> Quoting Michael S. Tsirkin <[EMAIL PROTECTED]>:
> Subject: [PATCH RFC] use common cq for ipoib cm send side
>
> The following untested patch moves all TX processing in IPoIB CM to common CQ.
> This should help reduce the number of interrupts for bi-directional traffic
> (such as TCP). Is this a good idea? What do others think?
>
> Signed-off-by: Michael S. Tsirkin <[EMAIL PROTECTED]>
FYI, this was just thinking aloud. The version below works fine here but the
performance gain seems to be very small (about 1%). The gain with NAPI might
be bigger but this is yet to be tested. I'll continue looking into this.
Feedback wellcome.
ipoib.h | 10 +++++--
ipoib_cm.c | 78 +++++++++++++++--------------------------------------------
ipoib_ib.c | 28 ++++++++++++---------
ipoib_main.c | 2 -
4 files changed, 45 insertions(+), 73 deletions(-)
------------
Use common CQ for all TX QPs: keep a per-device counter out outstanding
tx WRs, and stop the interface when this counter reaches the send queue size, to
avoid CQ overruns.
Signed-off-by: Michael S. Tsirkin <[EMAIL PROTECTED]>
---
diff --git a/drivers/infiniband/ulp/ipoib/ipoib.h
b/drivers/infiniband/ulp/ipoib/ipoib.h
index eb885ee..ef703c7 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib.h
+++ b/drivers/infiniband/ulp/ipoib/ipoib.h
@@ -99,9 +99,9 @@ enum {
#define IPOIB_OP_RECV (1ul << 31)
#ifdef CONFIG_INFINIBAND_IPOIB_CM
-#define IPOIB_CM_OP_SRQ (1ul << 30)
+#define IPOIB_OP_CM (1ul << 30)
#else
-#define IPOIB_CM_OP_SRQ (0)
+#define IPOIB_OP_CM (0)
#endif
/* structs */
@@ -144,7 +144,6 @@ struct ipoib_cm_rx {
struct ipoib_cm_tx {
struct ib_cm_id *id;
- struct ib_cq *cq;
struct ib_qp *qp;
struct list_head list;
struct net_device *dev;
@@ -233,6 +232,7 @@ struct ipoib_dev_priv {
unsigned tx_tail;
struct ib_sge tx_sge;
struct ib_send_wr tx_wr;
+ unsigned tx_outstanding;
struct ib_wc ibwc[IPOIB_NUM_WC];
@@ -439,6 +439,7 @@ void ipoib_cm_destroy_tx(struct ipoib_cm_tx *tx);
void ipoib_cm_skb_too_long(struct net_device* dev, struct sk_buff *skb,
unsigned int mtu);
void ipoib_cm_handle_rx_wc(struct net_device *dev, struct ib_wc *wc);
+void ipoib_cm_handle_tx_wc(struct net_device *dev, struct ib_wc *wc);
#else
struct ipoib_cm_tx;
@@ -527,6 +528,9 @@ static inline void ipoib_cm_handle_rx_wc(struct net_device
*dev, struct ib_wc *w
{
}
+static inline void ipoib_cm_handle_tx_wc(struct net_device *dev, struct ib_wc
*wc)
+{
+}
#endif
#ifdef CONFIG_INFINIBAND_IPOIB_DEBUG
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
index 8ee6f06..af36562 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
@@ -85,7 +85,7 @@ static int ipoib_cm_post_receive(struct net_device *dev, int
id)
struct ib_recv_wr *bad_wr;
int i, ret;
- priv->cm.rx_wr.wr_id = id | IPOIB_CM_OP_SRQ;
+ priv->cm.rx_wr.wr_id = id | IPOIB_OP_CM | IPOIB_OP_RECV;
for (i = 0; i < IPOIB_CM_RX_SG; ++i)
priv->cm.rx_sge[i].addr = priv->cm.srq_ring[id].mapping[i];
@@ -346,7 +346,7 @@ static void skb_put_frags(struct sk_buff *skb, unsigned int
hdr_space,
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;
+ unsigned int wr_id = wc->wr_id & ~(IPOIB_OP_CM | IPOIB_OP_RECV);
struct sk_buff *skb;
struct ipoib_cm_rx *p;
unsigned long flags;
@@ -433,7 +433,7 @@ static inline int post_send(struct ipoib_dev_priv *priv,
priv->tx_sge.addr = addr;
priv->tx_sge.length = len;
- priv->tx_wr.wr_id = wr_id;
+ priv->tx_wr.wr_id = wr_id | IPOIB_OP_CM;
return ib_post_send(tx->qp, &priv->tx_wr, &bad_wr);
}
@@ -484,20 +484,19 @@ void ipoib_cm_send(struct net_device *dev, struct sk_buff
*skb, struct ipoib_cm_
dev->trans_start = jiffies;
++tx->tx_head;
- if (tx->tx_head - tx->tx_tail == ipoib_sendq_size) {
+ if (++priv->tx_outstanding == ipoib_sendq_size) {
ipoib_dbg(priv, "TX ring 0x%x full, stopping kernel net
queue\n",
tx->qp->qp_num);
netif_stop_queue(dev);
- set_bit(IPOIB_FLAG_NETIF_STOPPED, &tx->flags);
}
}
}
-static void ipoib_cm_handle_tx_wc(struct net_device *dev, struct ipoib_cm_tx
*tx,
- struct ib_wc *wc)
+void ipoib_cm_handle_tx_wc(struct net_device *dev, struct ib_wc *wc)
{
struct ipoib_dev_priv *priv = netdev_priv(dev);
- unsigned int wr_id = wc->wr_id;
+ struct ipoib_cm_tx *tx = wc->qp->qp_context;
+ unsigned int wr_id = wc->wr_id & ~IPOIB_OP_CM;
struct ipoib_tx_buf *tx_req;
unsigned long flags;
@@ -522,11 +521,10 @@ static void ipoib_cm_handle_tx_wc(struct net_device *dev,
struct ipoib_cm_tx *tx
spin_lock_irqsave(&priv->tx_lock, flags);
++tx->tx_tail;
- if (unlikely(test_bit(IPOIB_FLAG_NETIF_STOPPED, &tx->flags)) &&
- tx->tx_head - tx->tx_tail <= ipoib_sendq_size >> 1) {
- clear_bit(IPOIB_FLAG_NETIF_STOPPED, &tx->flags);
+ if (unlikely(--priv->tx_outstanding == ipoib_sendq_size >> 1) &&
+ netif_queue_stopped(dev) &&
+ test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
netif_wake_queue(dev);
- }
if (wc->status != IB_WC_SUCCESS &&
wc->status != IB_WC_WR_FLUSH_ERR) {
@@ -549,11 +547,6 @@ static void ipoib_cm_handle_tx_wc(struct net_device *dev,
struct ipoib_cm_tx *tx
tx->neigh = NULL;
}
- /* queue would be re-started anyway when TX is destroyed,
- * but it makes sense to do it ASAP here. */
- if (test_and_clear_bit(IPOIB_FLAG_NETIF_STOPPED, &tx->flags))
- netif_wake_queue(dev);
-
if (test_and_clear_bit(IPOIB_FLAG_INITIALIZED, &tx->flags)) {
list_move(&tx->list, &priv->cm.reap_list);
queue_work(ipoib_workqueue, &priv->cm.reap_task);
@@ -567,19 +560,6 @@ static void ipoib_cm_handle_tx_wc(struct net_device *dev,
struct ipoib_cm_tx *tx
spin_unlock_irqrestore(&priv->tx_lock, flags);
}
-static void ipoib_cm_tx_completion(struct ib_cq *cq, void *tx_ptr)
-{
- struct ipoib_cm_tx *tx = tx_ptr;
- int n, i;
-
- ib_req_notify_cq(cq, IB_CQ_NEXT_COMP);
- do {
- n = ib_poll_cq(cq, IPOIB_NUM_WC, tx->ibwc);
- for (i = 0; i < n; ++i)
- ipoib_cm_handle_tx_wc(tx->dev, tx, tx->ibwc + i);
- } while (n == IPOIB_NUM_WC);
-}
-
int ipoib_cm_dev_open(struct net_device *dev)
{
struct ipoib_dev_priv *priv = netdev_priv(dev);
@@ -699,17 +679,18 @@ static int ipoib_cm_rep_handler(struct ib_cm_id *cm_id,
struct ib_cm_event *even
return 0;
}
-static struct ib_qp *ipoib_cm_create_tx_qp(struct net_device *dev, struct
ib_cq *cq)
+static struct ib_qp *ipoib_cm_create_tx_qp(struct net_device *dev, struct
ipoib_cm_tx *tx)
{
struct ipoib_dev_priv *priv = netdev_priv(dev);
struct ib_qp_init_attr attr = {};
attr.recv_cq = priv->cq;
+ attr.send_cq = priv->cq;
attr.srq = priv->cm.srq;
attr.cap.max_send_wr = ipoib_sendq_size;
attr.cap.max_send_sge = 1;
attr.sq_sig_type = IB_SIGNAL_ALL_WR;
attr.qp_type = IB_QPT_RC;
- attr.send_cq = cq;
+ attr.qp_context = tx;
return ib_create_qp(priv->pd, &attr);
}
@@ -789,21 +770,7 @@ static int ipoib_cm_tx_init(struct ipoib_cm_tx *p, u32 qpn,
goto err_tx;
}
- p->cq = ib_create_cq(priv->ca, ipoib_cm_tx_completion, NULL, p,
- ipoib_sendq_size + 1);
- if (IS_ERR(p->cq)) {
- ret = PTR_ERR(p->cq);
- ipoib_warn(priv, "failed to allocate tx cq: %d\n", ret);
- goto err_cq;
- }
-
- ret = ib_req_notify_cq(p->cq, IB_CQ_NEXT_COMP);
- if (ret) {
- ipoib_warn(priv, "failed to request completion notification:
%d\n", ret);
- goto err_req_notify;
- }
-
- p->qp = ipoib_cm_create_tx_qp(p->dev, p->cq);
+ p->qp = ipoib_cm_create_tx_qp(p->dev, p);
if (IS_ERR(p->qp)) {
ret = PTR_ERR(p->qp);
ipoib_warn(priv, "failed to allocate tx qp: %d\n", ret);
@@ -840,12 +807,8 @@ err_modify:
err_id:
p->id = NULL;
ib_destroy_qp(p->qp);
-err_req_notify:
err_qp:
p->qp = NULL;
- ib_destroy_cq(p->cq);
-err_cq:
- p->cq = NULL;
err_tx:
return ret;
}
@@ -854,6 +817,7 @@ static void ipoib_cm_tx_destroy(struct ipoib_cm_tx *p)
{
struct ipoib_dev_priv *priv = netdev_priv(p->dev);
struct ipoib_tx_buf *tx_req;
+ unsigned long flags;
ipoib_dbg(priv, "Destroy active connection 0x%x head 0x%x tail 0x%x\n",
p->qp ? p->qp->qp_num : 0, p->tx_head, p->tx_tail);
@@ -864,12 +828,6 @@ static void ipoib_cm_tx_destroy(struct ipoib_cm_tx *p)
if (p->qp)
ib_destroy_qp(p->qp);
- if (p->cq)
- ib_destroy_cq(p->cq);
-
- if (test_bit(IPOIB_FLAG_NETIF_STOPPED, &p->flags))
- netif_wake_queue(p->dev);
-
if (p->tx_ring) {
while ((int) p->tx_tail - (int) p->tx_head < 0) {
tx_req = &p->tx_ring[p->tx_tail & (ipoib_sendq_size -
1)];
@@ -877,6 +835,12 @@ static void ipoib_cm_tx_destroy(struct ipoib_cm_tx *p)
DMA_TO_DEVICE);
dev_kfree_skb_any(tx_req->skb);
++p->tx_tail;
+ spin_lock_irqsave(&priv->tx_lock, flags);
+ if (unlikely(--priv->tx_outstanding == ipoib_sendq_size
>> 1) &&
+ netif_queue_stopped(p->dev) &&
+ test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
+ netif_wake_queue(p->dev);
+ spin_unlock_irqrestore(&priv->tx_lock, flags);
}
kfree(p->tx_ring);
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
index f2aa923..19a3d3e 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
@@ -266,11 +266,10 @@ static void ipoib_ib_handle_tx_wc(struct net_device *dev,
struct ib_wc *wc)
spin_lock_irqsave(&priv->tx_lock, flags);
++priv->tx_tail;
- if (unlikely(test_bit(IPOIB_FLAG_NETIF_STOPPED, &priv->flags)) &&
- priv->tx_head - priv->tx_tail <= ipoib_sendq_size >> 1) {
- clear_bit(IPOIB_FLAG_NETIF_STOPPED, &priv->flags);
+ if (unlikely(--priv->tx_outstanding == ipoib_sendq_size >> 1) &&
+ netif_queue_stopped(dev) &&
+ test_bit(IPOIB_FLAG_ADMIN_UP, &priv->flags))
netif_wake_queue(dev);
- }
spin_unlock_irqrestore(&priv->tx_lock, flags);
if (wc->status != IB_WC_SUCCESS &&
@@ -282,12 +281,17 @@ static void ipoib_ib_handle_tx_wc(struct net_device *dev,
struct ib_wc *wc)
static void ipoib_ib_handle_wc(struct net_device *dev, struct ib_wc *wc)
{
- if (wc->wr_id & IPOIB_CM_OP_SRQ)
- ipoib_cm_handle_rx_wc(dev, wc);
- else if (wc->wr_id & IPOIB_OP_RECV)
- ipoib_ib_handle_rx_wc(dev, wc);
- else
- ipoib_ib_handle_tx_wc(dev, wc);
+ if (wc->wr_id & IPOIB_OP_CM) {
+ if (wc->wr_id & IPOIB_OP_RECV)
+ ipoib_cm_handle_rx_wc(dev, wc);
+ else
+ ipoib_cm_handle_tx_wc(dev, wc);
+ } else {
+ if (wc->wr_id & IPOIB_OP_RECV)
+ ipoib_ib_handle_rx_wc(dev, wc);
+ else
+ ipoib_ib_handle_tx_wc(dev, wc);
+ }
}
void ipoib_ib_completion(struct ib_cq *cq, void *dev_ptr)
@@ -370,10 +374,9 @@ void ipoib_send(struct net_device *dev, struct sk_buff
*skb,
address->last_send = priv->tx_head;
++priv->tx_head;
- if (priv->tx_head - priv->tx_tail == ipoib_sendq_size) {
+ if (++priv->tx_outstanding == ipoib_sendq_size) {
ipoib_dbg(priv, "TX ring full, stopping kernel net
queue\n");
netif_stop_queue(dev);
- set_bit(IPOIB_FLAG_NETIF_STOPPED, &priv->flags);
}
}
}
@@ -549,6 +552,7 @@ int ipoib_ib_dev_stop(struct net_device *dev)
DMA_TO_DEVICE);
dev_kfree_skb_any(tx_req->skb);
++priv->tx_tail;
+ --priv->tx_outstanding;
}
for (i = 0; i < ipoib_recvq_size; ++i) {
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c
b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 19e82db..7c7b136 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -900,7 +900,7 @@ int ipoib_dev_init(struct net_device *dev, struct ib_device
*ca, int port)
goto out_rx_ring_cleanup;
}
- /* priv->tx_head & tx_tail are already 0 */
+ /* priv->tx_head, tx_tail & tx_outstanding are already 0 */
if (ipoib_ib_dev_init(dev, ca, port))
goto out_tx_ring_cleanup;
--
MST
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