Instead of 'pfifo_fast' we have just plain 'fifo_fast'.
No priority queues, just a straight FIFO.
This is necessary in order to legally have a seperate
qdisc per queue in multi-TX-queue setups, and thus get
full parallelization.
Signed-off-by: David S. Miller <davem@davemloft.net>
We have to have exclusive access to the given qdisc anyways, so
doing even more locking is superfluous.
Signed-off-by: David S. Miller <davem@davemloft.net>
Move the destruction of the old queue into qdisc_graft().
When operating on a root qdisc (ie. "parent == NULL"), apply
the operation to all queues. The caller has grabbed a single
implicit reference for this graft, therefore when we apply the
change to more than one queue we must grab additional qdisc
references.
Otherwise, we are operating on a class of a specific parent qdisc, and
therefore no multiqueue handling is necessary.
Signed-off-by: David S. Miller <davem@davemloft.net>
Make sch_tree_lock() lock the qdisc's root. All of the
users hold the RTNL semaphore and the root qdisc is not
changing.
Implement tbf_tree_{lock,unlock}() simply in terms of
sch_tree_{lock,unlock}().
Signed-off-by: David S. Miller <davem@davemloft.net>
Lock the root of the qdisc being operated upon.
All explicit references to qdisc_tree_lock() are now gone.
The only remaining uses are via the sch_tree_{lock,unlock}()
and tcf_tree_{lock,unlock}() macros.
Signed-off-by: David S. Miller <davem@davemloft.net>
It just wants the qdisc tree for the filter to be synchronized.
So just BH lock qdisc_root_lock(q) instead.
Signed-off-by: David S. Miller <davem@davemloft.net>
This allows less strict control of access to the qdisc attached to a
netdev_queue. It is even allowed to enqueue into a qdisc which is
in the process of being destroyed. The RCU handler will toss out
those packets.
We will need this to handle sharing of a qdisc amongst multiple
TX queues. In such a setup the lock has to be shared, so will
be inside of the qdisc itself. At which point the netdev_queue
lock cannot be used to hard synchronize access to the ->qdisc
pointer.
One operation we have to keep inside of qdisc_destroy() is the list
deletion. It is the only piece of state visible after the RCU quiesce
period, so we have to undo it early and under the appropriate locking.
The operations in the RCU handler do not need any looking because the
qdisc tree is no longer visible to anything at that point.
Signed-off-by: David S. Miller <davem@davemloft.net>
We are registering the device, there is no way anyone can get
at this object's qdiscs yet in any meaningful way.
Signed-off-by: David S. Miller <davem@davemloft.net>
When we have shared qdiscs, packets come out of the qdiscs
for multiple transmit queues.
Therefore it doesn't make any sense to schedule the transmit
queue when logically we cannot know ahead of time the TX
queue of the SKB that the qdisc->dequeue() will give us.
Just for sanity I added a BUG check to make sure we never
get into a state where the noop_qdisc is scheduled.
Signed-off-by: David S. Miller <davem@davemloft.net>
When code wants to lock the qdisc tree state, the logic
operation it's doing is locking the top-level qdisc that
sits of the root of the netdev_queue.
Add qdisc_root_lock() to represent this and convert the
easiest cases.
In order for this to work out in all cases, we have to
hook up the noop_qdisc to a dummy netdev_queue.
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently it is associated with a netdev_queue, but when we have
qdisc sharing that no longer makes any sense.
Signed-off-by: David S. Miller <davem@davemloft.net>
We liberate any dangling gso_skb during qdisc destruction.
It really only matters for the root qdisc. But when qdiscs
can be shared by multiple netdev_queue objects, we can't
have the gso_skb in the netdev_queue any more.
Signed-off-by: David S. Miller <davem@davemloft.net>
It just xor hashes over IPv4/IPv6 addresses and ports of transport.
The only assumption it makes is that skb_network_header() is set
correctly.
With bug fixes from Eric Dumazet.
Signed-off-by: David S. Miller <davem@davemloft.net>
The only behavior change is that we do not drop packets under any
circumstances. If that is absolutely needed, we could easily add it
back.
With cleanups and help from Johannes Berg.
Signed-off-by: David S. Miller <davem@davemloft.net>
Devices or device layers can set this to control the queue selection
performed by dev_pick_tx().
This function runs under RCU protection, which allows overriding
functions to have some way of synchronizing with things like dynamic
->real_num_tx_queues adjustments.
This makes the spinlock prefetch in dev_queue_xmit() a little bit
less effective, but that's the price right now for correctness.
Signed-off-by: David S. Miller <davem@davemloft.net>
The private area of a netdev is now at a fixed offset once more.
Unfortunately, some assumptions that netdev_priv() == netdev->priv
crept back into the tree. In particular this happened in the
loopback driver. Make it use netdev->ml_priv.
Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller