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-Currently two qdiscs support multiqueue devices. The first is the default
-pfifo_fast qdisc. This qdisc supports one qdisc per hardware queue. A new
-round-robin qdisc, sch_multiq also supports multiple hardware queues. The
+Currently two qdiscs are optimized for multiqueue devices. The first is the
+default pfifo_fast qdisc. This qdisc supports one qdisc per hardware queue.
+A new round-robin qdisc, sch_multiq also supports multiple hardware queues. The
qdisc is responsible for classifying the skb's and then directing the skb's to
bands and queues based on the value in skb->queue_mapping. Use this field in
the base driver to determine which queue to send the skb to.
-sch_multiq has been added for hardware that wishes to avoid unnecessary
-requeuing. It will cycle though the bands and verify that the hardware queue
+sch_multiq has been added for hardware that wishes to avoid head-of-line
+blocking. It will cycle though the bands and verify that the hardware queue
associated with the band is not stopped prior to dequeuing a packet.
On qdisc load, the number of bands is based on the number of queues on the
band 2 => queue 2
band 3 => queue 3
-Traffic will begin flowing through each queue if your base device has either
-the default simple_tx_hash or a custom netdev->select_queue() defined.
+Traffic will begin flowing through each queue based on either the simple_tx_hash
+function or based on netdev->select_queue() if you have it defined.
The behavior of tc filters remains the same. However a new tc action,
skbedit, has been added. Assuming you wanted to route all traffic to a
-specific host, for example 192.168.0.3, though a specific queue you could use
+specific host, for example 192.168.0.3, through a specific queue you could use
this action and establish a filter such as:
tc filter add dev eth0 parent 1: protocol ip prio 1 u32 \
projects / linux-2.6-omap-h63xx.git / blobdiff