 +123,10 @@ static int ipoib_cm_alloc_rx_skb(struct net_device *dev, int id,
DMA_FROM_DEVICE);
if (unlikely(ib_dma_mapping_error(priv->ca, mapping[0]))) {
dev_kfree_skb_any(skb);
- return -EIO;
+ return NULL;
}
- for (i = 0; i < IPOIB_CM_RX_SG - 1; i++) {
+ for (i = 0; i < frags; i++) {
struct page *page = alloc_page(GFP_ATOMIC);
if (!page)
@@ -139,7 +140,7 @@ static int ipoib_cm_alloc_rx_skb(struct net_device *dev, int id,
}
priv->cm.srq_ring[id].skb = skb;
- return 0;
+ return skb;
partial_error:
@@ -148,8 +149,8 @@ partial_error:
for (; i >= 0; --i)
ib_dma_unmap_single(priv->ca, mapping[i + 1], PAGE_SIZE, DMA_FROM_DEVICE);
- dev_kfree_skb_any(skb);
- return -ENOMEM;
+ dev_kfree_skb_any(skb);
+ return NULL;
}
static struct ib_qp *ipoib_cm_create_rx_qp(struct net_device *dev,
@@ -312,7 +313,7 @@ static int ipoib_cm_rx_handler(struct ib_cm_id *cm_id,
}
/* Adjust length of skb with fragments to match received data */
static void skb_put_frags(struct sk_buff *skb, unsigned int hdr_space,
- unsigned int length)
+ unsigned int length, struct sk_buff *toskb)
{
int i, num_frags;
unsigned int size;
@@ -329,7 +330,7 @@ static void skb_put_frags(struct sk_buff *skb, unsigned int hdr_space,
if (length == 0) {
/* don't need this page */
- __free_page(frag->page);
+ skb_fill_page_desc(toskb, i, frag->page, 0, PAGE_SIZE);
--skb_shinfo(skb)->nr_frags;
} else {
size = min(length, (unsigned) PAGE_SIZE);
@@ -347,10 +348,11 @@ void ipoib_cm_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
{
struct ipoib_dev_priv *priv = netdev_priv(dev);
unsigned int wr_id = wc->wr_id & ~IPOIB_CM_OP_SRQ;
- struct sk_buff *skb;
+ struct sk_buff *skb, *newskb;
struct ipoib_cm_rx *p;
unsigned long flags;
u64 mapping[IPOIB_CM_RX_SG];
+ int frags;
ipoib_dbg_data(priv, "cm recv completion: id %d, op %d, status: %d\n",
wr_id, wc->opcode, wc->status);
@@ -386,7 +388,11 @@ void ipoib_cm_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
}
}
- if (unlikely(ipoib_cm_alloc_rx_skb(dev, wr_id, mapping))) {
+ frags = PAGE_ALIGN(wc->byte_len - min(wc->byte_len,
+ (unsigned)IPOIB_CM_HEAD_SIZE)) / PAGE_SIZE;
+
+ newskb = ipoib_cm_alloc_rx_skb(dev, wr_id, frags, mapping);
+ if (unlikely(!newskb)) {
/*
* If we can't allocate a new RX buffer, dump
* this packet and reuse the old buffer.
@@ -396,13 +402,13 @@ void ipoib_cm_handle_rx_wc(struct net_device *dev, struct ib_wc *wc)
goto repost;
}
- ipoib_cm_dma_unmap_rx(priv, priv->cm.srq_ring[wr_id].mapping);
- memcpy(priv->cm.srq_ring[wr_id].mapping, mapping, sizeof mapping);
+ ipoib_cm_dma_unmap_rx(priv, frags, priv->cm.srq_ring[wr_id].mapping);
+ memcpy(priv->cm.srq_ring[wr_id].mapping, mapping, (frags + 1) * sizeof *mapping);
ipoib_dbg_data(priv, "received %d bytes, SLID 0x%04x\n",
wc->byte_len, wc->slid);
- skb_put_frags(skb, IPOIB_CM_HEAD_SIZE, wc->byte_len);
+ skb_put_frags(skb, IPOIB_CM_HEAD_SIZE, wc->byte_len, newskb);
skb->protocol = ((struct ipoib_header *) skb->data)->proto;
skb->mac.raw = skb->data;
@@ -1196,7 +1202,8 @@ int ipoib_cm_dev_init(struct net_device *dev)
priv->cm.rx_wr.num_sge = IPOIB_CM_RX_SG;
for (i = 0; i < ipoib_recvq_size; ++i) {
- if (ipoib_cm_alloc_rx_skb(dev, i, priv->cm.srq_ring[i].mapping)) {
+ if (!ipoib_cm_alloc_rx_skb(dev, i, IPOIB_CM_RX_SG - 1,
+ priv->cm.srq_ring[i].mapping)) {
ipoib_warn(priv, "failed to allocate receive buffer %d\n", i);
ipoib_cm_dev_cleanup(dev);
return -ENOMEM;
@@ -1231,7 +1238,8 @@ void ipoib_cm_dev_cleanup(struct net_device *dev)
return;
for (i = 0; i < ipoib_recvq_size; ++i)
if (priv->cm.srq_ring[i].skb) {
- ipoib_cm_dma_unmap_rx(priv, priv->cm.srq_ring[i].mapping);
+ ipoib_cm_dma_unmap_rx(priv, IPOIB_CM_RX_SG - 1,
+ priv->cm.srq_ring[i].mapping);
dev_kfree_skb_any(priv->cm.srq_ring[i].skb);
priv->cm.srq_ring[i].skb = NULL;
}
--
MST
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