svn commit: r258584 - in stable/9/sys: dev/bxe dev/oce ofed/drivers/net/mlx4
Xin LI
delphij at FreeBSD.org
Mon Nov 25 20:01:35 UTC 2013
Author: delphij
Date: Mon Nov 25 20:01:34 2013
New Revision: 258584
URL: http://svnweb.freebsd.org/changeset/base/258584
Log:
MFC r246482 (rrs) + r246581:
This fixes a out-of-order problem with several of the newer
drivers. The basic problem was that the driver was pulling
the mbuf off the drbr ring and then when sending with xmit(),
encounting a full transmit ring. Thus the lower layer xmit()
function would return an error, and the drivers would then
append the data back on to the ring. For TCP this is a
horrible scenario sure to bring on a fast-retransmit.
The fix is to use drbr_peek() to pull the data pointer but
not remove it from the ring. If it fails then we either call
the new drbr_putback or drbr_advance method. Advance moves
it forward (we do this sometimes when the xmit() function
frees the mbuf). When we succeed we always call advance.
The putback will always copy the mbuf back to the top of the
ring. Note that the putback *cannot* be used with a
drbr_dequeue() only with drbr_peek(). We most of the time,
in putback, would not need to copy it back since most likey
the mbuf is still the same, but sometimes xmit() functions
will change the mbuf via a pullup or other call. So the
optimial case for the single consumer is to always copy it
back. If we ever do a multiple_consumer (for lagg?) we
will need a test and atomic in the put back possibly a
seperate putback_mc() in the ring buf.
Reviewed by: jhb at freebsd.org, jlv at freebsd.org
Modified:
stable/9/sys/dev/bxe/if_bxe.c
stable/9/sys/dev/oce/oce_if.c
stable/9/sys/ofed/drivers/net/mlx4/en_tx.c
Directory Properties:
stable/9/sys/ (props changed)
stable/9/sys/dev/ (props changed)
Modified: stable/9/sys/dev/bxe/if_bxe.c
==============================================================================
--- stable/9/sys/dev/bxe/if_bxe.c Mon Nov 25 19:53:46 2013 (r258583)
+++ stable/9/sys/dev/bxe/if_bxe.c Mon Nov 25 20:01:34 2013 (r258584)
@@ -9501,24 +9501,15 @@ bxe_tx_mq_start_locked(struct ifnet *ifp
BXE_FP_LOCK_ASSERT(fp);
- if (m == NULL) {
- /* No new work, check for pending frames. */
- next = drbr_dequeue(ifp, fp->br);
- } else if (drbr_needs_enqueue(ifp, fp->br)) {
- /* Both new and pending work, maintain packet order. */
+ if (m != NULL) {
rc = drbr_enqueue(ifp, fp->br, m);
if (rc != 0) {
fp->tx_soft_errors++;
goto bxe_tx_mq_start_locked_exit;
}
- next = drbr_dequeue(ifp, fp->br);
- } else
- /* New work only, nothing pending. */
- next = m;
-
+ }
/* Keep adding entries while there are frames to send. */
- while (next != NULL) {
-
+ while ((next = drbr_peek(ifp, fp->br)) != NULL) {
/* The transmit mbuf now belongs to us, keep track of it. */
fp->tx_mbuf_alloc++;
@@ -9532,23 +9523,22 @@ bxe_tx_mq_start_locked(struct ifnet *ifp
if (__predict_false(rc != 0)) {
fp->tx_encap_failures++;
/* Very Bad Frames(tm) may have been dropped. */
- if (next != NULL) {
+ if (next == NULL) {
+ drbr_advance(ifp, fp->br);
+ } else {
+ drbr_putback(ifp, fp->br, next);
/*
* Mark the TX queue as full and save
* the frame.
*/
ifp->if_drv_flags |= IFF_DRV_OACTIVE;
fp->tx_frame_deferred++;
-
- /* This may reorder frame. */
- rc = drbr_enqueue(ifp, fp->br, next);
fp->tx_mbuf_alloc--;
}
-
/* Stop looking for more work. */
break;
}
-
+ drbr_advance(ifp, fp->br);
/* The transmit frame was enqueued successfully. */
tx_count++;
@@ -9569,8 +9559,6 @@ bxe_tx_mq_start_locked(struct ifnet *ifp
ifp->if_drv_flags &= ~IFF_DRV_OACTIVE;
break;
}
-
- next = drbr_dequeue(ifp, fp->br);
}
/* No TX packets were dequeued. */
Modified: stable/9/sys/dev/oce/oce_if.c
==============================================================================
--- stable/9/sys/dev/oce/oce_if.c Mon Nov 25 19:53:46 2013 (r258583)
+++ stable/9/sys/dev/oce/oce_if.c Mon Nov 25 20:01:34 2013 (r258584)
@@ -1173,29 +1173,27 @@ oce_multiq_transmit(struct ifnet *ifp, s
return status;
}
- if (m == NULL)
- next = drbr_dequeue(ifp, br);
- else if (drbr_needs_enqueue(ifp, br)) {
+ if (m != NULL) {
if ((status = drbr_enqueue(ifp, br, m)) != 0)
return status;
- next = drbr_dequeue(ifp, br);
- } else
- next = m;
-
- while (next != NULL) {
+ }
+ while ((next = drbr_peek(ifp, br)) != NULL) {
if (oce_tx(sc, &next, queue_index)) {
- if (next != NULL) {
+ if (next == NULL) {
+ drbr_advance(ifp, br);
+ } else {
+ drbr_putback(ifp, br, next);
wq->tx_stats.tx_stops ++;
ifp->if_drv_flags |= IFF_DRV_OACTIVE;
status = drbr_enqueue(ifp, br, next);
}
break;
}
+ drbr_advance(ifp, br);
ifp->if_obytes += next->m_pkthdr.len;
if (next->m_flags & M_MCAST)
ifp->if_omcasts++;
ETHER_BPF_MTAP(ifp, next);
- next = drbr_dequeue(ifp, br);
}
return status;
Modified: stable/9/sys/ofed/drivers/net/mlx4/en_tx.c
==============================================================================
--- stable/9/sys/ofed/drivers/net/mlx4/en_tx.c Mon Nov 25 19:53:46 2013 (r258583)
+++ stable/9/sys/ofed/drivers/net/mlx4/en_tx.c Mon Nov 25 20:01:34 2013 (r258584)
@@ -935,22 +935,21 @@ mlx4_en_transmit_locked(struct ifnet *de
}
enqueued = 0;
- if (m == NULL) {
- next = drbr_dequeue(dev, ring->br);
- } else if (drbr_needs_enqueue(dev, ring->br)) {
+ if (m != NULL) {
if ((err = drbr_enqueue(dev, ring->br, m)) != 0)
return (err);
- next = drbr_dequeue(dev, ring->br);
- } else
- next = m;
-
+ }
/* Process the queue */
- while (next != NULL) {
+ while ((next = drbr_peek(dev, ring->br)) != NULL) {
if ((err = mlx4_en_xmit(dev, tx_ind, &next)) != 0) {
- if (next != NULL)
- err = drbr_enqueue(dev, ring->br, next);
+ if (next == NULL) {
+ drbr_advance(dev, ring->br);
+ } else {
+ drbr_putback(dev, ring->br, next);
+ }
break;
}
+ drbr_advance(dev, ring->br);
enqueued++;
dev->if_obytes += next->m_pkthdr.len;
if (next->m_flags & M_MCAST)
@@ -959,7 +958,6 @@ mlx4_en_transmit_locked(struct ifnet *de
ETHER_BPF_MTAP(dev, next);
if ((dev->if_drv_flags & IFF_DRV_RUNNING) == 0)
break;
- next = drbr_dequeue(dev, ring->br);
}
if (enqueued > 0)
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