diff options
| author | John Fastabend <john.r.fastabend@intel.com> | 2010-07-01 13:21:57 (GMT) |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-07-03 04:59:07 (GMT) |
| commit | f0796d5c73e59786d09a1e617689d1d415f2db44 (patch) | |
| tree | ecb17c65c5b6a162824a1e11fee24364852837f8 /drivers/net | |
| parent | 4ef6acff83222f4496ceef7d1f0ee9e50a5bb403 (diff) | |
| download | linux-f0796d5c73e59786d09a1e617689d1d415f2db44.tar.xz | |
net: decreasing real_num_tx_queues needs to flush qdisc
Reducing real_num_queues needs to flush the qdisc otherwise
skbs with queue_mappings greater then real_num_tx_queues can
be sent to the underlying driver.
The flow for this is,
dev_queue_xmit()
dev_pick_tx()
skb_tx_hash() => hash using real_num_tx_queues
skb_set_queue_mapping()
...
qdisc_enqueue_root() => enqueue skb on txq from hash
...
dev->real_num_tx_queues -= n
...
sch_direct_xmit()
dev_hard_start_xmit()
ndo_start_xmit(skb,dev) => skb queue set with old hash
skbs are enqueued on the qdisc with skb->queue_mapping set
0 < queue_mappings < real_num_tx_queues. When the driver
decreases real_num_tx_queues skb's may be dequeued from the
qdisc with a queue_mapping greater then real_num_tx_queues.
This fixes a case in ixgbe where this was occurring with DCB
and FCoE. Because the driver is using queue_mapping to map
skbs to tx descriptor rings we can potentially map skbs to
rings that no longer exist.
Signed-off-by: John Fastabend <john.r.fastabend@intel.com>
Tested-by: Ross Brattain <ross.b.brattain@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net')
| -rw-r--r-- | drivers/net/ixgbe/ixgbe_main.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/net/ixgbe/ixgbe_main.c b/drivers/net/ixgbe/ixgbe_main.c index a0b3316..7b5d976 100644 --- a/drivers/net/ixgbe/ixgbe_main.c +++ b/drivers/net/ixgbe/ixgbe_main.c @@ -4001,7 +4001,7 @@ static void ixgbe_set_num_queues(struct ixgbe_adapter *adapter) done: /* Notify the stack of the (possibly) reduced Tx Queue count. */ - adapter->netdev->real_num_tx_queues = adapter->num_tx_queues; + netif_set_real_num_tx_queues(adapter->netdev, adapter->num_tx_queues); } static void ixgbe_acquire_msix_vectors(struct ixgbe_adapter *adapter, |