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| author | John Fastabend <john.r.fastabend@intel.com> | 2010-07-01 13:21:57 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2010-07-02 21:59:07 -0700 |
| commit | f0796d5c73e59786d09a1e617689d1d415f2db44 (patch) | |
| tree | ecb17c65c5b6a162824a1e11fee24364852837f8 /include/net/sch_generic.h | |
| parent | 4ef6acff83222f4496ceef7d1f0ee9e50a5bb403 (diff) | |
| download | blackbird-op-linux-f0796d5c73e59786d09a1e617689d1d415f2db44.tar.gz blackbird-op-linux-f0796d5c73e59786d09a1e617689d1d415f2db44.zip | |
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 'include/net/sch_generic.h')
| -rw-r--r-- | include/net/sch_generic.h | 12 |
1 files changed, 8 insertions, 4 deletions
diff --git a/include/net/sch_generic.h b/include/net/sch_generic.h index ba749be1e354..433604bb3fe8 100644 --- a/include/net/sch_generic.h +++ b/include/net/sch_generic.h @@ -313,13 +313,12 @@ extern void qdisc_calculate_pkt_len(struct sk_buff *skb, extern void tcf_destroy(struct tcf_proto *tp); extern void tcf_destroy_chain(struct tcf_proto **fl); -/* Reset all TX qdiscs of a device. */ -static inline void qdisc_reset_all_tx(struct net_device *dev) +/* Reset all TX qdiscs greater then index of a device. */ +static inline void qdisc_reset_all_tx_gt(struct net_device *dev, unsigned int i) { - unsigned int i; struct Qdisc *qdisc; - for (i = 0; i < dev->num_tx_queues; i++) { + for (; i < dev->num_tx_queues; i++) { qdisc = netdev_get_tx_queue(dev, i)->qdisc; if (qdisc) { spin_lock_bh(qdisc_lock(qdisc)); @@ -329,6 +328,11 @@ static inline void qdisc_reset_all_tx(struct net_device *dev) } } +static inline void qdisc_reset_all_tx(struct net_device *dev) +{ + qdisc_reset_all_tx_gt(dev, 0); +} + /* Are all TX queues of the device empty? */ static inline bool qdisc_all_tx_empty(const struct net_device *dev) { |
